We’re going to look at the same four models as we did for Hurricanes Henri and Ida last summer. However, I just launched a complete redesign of this blog less than a week ago. That redesign will allow us to analyze the models in a way that’s much easier to compare, and hopefully much easier to understand. Let’s get started.

Big Picture Overview

When I look at the “big picture” meteorological setup, I immediately see just how similar this setup is to the October, 2021 nor’easter. That storm slammed into southern New England on 26 October, packing wind gusts over 100 mph (160 km/h) and heavy rains. Trees and power lines were down all over the place, knocking out power for several days. At one point all of Massachusetts south and east of the I-95 corridor was 100% without power.

Likewise, the current storm is a rapidly strengthening, or “bombing” cyclone. To be classified as a bomb cyclone, a storm must undergo a 24 millibar pressure drop in 24 hours. Will that happen with this storm? It remains to be seen, but it’s quite likely.

On the upper air map, you’ll see a large, powerful trough digging south over the Carolinas. That trough will rapidly strengthen, undergoing bombogenesis as it pull north. Look at all the energy, shown in the orange and red colors, off the coast of Georgia and Florida.

What Causes Bombogenesis?

There’s one major feature on the above map that jumps out at me. See the corridor of strong winds that stretches from northern Mexico to the southern tip of Florida? That’s the subtropical jet, which serves two purposes here.

1. Funnels a nearly endless stream of rich tropical moisture from the Gulf of Mexico into the developing bomb cyclone.
2. Exerts a west-to-east force on the southern edge of the nor’easter, which accelerates the spin of the upper-level low.

Both influences will have significant impacts on rain and snowfall totals, as well as wind speeds. We’ll dive into those details shortly. Furthermore, even without the subtropical jet, the storm will track pretty much right over the Gulf Stream. The Gulf Stream alone provides more than enough fuel for the storm to rapidly strengthen and maintain itself.

Similarities to the October, 2021 Bomb Cyclone

So just how similar are the meteorological setups between this storm and the October nor’easter?

• Both storms are bomb cyclones
• They both formed off the coast of Georgia and the Carolinas
• There is an immense amount of tropical moisture to tap into from the Gulf Stream
• Steering currents are nearly identical

This Bomb Cyclone will not Impact New England like the October Storm Did

The greatest impact of the October storm was the widespread power outages. As a New England native, I’ve been through some monster storms over the years. I’ve never seen power outages and downed trees anywhere close to the magnitude we saw following the October nor’easter.

Thankfully, it’s extremely unlikely you’ll see anything remotely close to the magnitude of power outages in October. The biggest difference is that the leaves are no longer on the trees. As a result, the surface area of the trees is far less, meaning that it takes much greater winds to do the same amount of damage. Additionally, the most vulnerable limbs, branches, and trees came down in the October storm. This time around, trees and limbs won’t come down nearly as easily. Don’t get complacent, though. The risk of power outages is definitely there with this storm.

However, where you may dodge one bullet, there are others you’ll have to content with. The shift from fall into winter brings in much colder air. The precipitation in the October storm all fell as rain. This time around, you’ll be dealing with snow. And lots of it.

A Better Storm For Comparison

In fact, for a much similar storm, forget the October nor’easter. Instead, go back to exactly 7 years ago today – 27 January, 2015. That day, the first Blizzard of 2015 dumped over 3 feet of snow across southern New England. It kicked off an infamous snowmageddon winter, that plunged the region into a months-long deep freeze.

All right, enough history. Let’s dive into the models.

Model Comparison: Bomb Cyclone Track and Timing

Let’s look at the same models we did with our analysis of Hurricanes Henri and Ida last summer. If you’ve forgotten those models, here they are.

For tracking and timing, you want to focus on the position of the center of the surface low, denoted by the red “L” on the map. In addition, note the timestamp on the upper left corner of the map. Those timestamps are in Zulu time, or UTC. Eastern time is 5 hours behind UTC. Don’t worry about the wind barbs for now. We’ll look at those in much more detail shortly. Click on any image to view it in full size.

As you can see, the American, European, and Canadian models are in very close agreement with each other. They show the the low passing just offshore of Cape Cod and the Islands around 00Z on Sunday (7 PM EST Saturday). The UKMET shouldn’t be discounted, either. It’s timing agrees with the other three models. Steering currents over the Appalachians can easily push the storm further offshore. However, it’s unlikely that it will pass any closer to the coast than what the GFS, ECMWF, or GDPS indicate.

Model Comparison: Bomb Cyclone Intensity (Pressure)

All right, it’s time to answer the million dollar question: will this storm bomb? To do this, we’ll need to figure out when each model expects the storm to reach its peak intensity, or minimum pressure. Then, we’ll compare the pressure at its peak intensity to the pressure 24 hours earlier. Remember, in order for a storm to be considered a bomb cyclone, it must undergo a 24 millibar pressure drop in 24 hours. Here is when each model expects the storm to reach its peak intensity.

Now, all we need to do is compare it to the same plots 24 hours earlier.

So do the models expect the storm to bomb? Here are their official predictions.

Models are usually not this assertive, but that’s a pretty definitive yes. The storm will bomb. Cue Toots and the Maytals.

Wind Forecast

Whenever a nor’easter undergoes bombogenesis, one thing is assured: there will be wind. Lots of it. So just how much wind will there be? You probably remember the October bomb cyclone, which brought 100-plus mph (160 km/h) wind gusts to southeastern Massachusetts. Thankfully, I’ve got some good news for you: you won’t see winds like that with this storm.

Look North to Canada for the Best Indicators of Potential Wind Speeds

The fiercest nor’easters get their winds from the pressure gradient between the bombing low and a strong high pressure system over southern Québec. But have a look at this. The high over Québec is much further north and east than it traditionally is for the really bad storms. In fact, it’s not over Québec at all. It’s actually over Newfoundland and Labrador.

Because the high is further away, the pressure gradient won’t be as tight. As a result, wind speeds won’t be as high as they would have been had the high been closer. Don’t get me wrong, it’s still a tight pressure gradient, and you’ll still get plenty of wind. It just won’t be as bad as it could have been. Combined with the expectation that the center of the low will pass offshore instead of right over Cape Cod and the Islands, I expect winds to be less than the bomb cyclone that hit New England last October. Let’s look at the models.

When I look at the models’ wind predictions, I prefer to look at the sustained winds about 400 to 500 meters above the ground, at 925 mb. In coastal areas, models can sometimes underestimate wind speeds when they try to calculate how friction and terrain impact the wind as it comes off the ocean. The 925 mb (400-500 meter) predictions remove those possible anomalies, and also give you the maximum potential wind speeds.

How Much Wind to Expect in New England

In the wind forecasts above, I don’t see any plausible scenario where the ECMWF (European) model forecast verifies. You just simply aren’t going to get winds that strong that far inland. Using the other three models, it’s clear that the strongest winds will be contained to the immediate coastal areas.

Areas that are exposed to the north along the South Shore and the Cape and Islands will see the greatest impacts from the wind. You’ll find the strongest winds on the Cape and Islands. Right now, my best guess is that sustained winds will peak in the 40-50 knot range in exposed areas across the Cape and Islands. Hurricane-force gusts are certainly possible, but I don’t expect anything close to the 100 mph gusts that ripped through during the October storm.

Temperature and Wind Chill: How Cold will the Bomb Cyclone Get?

Despite the availability of rich, tropical moisture, the bomb cyclone will have a very well-established cold core by the time it reaches New England. Furthermore, all of New England and the Canadian Maritimes will be on the cold side of the storm as it passes by. As a result, you should expect bitterly cold wind chills during the bomb cyclone. The models are all in agreement.

Expected Temperatures

Expected Wind Chills

When looking at temperatures and wind chills, you really need to look at the coast vs inland. Even in extreme conditions, the ocean still helps regulate temperatures near the coast. That being said, with the exception of Martha’s Vineyard, Nantucket, and possibly parts of the outer Cape, wind chills will struggle to get out of the single digits. If you’re inland, you’ll see sub-zero wind chills for pretty much the duration of the event.

Precipitation Type

With strong northerly winds, sub-zero wind chills, and everywhere on the cold side of the system, it should not be a surprise that this will be a snow event. Parts of the outer Cape and the Islands may briefly see a little ice mix in during the warmest part of the storm early Saturday afternoon. Other than that, it will be all snow.

On the models, we’ll look at the maximum temperature in the vertical column of air during the warmest part of the storm. Blue and purple indicates that the entire column is below freezing. You will see snow in those areas. Areas in green may briefly see some ice or sleet mix in early Saturday afternoon before changing back to all snow. That’s a result of air on the warm side of the storm wrapping around the top of the low as it approaches.

The European and British models do not calculate the maximum vertical temperature, so we’ll only consider the American and Canadian models. As you can see, their two predictions are nearly identical.

Snowfall Totals Will Be Measured in Feet, Not Inches

Whenever you have a storm that has both bitterly cold temperatures and an ample fuel supply of rich, tropical moisture, you’re going to get massive snowfall totals. However, there is a bit of a silver lining. All four models are showing noticeably less snow totals than they were yesterday. Unfortunately, they are still showing around two to three feet maximum snowfall totals for this bomb cyclone.

Because the GFS and GDPS models use the Kuchera Ratio, which is the most accurate, to predict snowfall, we’ll give the heaviest weight to those models. However, for a number of reasons, nailing down exact snowfall totals for a precise location is extremely difficult in this scenario.

1. The low still hasn’t really formed yet, so we don’t have any actual data from it to feed into the models.
2. The snowfall gradients are tight. A small wobble in the storm track can make a big difference in the snow totals. For example, take any of the above predictions and shift the snowfall totals 40-50 miles east or west.
3. A westward shift in the storm’s track may mean some areas – particularly parts of the Cape and Islands – may see more ice, sleet, or mixed precipitation on Saturday afternoon, which would reduce snowfall totals. Again here, a small shift in the storm’s track can make a big difference. In this scenario, inland areas would also see greater snowfall totals.
4. An eastern shift in the storm’s track would shift the precipitation shield east, meaning the heaviest snow could fall offshore.

How Much Snow Should You Expect?

We can give equal weight to all four models to determine where the heaviest snow will fall. Given my experience both with the models and with these types of bomb cyclones, I think the heaviest snow will set up in southeastern New England, along and east of the Interstate 95 corridor. Rhode Island will take a pretty good wallop, but will ultimately be spared the worst of the snowfall. Total accumulations will drop rapidly once you get west of I-95.

For the largest snow totals, I think 20 to 24 inches across Bristol and Plymouth Counties in Massachusetts is your safest bet at this point. That swath will likely spread across western Barnstable County (Cape Cod) and up into the far southern suburbs of Boston as well. 28 to 32 inches in a few isolated spots is certainly not out of the question, either, but I am not expecting widespread totals above 2 feet.

Summary

I know there’s a lot of information in this post, so let’s put it into a nice, clean table to summarize everything.

Conclusion

Like many other bomb cyclones, this is certainly a storm that you’re certainly going to want to take seriously. However, New England has certainly gone through far worse in the past. Make sure you stock up on what you’ll need for a few days, and then hunker down at home and enjoy it. The storm is fast moving, so it’ll be in and out in only about 24 hours. Then it’s just a matter of digging out, cleaning up, and getting back to your normal routine.

If you have any questions about anything related to this storm, please let me know in the comments below or reach out to me directly.

The post Wicked Bomb Cyclone Set to Pound New England with Fierce Winds and Heavy Snow appeared first on Matthew Gove Blog.

As I began planning my COVID-19 cross-country road trip last fall, my goal was to avoid the worst of winter across the midwest and northeast. Little did I know that the North Pole would come down and so kindly greet me as I crossed Tornado Alley. The Polar Vortex shattered all kinds of records and left several states – most notably Texas – under a significant emergency.

What is the Polar Vortex?

The Polar Vortex is a large area of very cold air that circulates around both the North and South Poles in the wintertime. Under normal conditions, the stability of the atmosphere keeps the Polar Vortex locked around the poles.

However, certain triggers high above the Earth can cause the Polar Vortex to rapidly destabilize and plunge southward (northward in the Southern Hemisphere) into the mid-latitudes. One particularly powerful trigger occurred in late January, 2021.

What Triggers the Polar Vortex to Destabilize?

To understand how the Polar Vortex behaves, we must travel about 20 to 50 km above the earth’s surface, well above where any weather happens or any airplanes fly. This part of the atmosphere is known as the stratosphere, and contains the far outer ranges of where weather balloons can travel.

Temperatures in the stratosphere are frigid. In the past 40 years, meteorologists have measured temperatures as low as -96°C (-141°F) in the stratosphere. Those cold temperatures are what holds the Polar Vortex in place above the poles.

Armed with that knowledge, you can probably deduce what causes the Polar Vortex to destabilize: a sudden and significant warming of the stratosphere. That’s exactly what happened in January, 2021. In less than 24 hours, the stratosphere warmed by 45°C, or 81°F. It was one of the most extreme stratospheric temperature swings ever recorded.

The January, 2021 destabilization was so powerful that it caused the Polar Vortex to completely fracture in half. One half plunged into the central and eastern parts of the United States and Canada. The other half dove south into Siberia. Temperatures in Yakutsk, Russia dropped to a bone-chattering -58°C (-73°F).

Have We Seen a Polar Vortex Like This Before?

You don’t have to go back very far to find a similar meteorological setup. In January, 2015, meteorologists observed a similar warming of the stratosphere above the North Pole. Shortly thereafter, the Polar Vortex split, sending parts of the US, Canada, and Russia into one of their coldest and snowiest winters ever.

One particularly interesting phenomenon is how the strong Polar Vortex makes the east coast of both the US and Canada so vulnerable to major snowstorms. Indeed, two blizzards crippled New England on 27 January and 15 February, 2015. That was only the beginning of a true snowmageddon winter.

Between the two storms, many locations in southeast New England received between 6 and 8 feet of snow. Boston was one of many cities that ran out of places to dump their plowed snow. Even once summer arrived, you’d still see some snow piles driving around. There was so much snow piled so high it took that long to melt. Not surprisingly, we all got a pretty bad case of cabin fever that winter.

Thankfully, 2021 did not suffer the same fate.

A Beautiful Day Across Central New Mexico

If you hadn’t looked at the weather before hand, you would have had no idea what lay ahead with the Polar Vortex. Temperatures were unseasonably warm as I made my way across the high deserts of eastern Arizona and western New Mexico.

As I descended into Albuquerque, the mercury topped 70°F (21°C). Even with strong winds, it made for very pleasant driving. However, once I climbed back out of the valley, things really began to change. Thick mid-level clouds replaced the warm sun and blue skies. You definitely had that feeling of “something crazy is about to happen” in the air.

Santa Rosa, New Mexico: Running Head-On into a Freight Train of Cold Air

If you’ve ever driven Interstate 40 across New Mexico, you know that it’s largely a vast emptiness of open desert. Aside from the occasional blink-and-you-miss-it town, you’re at the mercy of Mother Nature.

As I got further east of Albuquerque, that layer of mid-level clouds got progressively thicker, darker, and lower. Despite the ominous outlook, temperatures remained quite pleasant, hovering around 65°F (18°C). As I approached the town of Santa Rosa, New Mexico, things took a dramatic turn.

When I lived in Oklahoma as a meteorology student, I saw my fair share of wild weather. Whether it was EF-5 tornadoes, ferocious wildfires, thundersleet, a quakenado, or massive hail, it was nothing like what I saw punching through the Polar Vortex. Just when I thought I had seen it all, Mother Nature threw me something new. Wrap your head around this temperature drop.

For a different perspective, here is that same data on a time-series graph. Click on the graph to enlarge it.

And to think, this was just the tip of the iceberg.

Entering the Freezing Fog Twilight Zone in Texas

Between storm chasing, road trips, and photography adventures, I’ve driven across the Texas panhandle more times than I can remember. My favorite part of the drive is looking out at the open prairie. You can see forever, and really gives you a sense of freedom being on the open road.

What a contrast this trip turned out to be! As a result of the Polar Vortex invasion, we were treated to one of the rarest, and surprisingly, most dangerous weather phenomena in Texas: freezing fog.

What is Freezing Fog?

Freezing fog is no different than regular fog, with one distinct difference. Water droplets in freezing fog are supercooled, meaning that they are below freezing, but remain in liquid form.

Why do they remain as a liquid if they’re below freezing? Water molecules freeze much more efficiently when they are in contact with other particles versus being pure water. These particles can include sand, dust, minerals in tap water, and objects such as trees and vehicles.

Fog forms when water vapor condenses out of the air. Those fog droplets are pure water, and therefore freeze less efficiently.

Why is Freezing Fog so Dangerous?

Whenever water remains in a supercooled state, it poses an enormous risk to both vehicles and airplanes. Remember that we just reviewed how water freezes much more efficiently when in contact with other particles than when it is pure water?

When a supercooled water droplet comes into contact with something other than pure water, it instantly freezes. While freezing fog coming into contact with trees and grasses is largely harmless, it’s a much different story when it freezes on roads, overpasses, and your vehicle. Black ice is dangerous enough to begin with. It’s even more so in places like Texas that are not used to seeing it.

How Does Freezing Fog Form in a Hot, Arid Climate Like West Texas?

Warm air can hold much more moisture than cold air. Most of that moisture is in the air as water vapor. We measure it with either the dewpoint or the relative humidity.

When air cannot hold any more moisture, it reaches saturation. Any more moisture that gets added after that condenses out either as clouds or precipitation. There are two ways to reach saturation.

• Add moisture to the environment. You see this when the bathroom fogs up as you take a shower.
• Lower the temperature of the environment. There is no better example of this than when you see your breath on a cold day. Your warm breath has more moisture than the ambient cold air can hold, so it condenses out as a fog.

The powerful cold front I had punched through in eastern New Mexico had swept across the Texas Panhandle only a few hours earlier. Even in an arid environment like West Texas, the temperature dropped so extremely and rapidly that the air could not hold what little moisture it had. As a result, the excess moisture condensed into a freezing fog.

It was almost as if you could see Mother Nature’s breath.

Enter the Polar Vortex Twilight Zone

Being used to crossing the Texas panhandle in the summertime made this experience even more unique. The freezing fog shrouded everything in an eerie haze reminiscent of some kind of twilight zone. In addition, the Polar Vortex had been in place just long enough to start coating the landscape with a visible layer of ice. The setting late afternoon sun made that haze even eerier.

The deeper I got into Texas, the longer the bitter cold Polar Vortex air had been entrenched in place. Temperatures continued to plummet. Not surprisingly, the fog got thicker the further east I got. The setting sun slowly swallowed you into that twilight zone of darkness.

Things got even weirder as I crossed into Oklahoma.

Oklahoma? More Like Snow-klahoma!

How many times have you seen something bad happen and thought, “that won’t happen here”? I’ve done it more times than I care to admit, including this trip. Once I crossed the state line into Oklahoma, it didn’t take long for me to realize the full seriousness and severity of the Polar Vortex. At a gas station in Elk City, I noticed that both the windshield cleaner and the hand sanitizer had frozen solid as I fought 50 mph (80 km/h) winds and -11°F (-24°C) wind chills to fill my gas tank.

The Polar Vortex Flexes Its Muscles

Less than 48 hours after arriving in Norman, the first of back-to-back snowstorms hit the Southern Plains. After just a few days of wild weather we had shattered all kinds of winter weather records.

Most notably, the National Weather Service measured the coldest temperatures ever recorded in the State of Oklahoma. The only Oklahoma saw colder temperatures occurred in the late 1800s, when it was still the Indian Territory.

Thankfully, the snow didn’t stick around for very long. Temperatures rapidly warmed as the Polar Vortex pulled out of the area. In true Oklahoma fashion, we were walking around in shorts and t-shirts less than a week later as temperatures soared to 74°F (23°C).

Having Fun with Physics During a Power Outage in Sub-Zero Polar Vortex Temperatures

It often feels daunting when you lose power during a storm. Initial panic sets in that much more when the power goes out when it’s -5°F (-21°C) out and blowing over 30 mph (50 km/h). That’s the exact situation we found ourselves in the middle of the heaviest snow during my stay in Oklahoma.

I awoke in the middle of the night. As I reached for my phone to check the time, I noticed that it felt chilly in the house. I figured the thermostat had been turned down at night, and I didn’t think much of it. It was about 5:15 AM, so I decided to check the weather on my phone to see how cold it had gotten.

Much to my surprise, my phone could not connect to the internet. Not only was the WiFi out, I had no cell service, either. Being in the middle of a city of 125,000 people, something was very wrong.

I sat up and noticed that all of the night lights in the hallway were flickering and and off. I kept thinking, was I back in the twilight zone I was in driving here? At that point, I knew it was only a matter of time before the power company pulled the plug.

Less than 5 minutes later, the power went out for good. All you could hear was the wind, the snow, and the transformers blowing up nearby. At that point, there wasn’t much I could do, so I rolled over and went back to sleep.

Physics and Thermodynamics: An Alternate Source of Entertainment

If you’ve ever studied physics, chemistry, or thermodynamics, you’ve probably heard of the ideal gas law. While it has its limitations, the law is a good approximation of many gases, including air, under many conditions. Mathematically, it is defined as:

pV = nRT

where

• p is the pressure
• V is the volume
• n is the amount of gas
• R is the ideal gas constant
• T is the temperature

Now, here’s where the fun starts. I slept on an air mattress while I was in Norman. Because the power was out, the heat in the house did not work, so the house cooled off. In terms of the ideal gas law, we know that R is already constant. Inside the sealed air mattress, both the amount of air (n) and the volume (V) are also constant. We can reduce the ideal gas law to a simple relationship.

p ~ T

In layman’s terms, that equation just means that as temperature changes, the pressure will change in the same manner, and vice versa. We were now about 3 hours into the power outage, and the house was really starting to feel cold. As the temperature continued to drop, I could feel the air mattress getting softer and softer until I could feel my butt hit the floor underneath the mattress.

Here’s the best part. Shortly after 8 AM, the power came back on. It was cold in the house, so I decided to stay in my nice warm sleeping bag until the heat could work its magic. As the house warmed back up, the air mattress reinflated as the pressure inside increased. Before I knew it, the ideal gas law had lifted my backside up off the floor, and the house had returned to its normal temperature.

Up Next

As memorable as my stopover in Oklahoma has been, this is not the end of my dance with the Polar Vortex and Old Man Winter. Next week, we’ll continue east and see if it really was that wise of a decision to go camping in the mountains in Kentucky in February…in the middle of an ice storm. All that and more right here next Friday at 9 AM Pacific Time. See you then.

Top Photo: Heavy Snow Falls During the Polar Vortex
Norman, Oklahoma – February, 2021

The post Pioneering Peril: A Pandemic Polar Vortex in Tornado Alley appeared first on Matthew Gove Blog.

Lessons From My Road Trip to Oregon Last Summer

This trip is actually not my first foray out of Arizona during the COVID-19 pandemic. Last summer, I drove to Oregon to get a reprieve from Arizona’s summer COVID-19 spike and its relentless summer heat. In 2020, we had over 50 days of high temperatures above 110°F (44°C), which shattered the old record of 33. The Oregon trip was eye-popping, making me realize the complete callousness and carelessness of Arizona’s attitude toward the pandemic.

What a Difference Crossing the State Line Makes

On the Oregon road trip, my first gas stop was in Kingman, Arizona. I almost always stop in Kingman on trips that take me to California and Nevada. Kingman has always been safe and welcoming, and I have never once felt any hint of sketchiness or being unsafe.

I followed the same rules on the Oregon trip as I did this road trip. As a result, I wore N-95 masks every gas stop because I did not want to bring COVID-19 to Oregon with me. As I gassed up in Kingman, I noticed that a crowd had started to gather around me. They did not look happy, either. By the time I finished pumping the gas, the crowd was circling me much in the same way a group of lions closes in on a wounded gazelle. Thankfully, I left without incident.

Who Knew What to Expect Crossing into Nevada

Fast forward a few hours. I’m north of Las Vegas, and it’s time for my second gas stop. As I pulled into the gas station, every pump had a handwritten sign on it. That sign said in both English and Spanish, “No Mask, No Service”. I thought okay, feeling much less sketched out now.

Shortly after I started fueling, a car pulled into the other side of the pump. I was cautiously curious to see what would happen, since I had received death threats over masks in similar situations in Arizona. A middle-aged couple got out of the car, and they were both masked. This was the exact moment it started setting in just how completely batshit crazy Arizona was.

The lady in the other car started pumping gas, and the man started walking towards the convenience store. I noticed that he turned around after he got about half way to the convenience store. As he approached the car, he said “Honey, can you hand me my mask? I can’t go in without it.” That completely blew my mind. I was no more than 50 or 60 miles (80 or 100 km) from the Arizona border. What alternate universe have I ported into?

Oregon Took COVID-19 Seriously, Too

Even in very rural areas, both Oregon and Nevada took things seriously. Everyone wore masks in public, and you could see COVID-19 precautions in place everywhere. People kept their distance and largely stayed out of indoor public places. I felt things were much more controlled in Oregon and Nevada, and felt safer as a result.

All right, back to the present day.

Arizona

Things on this road trip were going to be different than the Oregon trip. So much has changed in just the six months since I drove to Oregon. Most notably, we now have several highly-effective vaccines available, as well as new antiviral treatments.

You don’t have to be on the freeway for long to realize how the pandemic has halted recreational travel. Unlike my summer road trip, my route this trip largely confined me to the Interstate system, whereas I only spent about 45 minutes of the 22-hour drive to Oregon on the Interstate.

You’ll quickly notice that once you’re out of the city, traffic on the freeway is almost exclusively semi trucks and big rigs. This is especially prevalent once you get on a major cross-country artery such as Interstate 40. It’s wintertime, and the pandemic is keeping everybody at home.

Even Mother Nature came through to help get the trip off to a good start. She treated us to spectacular morning driving conditions east of Flagstaff.

New Mexico

Entering New Mexico, I expected a very similar experience to the one I had in Nevada last summer. New Mexico did not disappoint. Right at the state line, they greet you with several signs.

• New Mexicans take COVID-19 seriously
• Masks are required statewide
• People arriving from out of state must quarantine
• If you break the rules, they will fine you.

I suspect that the reason New Mexico keeps reminding you of the rules is that if you exclude the international border, it’s surrounded on two of its remaining three sides by states that routinely flout COVID-19 restrictions and mock the pandemic. Additionally, both east-west arteries through New Mexico – Interstate 40 and Interstate 10 – directly connect those neighboring states that have made a mockery of the pandemic.

Even once you get away from the state line, you will be constantly reminded of the ongoing pandemic. Electronic signs in front of businesses instructed people to mask up, keep your distance, and stay safe. Interestingly, I also felt a sense of optimism in the air as businesses looked forward to adding capacity as COVID-19 cases continue to decline.

Ironically, the only time I really felt sketchy on the entire cross-country road trip occurred in one of the states I expected to feel the safest. The town of Tucumcari sits right on Interstate 40 about 30 miles west of the Texas state line. As I pulled into a gas station in town, I noticed that all of the vehicles there had Texas license plates. It was basically a repeat of what happened in Kingman last summer. It’s unnerving as hell having the angry crowd gathering around you, but once again, I was very grateful to get in and out without incident.

A Sneak Preview: An Icy Reception from the North Pole in Santa Rosa

As I passed through Santa Rosa, New Mexico, I punched through the strongest Polar Vortex to hit the US in recent memory. It brought some of the most wild weather I have ever seen on a road trip.

• Temperature dropped 45°F in 15 minutes
• Freezing fog leads into the twilight zone in the Texas Panhandle
• Wind chills dropped to -35°F (-37°C).
• The State of Oklahoma measured its coldest temperature ever.

Tune in next week for the full story, including pictures.

Texas

The Lone Star State continues to be in complete denial about the events of 2020. While I did not stop in Texas, you can see plenty from the highway as you pass through.

If you were dropped into the Texas panhandle without context, you would have no idea there was a once-in-a-century pandemic going on. The “Twilight Zone” effect from the freezing fog and the polar vortex only made this visit to Texas even weirder.

• Bars, restaurants, and stores in Amarillo were absolutely packed.
• There was not a mask, an effort to stay socially distanced, or any other attempts to contain COVID-19 to be found.
• You’ll see all kinds of political pro-Trump, anti-pandemic, and stolen election signs on the side of the highway.

The weather only continued to deteriorate as I got into Oklahoma.

Western Oklahoma

I always feel like I’m home when I cross the state line from Texas into Oklahoma. It was my route home after so many memorable storm chases, after all. While this road trip did feel a bit like storm chasing, tornadoes were the last thing on my mind as I headed back to my old stomping grounds. While I had prepared for cold weather, I was most certainly not ready for the bitter temperatures that welcomed me back to Oklahoma.

Shortly after dusk, I pulled off the freeway for one of my final gas stops of the day in Elk City, Oklahoma. When you exit onto the eastbound I-40 business loop, you have to travel for several miles through the open prairie before you reach Elk City proper. The gas station I had chosen was west of Elk City, in the open prairie.

Pulling in, I glanced up at the thermometer in the truck. The outside temperature had dropped to 14°F (-10°C). I thought to myself, no big deal, these temperatures are nothing new to me. It doesn’t take that long to pump a tank of gas. I put on my heavy coat, winter hat, and warm gloves. When I opened the door to step out, it completely took my breath away.

There’s a Reason the Chorus of the Musical Oklahoma! is so Famous

If you’ve ever driven across western Oklahoma, you’ll know that it is flat and open. When the wind blows, there is nothing to knock it down. No trees, no hills, no barriers. Nothing. In fact, the terrain slopes ever so slightly downhill as you go from west to east. When the wind has a westerly component, gravity can actually help accelerate the wind as it comes down the prairie.

What I had failed to realize while I was driving was that the polar wind was whipping down the Oklahoma prairie at about 50 mph (80 km/h). While I was dressed appropriately for the cold, I was not dressed for that kind of wind. The conditions in Elk City that evening combined to yield a wind chill of -11°F (-24°C). To add insult to injury, I had parked so the filler nozzle was on the upwind side of the truck, so there was nowhere to hide from the wind.

This was the exact moment it hit me just how severe this Polar Vortex would be. As I clamored back into the truck to warm up, barely able to feel my face, fingers, and toes, I happened to glance down. Both the windshield cleaner and hand sanitizer the gas station had put out were frozen solid. Not slushy or syrupy. Solid.

By the time I got to my friend’s house in Norman, temperatures had dropped into the single digits and bottomed out around -5°F (-21°C) the next morning. And that was only the beginning.

Up Next

Tune in next time to hear the full details of my tango with the Polar Vortex. Temperatures were much more reminiscent of northern Alaska in February than the southern plains. We’ll enter the twilight zone in Texas. In Oklahoma, experience power outages as wind chills dropped to -35°F (-37°C) while getting buried under a foot of snow.

Then, in true Oklahoma fashion, less than a week later, we were walking around in t-shirts and shorts as temperatures soared to 75°F (24°C). See you next week.

Top Photo: The Morning Sun Illuminates Palo Duro Canyon
Amarillo, Texas – August, 2019

The post COVID-19 Road Trip Journal: Wild Weather in the Wild West appeared first on Matthew Gove Blog.

Grand Canyon snow photography is a much different beast to tame than traditional Grand Canyon landscapes. While the goals of both types of photography remain the same, photos that really pop in the snow are often not the same awe-inspiring ones taken during the summer.

Plan Out Your Trip Beforehand

Winter weather introduces new layers of complexity and uncertainty to any kind of trip planning. At 7,000 feet above sea level, weather conditions at the South Rim can change rapidly and unexpectedly in the wintertime. As a result, your plan can go sideways in a hurry. Have a Plan B and a Plan C in place in case you need to unexpectedly spend the night somewhere or get stranded somewhere you didn’t expect.

Best Snow Routes to the Grand Canyon

The safest route to the Grand Canyon in the snow is via State Route 64 from Williams. The entire route stays below 7,000 feet elevation and has enough traffic that if you break down, someone will find you pretty quickly.

If you’re coming from Flagstaff, US-180 looks like a shortcut, but it comes with a catch. You’ll reach elevations of nearly 9,000 feet on a road that’s deserted and desolate as it snakes through the Kaibab National Forest north of the Arizona Snow Bowl. If you break down or get stuck, you’ll largely be on your own. Cell service is spotty at best. I’ve driven US-180 in blizzard conditions, so trust me. Taking I-40 West to Williams and going up Highway 64 is much safer.

What Areas of Grand Canyon National Park Do You Plan to Photograph?

You’ll be greatly disappointed if you think you can freely move around the park like you can in the summer.

• The North Rim closes for the winter in October, so you’re relegated to the South Rim.
• Roads outside of Grand Canyon Village are often closed after heavy snow.

I’ve sounded like a broken record in the past when I’ve told you to stay away from Grand Canyon Village when taking photos. However, snow photography is the one exception to that rule.

In fact, you want to do the exact opposite. Center your plan for snow photography around Grand Canyon Village. In this guide, we will focus on the village itself and nearby lookouts you can hike if roads are closed.

Time Your Arrival as the Winter Storm Pulls Away

The most dramatic Grand Canyon snow photo opportunities occur when the clouds start to part as the winter storm pulls away. The shadows and snow create a stunning contrast as the sun shines through broken clouds.

To correctly pull it off, you will have to thread a bit of a needle. Arrive too early and the heavy snowfall will obscure your view of the canyon. It will also make driving extremely treacherous. Arrive too late and you’ll miss the most dramatic views.

Dress Appropriately

The weather, elevation, and high desert climate present a unique challenge. The best advice I can give you is dress in layers. You will see large swings in temperature as the sun goes in and out of the clouds.

Additionally, wear warm gloves that allow you to operate your camera without taking them off. Wear snow boots or waterproof hiking boots. You can get into serious trouble from hypothermia or frostbite very quickly if your feet get wet.

Let Your Camera Acclimate, Too

Cameras hate going through rapid extreme changes in temperature. If you take your camera straight from the warm car out into the winter elements, you risk the lens fogging up and condensation forming inside the camera body. There are two strategies to reduce the temperature gap and prevent lens fog.

1. Store your camera in a cooler part of the car, such as the trunk.
2. Tuck your camera under your jacket when you first step out in the cold to let it gradually cool down.

The Grand Canyon’s high desert climate helps reduce lens fog and condensation. If it does happen to you (it’s happened to me plenty), just be patient. The lenses will clear up once the equilibrium is reached between the temperature inside camera and the ambient outdoor temperature.

Expect Winter Driving Conditions and Road Closures

Winter driving in Arizona’s high country is not for the faint of heart. Expect rapidly changing conditions, occasional white-outs, and slow going. You don’t have to get much north of Phoenix to get into the snow and ice, either. The climb heading north out of Black Canyon City on Interstate 17 – only about 20 miles (30 km) from the northern fringes of Phoenix – is often where I first run into snow and ice.

Drive a 4×4 and Carry Tire Chains

The biggest mistake I see inexperienced drivers make in the snow is driving like they would on dry pavement. Unfortunately, this behavior leads to spin-outs, crashes, getting stuck, and winding up in the ditch. Even with four wheel drive, some people think they can drive normally.

Here’s the truth. Four wheel drive will help you get going from a stop and will give you some traction going around corners. Contrary to popular belief, it does absolutely nothing to help you stop. In fact, in certain instances, it can actually hinder your ability to stop safely.

Tire chains are the secret weapon to helping you stop and maintain traction in the snow. They’ll also help you get going and make it up hills if you don’t have four wheel drive. You can buy chains at most auto parts stores in the west. Buy tire chains with actual chain links on them. The ones that look like the cables you wire your television with do not give you much extra traction.

Before setting off, practice putting your chains on in your driveway. You don’t want to try and figure out how to chain up on the side of the freeway in white-out conditions. Arizona does not have workers at the chain up areas to install your chains for you the way California dows.

Finally, don’t drive faster than 25-30 mph (40-50 km/h) with chains on. Take it slow, stay in control, and you’ll have a great time at Grand Canyon.

Tip: If you’re coming from Phoenix, there is a chain-up area on Interstate 17 just north of the McGuireville Rest Area, which is near Mile Marker 300 in the Sedona area.

Expect Roads Leading to and Within Grand Canyon National Park to Be Closed

Encountering road closures is one of the main causes of frustration trying to get around in winter weather. Grand Canyon country is no exception. Always check road conditions before you set off, either on Google Maps or directly with the Arizona Department of Transportation or the National Park Service.

Roads That Almost Always Close During Heavy Snow

• Desert View Drive (SR-64) from Grand Canyon Village to the Desert View Watchtower and East Entrance Station
• Hermit Road from Grand Canyon Village to Hermit’s Rest
• State Route 89A through Oak Creek Canyon from Sedona to Flagstaff

Roads That Frequently Close During Heavy Snow

• Interstate 17 between Munds Park and Flagstaff
• US-180 between the Arizona Snow Bowl and Grand Canyon Junction/SR-64.

Roads That Generally Stay Open, But Will Close if Conditions are Bad Enough

• Interstate 40 between Ash Fork/SR-89 and Winona, which is east of Flagstaff
• State Route 64 between Williams and the main entrance to Grand Canyon National Park
• US-89 from Flagstaff to Page

Carry Winter Survival Gear

You’ll be driving through remote and desolate territory as you travel from Flagstaff or Williams to the Grand Canyon. If you break down, spin out, or get stuck, you want to ensure you can stay warm and safe until help arrives. Winter storms in Arizona’s high country can strike swiftly and fiercely. Things can go sideways on you in a hurry if you’re not prepared.

At the bare minimum, you should carry with you:

• Extra water
• Extra food. Snacks such as cereal, granola bars, and trail mix work great.
• A flashlight and extra batteries
• A blanket or sleeping bag
• A change of clothes
• An extra pair of shoes or boots
• A snow shovel
• An ice scraper and/or snow brush
• Jumper cables
• Keep your gas tank at least half full. If you get stranded, you can run the heat to stay warm.

It May Take Significantly Longer Than Normal to Get to Grand Canyon

You need to drive according to the conditions. I cannot stress this enough. If you’re driving though heavy snowfall or white out conditions, expect to be moving at a crawl, even on major freeways such as I-17 or I-40.

Want some proof? Here’s a true story. I took a snow adventure to the Grand Canyon in January, 2017. That day, the snow level dropped down to about 4,500 feet. Coming from Phoenix, I made the climb out of the Verde River Valley (about 3,000 feet) to the top of the plateau (about 6,500 feet) on Interstate 17.

As I crossed that magical 4,500 foot elevation threshold, things transitioned from normal overcast driving conditions to a white out blizzard in a matter of minutes. By the time I reached the top of the plateau, I-17 was completely snow packed and traffic slowed to about 15 mph (25 km/h). Keep in mind, the normal speed limit is 75 mph (120 km/h).

I couldn’t believe how many idiots I saw go flying by in the left lane trying to drive the normal speed limit. They were going way too fast for the conditions. Here’s the kicker. For every vehicle that went flying by, I saw them less than 5 minutes later spun out in the ditch waiting for a tow truck. It took me over six and a half hours that day to drive from Phoenix to the Grand Canyon. It was worth every one of those extra minutes to get there safely.

Use the Main Entrance to the South Rim at Tusayan

Desert View Drive always closes when there is any appreciative snow accumulation. As a result, the South Rim’s main entrance is usually the only entrance to Grand Canyon National Park that is open. The main entrance brings you to Grand Canyon Village, which has the Visitor’s Center, restaurants, hotels, and all the other comforts you need. You’ll likely be cut off from those comforts if you try to use any other entrance.

Note: During the COVID-19 pandemic, the National Park Service has permanently closed the East Entrance to the South Rim (SR-64 from Cameron, AZ) to protect the Navajo Nation. You must use the main entrance at Tusayan to enter the park.

Snow Photography is Different from Regular Landscape Photography

This is especially true at Grand Canyon.

Think of the “classic” Grand Canyon photo you may see hanging in a bookstore or coffee shop. What was the photographer trying to capture? The Grand Canyon’s massive size? The geology and breathtaking relief? Its brilliant colors? Its native culture? The Colorado River?

If you’re thinking “All of the Above”, let me welcome you to the challenges of Grand Canyon landscape photography. As spectacular as the canyon is, it is incredibly difficult to capture all of its elements in a single photo.

Thankfully, Grand Canyon snow photography is much simpler because you’re focusing on one thing. The snow is the main subject of your photo. As for the geology, the colors, and everything else, they’re what takes a good photo and makes it great. It’s just icing on the cake.

A Grand Canyon Snow Photography Strategy

Photographing snow at Grand Canyon requires a vastly different strategy than classic Grand Canyon landscape photography. Unless the snow level gets really low – I’m talking almost all the way down to the river low – forget about the “full canyon” photos you gravitate towards in the summertime.

Instead, you want to focus on capturing snow on the canyon walls. You can use either the outer walls of the canyon or the spires, temples, and buttes inside the canyon. I actually find the most dramatic photos are when you use a combination of both. You’ll get a distinct foreground and background that will provide pronounced depth to an already dramatic photo.

You also want to make sure your viewing angles are correct. There is an endless selection of lookouts along the South Rim for you to find the perfect photo op. If you’re not seeing anything looking left from one of the lookouts, look to the right. At Grand Canyon, what looks terrible in one direction is often spectacular looking the other direction.

Additionally, shadows inside the canyon add flare and depth to photos any time of year. Low sun angles in the winter maximize this effect. After mapping out your favorite lookouts, come back throughout the day. Changing sun angles drastically alter the scenery throughout the day. A terrible photo op at 10 or 11 AM may turn into one of the best photos you’ve ever taken at 4 PM.

Don’t Be Afraid to Use the Weather to Make Your Grand Canyon Snow Photos Dramatic

You are taking snow photos after all.

Weather is one of the easiest and most effective ways to make any landscape photo really “pop”. Just have a look at some of my storm chasing photos from Oklahoma or Kansas.

An exiting winter storm presents an incredible opportunity to add weather to your Grand Canyon snow photography. To take advantage of this opportunity, have a look at the weather radar and head to the part of the South Rim from where the storm is leaving. If it’s moving east, head to the east end of the South Rim. Go west if the storm is leaving the western part of the park.

Regardless of where you’ve set up to take pictures, the most common weather features you’ll see include:

• Snow or rain squalls moving across the canyon
• Dramatic lighting from the sun poking through broken clouds

Take Advantage of Low Winter Sun Angles to Capture Soft Light on the Brilliant Canyon Walls

If you look at Grand Canyon photos in coffee shops, art galleries, magazines, and advertisements, you’ll notice a common thread. Most of them were taken close to sunrise or sunset. That’s because the mid-day sun creates harsh contrasts inside the canyon, especially in the summer.

Luckily, the effect of harsh contrasts is minimized in the wintertime because the sun angle is at its lowest. Regardless of what the date on the calendar is, the best time of day for any Grand Canyon photography is the 60 to 90 minute window after sunrise or before sunset.

Keep the sun somewhat behind you and use the strategies we just discussed in those time windows. Your photos will be absolutely stunning.

Tip: At the South Rim, you’ll find the best photo ops looking west (left) in the morning and east (right) in the evening.

Don’t Get Frustrated if You Can’t See Inside the Canyon

You can still take great pictures.

All right, time for a quick meteorology lesson. Air parcels are constantly moving up and down through the atmosphere. Warm air near the ground rises. As it gains altitude, it starts cooling down.

Cold air cannot hold as much moisture as warm air. The air parcel eventually cools off enough where it cannot hold any more moisture. At that point, the moisture condenses out in the form of clouds. The height at which this occurs is called the Lifted Condensation Level, or LCL. If there’s enough upward force to keep the parcel moving upward, additional moisture that condenses out will fall as rain or snow.

In most synoptic (large) scale storms, the LCL is at most only a few hundred meters (1,000 to 2,000 feet) above the ground. Keep in mind that the South Rim sits about 7,000 feet (2,100 meters) above sea level. As the storm passes over the Grand Canyon, its width, steepness, and depth allow the LCL inside the canyon to fall well below the elevation of the rim. As a result, clouds and precipitation obscure your view of the canyon.

If you encounter an obstructed or obscured view of the canyon, don’t panic. Your efforts haven’t been for not. You can still take great pictures. Here are a few ideas.

• Take a “snow globe” or “winter wonderland” photo from the rim trail or the surrounding forest
• Take close-up photos of plants or animals
• Lean into the punch and let the obscured view add a touch of mystery to your Grand Canyon snow photos.

Don’t Get too Close to the Edge

Just because you see snow accumulations does not necessarily mean there’s actually solid ground underneath it. Snow has an uncanny ability to defy physics that way. Don’t join the infamous club of people who have fallen into the Grand Canyon.

• Keep bushes or trees between you and the edge. You know for sure that they’re attached to solid ground.
• Look for footprints in the snow. They are a good indicator that there is solid ground underneath the snow.
• Use a long stick or a hiking pole to prod the ground in front of you if you’re near the edge
• Stick to areas that have railings and other safety mechanisms in place

Hike the Rim Trail to Gain a Different Perspective

The Rim Trail runs 13 miles (21 km) along the South Rim from Hermit’s Rest to the South Kaibab Trailhead. Running right through the heart of Grand Canyon Village, the trail is easily accessible from the Visitor’s Center, the museums, and the lodges. Best of all, it’s paved, routinely plowed, and flat.

You don’t have to go far to get away from the crowds. Hiking for just 10 or 15 minutes east or west of Grand Canyon Village is often all it takes. I often go further than that. If Desert View Drive or Hermit Road is closed, the Rim Trail provides at least some access to lookout points beyond Grand Canyon Village.

Tip: Do not hike any trails with steep hills or switchbacks, such as Bright Angel or South Kaibab. They are very icy, slippery and treacherous after a winter storm.

Photo Opportunities that are Accessible by Car

If you prefer not to hike, no need to worry. There are plenty of lookout points you can drive to. In the immediate aftermath of the snowfall, road closures may initially restrict where you can go. However, both Desert View Drive and Hermit Road generally re-open within 24 to 48 hours after the storm ends.

Desert View Drive

• Yaki Point / South Kaibab Trailhead (also accessible via the Rim Trail)
• Moran Point
• Lipan Point
• Desert View Watchtower

Hermit Road

Hermit Road is open to passenger vehicles during the months of December, January, and February. Drive the full 7 miles (11 km) out to Hermit’s Rest. The lookouts along the way have some of the best views of Grand Canyon.

Grand Canyon Village

If roads or closed or you’re not feeling that adventurous, take advantage of the incredible snowy scenery within Grand Canyon Village.

• Mather Point (behind the Visitor’s Center)
• Bright Angel Trailhead and the Lodges on the Rim
• Yavapai Point and the Geology Museum

Don’t take photos through the glass from inside the Yavapai Geology Museum. You risk reflections, grit on the windows, and poor lighting appearing in your photos.

If You Don’t Want to Hike or Drive, Take the Shuttle

Grand Canyon National Park operates free shuttles so you can access lookout points and more throughout the South Rim. In addition to serving Grand Canyon Village, you can take the shuttle to Hermit’s Rest, the South Kaibab Trailhead, and Tusayan.

Shuttle service is pared down right now due to the COVID-19 pandemic. You can still use it to access lookout points within Grand Canyon Village and at the South Kaibab Trailhead. Shuttle service to Hermit’s Rest will resume in March.

For up to the minute information on shuttle schedules and routes, please visit the Grand Canyon National Park website.

Know Your Limits

Any time you enter an extreme environment, even the smallest of mishaps can turn into full-blown disasters. While Grand Canyon gets most of its notoriety from its scorching summer conditions, winter can be just as unforgiving.

Know the limits of not just yourself, but also your vehicle and your equipment. When in doubt, always remember my rule. If you don’t feel comfortable doing something, then don’t do it.

Drink Plenty of Water and Bring Snacks

While Arizona is best known for its sunshine and warm weather, winters at Grand Canyon are nothing to take for granted. The combination of the cold, the high desert, and the elevation can be deadly.

The threats from these winter conditions at Grand Canyon are surprisingly similar to the threats in Arizona’s low deserts in the summer. The only difference is that you risk hypothermia instead of heat exhaustion. Indeed, you won’t realize you’re dehydrating until it’s too late.

While you don’t need to drink as much water as you do to survive in the low desert summer, you should carry a water bottle and sip it throughout the day.

Additionally, you burn more calories at high elevation than you do at sea level. The cold further compounds that. Snacking throughout the day is the best way to keep your energy levels up. Just be careful if you’re eating lots salty snacks. You don’t want to dehydrate yourself anymore than you have to.

Conclusion

Seeing the Grand Canyon under a fresh blanket of snow is one of the most beautiful and spectacular sights you’ll ever see. You’ll capture photos that are second to none. However, snowstorms in Arizona’s high country are not to be taken lightly. Come prepared and stay within your limits, and you’re bound to have an experience you won’t soon forget.

Top Photo: The Sun Begins to Set over Grand Canyon After a Major Winter Storm
Grand Canyon National Park, Arizona – January, 2019

The post Grand Canyon: A Complete Guide to Stunning Winter Photography appeared first on Matthew Gove Blog.

The post Adventure Series: The Grandest of Snowfalls appeared first on Matthew Gove Blog.

In the typical surface-based thunderstorm, warm, moist air is lifted from the surface or ground-level into the updraft of the thunderstorm. The cloud base of surface-based thunderstorms is typically only a few hundred feet above the ground. However, if we pass a powerful cold front through the area, such as we did right before the thundersleet, we create a very stable layer at and just above the ground level. In this case, that stable layer was only about 3500 feet deep, but that’s still plenty deep to prevent parcels from being lifted from the surface into the updraft. If we lift a parcel from the bottom of the unstable layer (just above 3500 feet), there is sufficient instability to form thunderstorms. The base of the thunderstorm will be a few hundred feet above the bottom of the unstable layer, which in this case would be around 3700 or 3800 feet above the ground (just under 5000 feet above sea level), hence the term high base thunderstorm (or elevated thunderstorm). This phenomenon can be showed very well in the Norman soundings from March 2nd.

Norman, OK Sounding – March 2nd at 6 AM CST  

Norman, OK Sounding – March 2nd at 6 PM CST

A Few Observations from the Soundings

The line of convection formed about 15 miles south of the Norman sounding release site shortly after the 6 AM CST sounding. The high-based instability at 6 AM was strong enough to both create robust updrafts and sustain them throughout much of the day. One key observation that led to the formation of thunderstorms was that the temperature at the bottom of the unstable layer (750 mb or about 3500 feet) was around 50°F, warm enough to generate quite a bit of high-based instability in these conditions. The surface temperature is completely irrelevant for the formation of this type of high-based thunderstorm. The surface temperature could have been 50 below on March 2nd and thunderstorms would havve still been able to form.

By 6 PM CST, the bottom of the unstable layer had cooled from 50°F to 32°F and the mid-levels of the atmosphere had warmed, significantly reducing instability. While the thundersleet had ended hours earlier in Norman, the line of convection had moved to the east, but was quickly falling apart due to the lack on instability.

A Similar Event in 2013

A very similar event occured in northwest Oklahoma on April 9, 2013. That day began as a typical spring cold front/dryline setup for severe weather, and a couple surface-based supercells formed near the Texas/Oklahoma border south of Woodward, OK. A very shallow, yet very powerful cold front pushed through the area, dropping surface temperatures from the 70s into the upper 20s. However, there was so much instability aloft and the supercells were well-enough established that the front was not deep enough to cut off the updraft of the supercells. The result was that the supercells transitioned from surface-based to high-based and continued on their merry way, dropping tennis ball sized hail in the areas south of Woodward despite surface temperatures of only 27°F.

In the next posts, I will look at what caused the transition from snow to sleet as the thunderstorms passed, as well as look at some of the radar data from the event.

The post Okla. Thundersleet Part 2: How The Thunderstorms Formed appeared first on Matthew Gove Blog.

A Few Observations from the Thunderstorms

As I’m sure you know, the dynamics inside of thunderstorms are quite complex. These storms provided a very unique observation of mid-level temperature advection that could be seen by simply looking out the window. A light snow had been falling for much of the day prior to the thunderstorms arriving. As the thunderstorms passed overhead, the snow would change over to sleet and drastically increase in intensity. As soon as the thunderstorms passed, the sleet would lighten up and then change back over to snow. The process would repeat as the next cell approached. Exactly why this happens will be covered in later posts.

Even though the outer edges of these thunderstorms just skirted the south side of Norman (the cores of the storms passed between Norman and Purcell), we still got some impressive sleet totals. I measured close to 2 inches of sleet on my back patio from these storms, and I would guess that Noble and Purcell saw even more.

Thundersleet Accumulations on My Patio

Coming Up Next: Analysis of the Setup and the Thunderstorms

In my next post(s), I will dive into some deeper analysis of the meteorological setup that caused the thunderstorms to form, as well what caused the transition to sleet as the thunderstorms passed. Both of these topics are quite fascinating, so stay tuned in the coming days.

The post Oklahoma Thundersleet Part 1: Video and Observations appeared first on Matthew Gove Blog.

GOES Satellite Image – Friday at 6:30 AM CST/4:30 AM PST

Storm Brings Much-Needed Rain to Drought-Stricken California

The best news is that this storm will bring some much-needed rain to the areas in California that have been hit so hard by drought this winter. May areas from the Central Valley area all the way down the Interstate 5 corridor to the Mexican border could see up to 2 inches of rain. Temperatures in the valleys and at the coast will be in the 40s and 50s, so winter weather is not a threat at the lower elevations. Unfortunately, whenever you get a large amount of rain falling over a drought-stricken area in a short period of time, flash flooding and landslides will be a concern, especially in areas recently impacted by wildfires.

Conditions up in the mountains will be a vastly different story. Strong winds and heavy snow will create dangerous conditions across the Sierra Nevadas to the south and southeast of Lake Tahoe, including Yosemite National Park and Mammoth Lakes. A Winter Storm Warning is in effect for much of these areas above 6,000 feet until 4 PM PST Saturday. With wind gusts up to 80 mph possible and and snow accumulations of 12 to 24 inches possible, it would not surprise me if this was upgraded to a Blizzard Warning later on. Further to the south where snow is less of a threat, a High Wind Warning is in effect for the Kern County Mountains and the Interstate 5 corridor through The Grapevine until 4 PM PST today. South winds of 30-50 mph with gusts to 90 mph are possible.

GFS Forecast Rainfall/Liquid Equivalent Through 4 AM PST Sunday

What Lies Ahead for this Storm After California

Like many of these storms, it will weaken as it crosses the Rocky Mountains and its supply of moisture is cut off. As it ejects over the southern plains, it will interact with an Arctic airmass plunging southbound out of Canada. As a result, it will bring light winter precipitation (snow, sleet, and freezing rain) and a cold rain to parts of Kansas, Oklahoma, and north Texas. In Oklahoma, freezing rain and sleet will be the primary modes of precipitation, with up to 1/10 of an inch of ice accumulations possible with locally higher totals, especially across eastern Oklahoma. Heavier snow totals will be possible up in Kansas, with mainly rain to the south down in Texas.

The storm will continue to move to the ENE once it crosses the central and southern plains. The exact location, timing, and intensity of the storm once it reaches the east coast is still very much up in the air, so stay tuned. Right now, there is the potential for heavy snow near the east coast, but it appears to be confined to a fairly localized area if it does indeed happen. The models should be able to get a much better grip on the storm once it comes ashore and the Weather Service can get accurate data from inside of it.

The post Beautiful and Impressive Storm Coming Ashore in California appeared first on Matthew Gove Blog.

Outlook for New England

A weak disturbance has been tracking eastbound down Interstate 40 for the past few days. That system dropped 1 to 3 inches of snow on Friday over parts of eastern Oklahoma, Arkansas, and North Texas. As of 7 AM EST today, the upper-level disturbance was centered near Memphis, Tennessee, and should be centered near the Tennesee – North Carolina border by daybreak on Sunday. Temperatures south of northern Virginia will be above freezing, so any precipitation will fall as rain the Carolinas Sunday morning. Any precipitation that falls will be very light, if it falls at all. The heavier precipitation will be well offshore.

Also beginning Sunday morning, a surface low will begin to develop off the Mid-Atlantic coast. Some of the GFS runs from earlier today brought the system right up the east coast, but this morning’s run is much more in agreement with the Eurpoean model. Both models are now showing the surface low developing well offshore and moving northeast, staying sufficiently offshore of the east coast of both the United States and Canada. The surface low is being “sling-shotted” around the upper-level trough, so it is moving faster and will be further offshore than models earlier this week were showing.

Sfc Wind/Pressure/Precip – Saturday at 7 PM EST

The storm may pass close enough to the coast to bring some gusty winds and light snow to eastern New England, but this will not be major system, and I am not anticipating any significant travel issues at this time. Wind gusts could be as high as 20-25 knots, and any snow accumulations will be minimal (less than 1 inch).

Another surface low may develop just south of New England late Sunday night into Monday and rapidly move northeast. This system could bring 20-30 knot winds and a few inches of snow to southern New England. Precipitation should end by Monday afternoon, but some gusty winds may remain through Monday night. The models are not in agreement with this system (some don’t even develop this low at all), so stay tuned.

Sfc Wind/Pressure – Monday at 1 AM EST

Southern Plains

After another Arctic cold front comes racing down the plains on Sunday, another disturbance will eject across the southern plains on Monday. Models are currently hinting that any precipitation that falls Monday morning along and south of Interstate 40 in Oklahoma may start as a winter mix before quickly changing over to all snow. Forecast soundings from the Oklahoma City Metro are showing that this changeover could occur as soon as sunrise, and depending on exactly when the precipitation starts, it could just start as snow, too.

Further to the south, a much deeper mid-level warm layer will be present, which will delay the changeover to snow to later in the day. Areas right along the Red River may not even make the transition at all. The good news is that the bulk of the precipitation should fall well north of this area, so widespread significant icing is unlikely. The highest precipitation totals appear to be in the NW, NE, and SE quadrants of Oklahoma, including the entire Oklahoma City Metro, and much of Arkansas. This could change as we get closer to the event, however.

As far as snowfall totals go, I would expect to see a lot of reports in the 1 to 3 inch or 2 to 4 inch range, but it’s still too early to talk specifics on exact locations. The Oklahoma City Metro will likely once again be right on the edge of lighter snow and heavier snow, so a small shift in track could mean a big difference in snow totals. A few isolated 5 to 6 inch totals may pop up in eastern Oklahoma and northern Arkansas. Keep in mind that these will likely change as the event approaches and things start to come into focus a bit better, so stay tuned for more.

The post Winter Weather Outlook for Sunday Through Tuesday appeared first on Matthew Gove Blog.

Tuesday, February 4th: Boston, MA and Washington, DC

The winter storm that passed through Oklahoma on Sunday is currently centered over the Tennessee valley and will be well offshore by sunrise on Tuesday, and will bring precipitations along the coast of the Mid-Atlantic and Southern New England. Areas north of the Mason-Dixon Line could see a few more inches of snow, with some isolated higher totals possible, especially along the Connecticut coast and Long Island. All precipitation will end by 11 PM EST tonight.

The second winter storm will eject over the southern plains from the Rockies tonight and will be moving rapidly to the east/northeast on Tuesday. This storm will be approaching the east coast by Wednesday morning. I’ll start by looking at the GFS model output of the big picture, and one of my favorite winter weather plots, the maximum temperature in the precipitation column (surface to 500 mb), which is a great way to help determine what type of precipitation will fall. If you are north of the thick black line (the 0°C max temp line), you will get snow. South of it, we will need to look at surface temperatures and soundings to determing the type of precipitation.

 500 mb Wind/Height – Tuesday at 7 PM EST

The Boston area will not see any precipitation between about 7 PM EST Monday and 7 AM EST Wednesday. In Washington, DC, precipitation should start between 10 PM EST Tuesday and 1 AM EST Wednesday. Since we are looking at one specific location, let’s fast forward and look at a couple soundings from Washington, DC after daybreak on Wednesday. Precipitation will end in Washington by midday Wednesday

Washington, DC Forecast Sounding – 7 AM EST Wednesday

The most significant feature I notice on these soundings is that the low-level temperatures all stay above freezing, so any precipitation that falls will fall as a cold rain. However, I should note that the surface temperatures are very close to freezing, so just a few degree drop in surface temperature could result in freezing rain instead.

Thursday, February 6th: Washington, DC and Raleigh, NC

Things appear to quiet down for at least a few days beginning on Thursday. I do not anticipate any travel problems on Thursday, as skies will clear overnight Wednesday in both Washington and Raleigh, and temperatures will fall into the 20’s and 30’s. Skies will be partly cloudy by sunrise on Thursday, with high temps in the 40’s across all of North Carolina on Thursday.

Sunday, Feburary 9th: Raleigh, NC and Boston, MA

Before I even begin, I do want to point out that Sunday is still 6 days away, so confidence in this forecast is low. A powerful upper-level low is set to come off the Rockies and eject across the southern plains on Saturday, bringing more wintry precipitation to parts of Kansas, Oklahoma, and Texas. This storm is taking a much more southerly track than the previous two, which will likely allow it to tap into rich, Gulf of Mexico moisture. Models are currently showing the upper-level low centered near Dallas, TX at 7 AM EST on Sunday, and the surface low centered over Alabama. Below you will find the ECMWF model output for Sunday at 7 AM EST. Do take note that this setup is screaming “Textbook Significant Coastal Storm” at me, but it will likely not begin to impact the coast before Sunday night.

ECMWF Forecast – 7 AM EST Sunday, Feb. 9th

The nice thing about storms that track further south is that the warm sector is plenty warm, which will keep temperatures in North Carolina well above freezing on Sunday. There will likely be rain around on Sunday, but I do not anticipate wintry precipitation at this time, but be aware that things could change between now and Sunday.

Further up the coast in Boston, it will be cold, but there will not be any precipitation at all on Sunday. Models are showing the developing nor’easter starting to move up the coast on Sunday night, with precipitation moving into the Boston area between midnight and 3 AM EST on Monday. Again, I want to reiterate that this is still close to a week away and that things will change between now and them, so I will be posting further updates as I gain confidence in the forecasts. I’ll leave you with the ECMWF model forecast for 7 AM EST on Monday, Feb. 10th, which reinforces the setup screaming “Big Time Coastal Storm.”

ECMWF Forecast – 7 AM EST Monday, Feb 10th

I will be posting forecasts for Oklahoma later this week as this storm approaches.

The post A Look at the East Coast Weather for the Next Week appeared first on Matthew Gove Blog.