December 31, 2022

New Year's Winter Storm Threatens Blowing Snow, Severe Storms, Significant Warmth


A developing winter storm will tick almost every box on the hazards checklist to start the first week of the new year as a low-pressure system strengthens over the center of the country.

The system is over California right now, bringing plenty of much-needed rain to lower elevations and very heavy snowfall to the mountains. This low will traverse the Rockies this weekend, eventually emerging over the Plains on Monday as a fast-developing Colorado low.

We'll see widespread winter weather across northern sections of the Rockies and the Plains through Tuesday, with several feet of snow falling at the peaks and a decent, shovelable snowfall for areas like Denver, Boulder, and Cheyenne. Freezing rain and sleet are possible closer to the track of the low.

Snow and a wintry mix will continue into the Upper Midwest as the storm peaks in strength as it pushes into the Great Lakes on Tuesday.


Southerly winds pulling into the storm will drag warm, humid air deep into Canada as the low strengthens and moves through, bringing very warm temperatures to just about everyone in the eastern half of the U.S.

The calendar may say January, but the thermometer is going to scream April. Tuesday's highs will climb into the 70s as far north as West Virginia, with 60s reaching western New York—still buried under many feet of snow from last week's blizzards.

A few inches of rain could fall through early next week with this system. The rapid warmup and arrival of heavy rain could lead to flooding in areas where the ground is frozen or there's still significant snowpack from last week's storm and lake-effect bonanza.


Farther south, the system's cold front plowing into that warm and humid airmass will trigger a round of severe thunderstorms across the Deep South on Monday.

The greatest threat appears centered on the Arklatex region, with the threat stretching out to include Little Rock and Shreveport. These areas could see the threat for "potentially significant damaging gusts and a couple of strong tornadoes," the Storm Prediction Center said on Saturday.


Colder air will move in for a couple of days behind the system, but it's not going to last too long or get too cold. In fact, winter's deepest chill seems like it wants to chill out on the northern Plains for the next couple of weeks, sparing the rest of us with milder conditions through the first half of the month. (And even there it'll be warmer than normal.)

The Climate Prediction Center's latest outlook through January 13th tells the tale—decent odds of warmer-than-normal temperatures for almost everyone. Ahh, winter.

[Top Map: NOAA/WPC]


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December 21, 2022

What You Need To Know About This Dangerous Pre-Christmas Cold Snap & Snowstorm


It's pouring out of the northern Plains like an avalanche.

The temperature in Wheatland, Wyoming, on Wednesday dropped from 45°F at 9:50 a.m. local time to just 6°F by 10:30 a.m., falling further to -6°F by 12:50 p.m.

This week's remarkable crush of Arctic air will pick up speed as it hurtles toward the eastern two-thirds of the United States over the next couple of days.

Our cold front will race down the Plains through Thursday, the slug of frigid air curving eastward as a low-pressure system develops over the Midwest.
The WPC's forecast for the morning of Friday, December 23rd.


This low will slingshot the cold toward the eastern states on Thursday and into Friday morning, bitter air riding in on southwesterly winds for many folks courtesy of the vigorous flow spiraling around the center of the storm.

Many folks across the east will see Friday's high temperature happen either at midnight or during the early morning hours. This cold front will pack a punch all the way to the Atlantic, sending temperatures plummeting dozens of degrees in a matter of minutes.

The arrival of dangerous, life-threatening cold doesn't even begin to touch this pre-Christmas storm's other hazards.

Cold Temperatures

Extreme cold is nothing to scoff at. A cold snap like this can injure or kill hundreds of people through frostbite and hypothermia.

The same elderly, poor, unhoused, or chronically ill people who struggle through extreme summertime heat are vulnerable to frigid cold snaps like the one descending on the U.S. this week.


A vast swath of the country will face several straight days of subzero—and, for even more, subfreezing—temperatures heading into the Christmas weekend. That's cold for anyone no matter how acclimated you are to winter weather.

Unprotected skin can begin to freeze in as little as 30 minutes when temperatures or wind chill values dip below zero. Frostbite is possible in a short while with readings in the double-digits below zero.

Frigid temperatures will easily reach the Gulf Coast over the next couple of days, with morning low temperatures into the lower 20s spreading over the Florida Panhandle. Temperatures below freezing will reach the Orlando metro area, and Miami is expecting a chilly low temperature of 47°F by Christmas morning.


Wind chills will be even colder. Widespread wind chill warnings blanket the country from the Canadian to the Mexican borders.

No matter how much people fake-knowingly snicker at the idea, the wind chill isn't made up.

Scientists developed the wind chill by studying how cold temperatures and wind affect the human body. Gusty winds on a frigid day chill your skin faster than your body would otherwise lose heat if it wasn't windy out. A wind chill of -15°F means that the combination of cold air and gusty winds has the same effect on your body as an actual air temperature of -15°F.

Take this cold snap seriously. Cold air is bad enough, but it'll be life-threatening for much of the country when you factor in the winds.

Flash Freeze

Most folks are going to see rain before the cold front roars overhead and temperatures plunge below freezing. Those wet roads and sidewalks won't have a chance to dry off before the frigid air arrives, leading to a dangerous and widespread risk for a flash freeze.

We're used to dealing with patches of black ice during the winter months, but a flash freeze is like if everything turned into black ice. A flash freeze on a major highway can cause significant pileup accidents.

If you're travelling or heading home from work or school over the next couple of days, make sure you're where you need to be once the cold temperatures hit—otherwise, you might get stuck wherever you are for a while.

Blizzard Conditions

Areas where precipitation follows the arrival cold temperatures will see heavy snow.


The heaviest snow will fall across the Great Lakes where the extreme temperature gradient between the relatively warm water and bitterly cold air will allow the lake-effect snow machine to crank at full capacity, especially off of Superior and Michigan.

Several inches of snow are possible across a widespread area from the central Plains toward the Northeast. It's not going to be a blockbuster snowstorm away from the Lakes, but the very cold temperatures will make this a fine, powdery snow—perfect for blowing around.

Very strong winds will develop as the cold air floods in and the accompanying low-pressure system strengthens over the Great Lakes. Even if you're only expecting a few inches of snow from this system, the powdery snow will easily blow around in the blustery winds, leading to whiteout or near-whiteout conditions for a very large area.

NWS wind gust forecast for 10:00 a.m. EST on Friday, Dec. 23, in knots. (For reference, 30 knots is about 35 mph, and 40 knots is 46 mph.)

It's likely that driving will be nearly impossible at times throughout the central U.S. heading into this weekend. If you can avoid it, don't go driving anywhere when it's snowing. You really, really, really don't want to get stuck on an impassable highway when temperatures are near or below zero.

It's likely that the snow and winds will cause widespread delays and cancellations at the region's major airports, including Chicago, Detroit, Pittsburgh, and Toronto. Bad weather affecting major hubs around a holiday is a recipe for hundreds (if not thousands) of delayed or cancelled flights.

Anticipate having to make alternate arrangements in a hurry, even if you're not flying through the affected areas. All planes have to come from somewhere, and if your plane gets stuck up the line at a snowed-in hub, you're not flying anywhere anytime soon.

Beware The Risk For Power Outages

The same high winds that will lead to dangerously cold wind chills and blizzard conditions could also lead to power outages. There aren't really any good times for the power to go out, but the power going out during a life-threatening cold snap is exceptionally bad.

Make sure you've got enough to eat, flashlights to feel around at night, rechargeable battery packs for cell phones, and plenty of blankets just in case the high winds (or demand on the grid) cause power outages.


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December 18, 2022

100+°F Temperature Gradient Likely As Extreme Pre-Christmas Cold Snap Hits U.S.


You know it's going to be a heck of a cold front when there's a 99-degree temperature difference between Glasgow, Montana, and Miami, Florida, in the middle of the day.

A brutal blast of Arctic air will pour south out of Canada this week and plunge almost all of the eastern two-thirds of the United States into an extended cold snap.

That Glasgow-Miami difference isn't even the worst of it. It's likely that we'll see a >100°F spread between the warmest high temperature and the coldest high temperature in the U.S. at some point on Thursday or Friday.

Temperatures won't climb much above the single digits, let alone the freezing mark, over a vast swath of the country for a couple of days this week.

The P***r V****x

This pre-Christmas cold spell comes courtesy of a splintered piece of the polar vortex—that terrifying, mythical wintertime creature that lurks in the "favorites" list of every broadcast news computer's scary graphics folder.

The polar vortex is an ever-present belt of winds that wraps around the North Pole, growing to its peak strength every winter. This circulation keeps winter's coldest air confined to the Arctic when it's strong and well-behaved.

SOURCE: Tropical Tidbits

However, the circulation becomes unstable from time to time, allowing troughs or upper-level lows to swoop down to lower latitudes. These "pieces" of the polar vortex bring bitterly cold air south with them. 

Our looming surge of Arctic air will come courtesy of an upper-level low that was once a part of the polar vortex's broader circulation over far northern Canada.

Not only will this low pull frigid air as far south as Florida and southern Texas, but this setup will generate a low-pressure system at the surface.

This developing late-week storm will bring a major bout of wind and wintry precipitation just in time to mess up everyone's holiday travel plans across the Midwest, Great Lakes, and Northeast.

The Cold

Subzero temperatures were firmly locked in place across the northern Plains on Sunday night, and temperatures will remain in negative territory for a full week from the northern Rockies to the Upper Midwest.

Wind chill values will drop well below -40°F during the worst of the cold across this region. That's dangerous cold even for the hardiest Plains resident who boasts about their fortitude. Actual air temperatures below -30°F, and wind chill values below -40°F, can lead to frostbite and hypothermia in a matter of minutes. It's serious stuff.


This unpleasantly cold air will steadily march southward over the next couple of days, forcing daytime highs to remain well below the freezing mark—even into the single digits or below zero—as we head through the middle of the week.

Thursday will see the most extreme temperature gradient across the country as our big storm system begins to develop across the Midwest.

Miami will bask in a high of 81°F on Thursday afternoon, while Glasgow, Montana, will only hit a balmy -18°F.


Overnight lows into Friday morning will be downright rude, with -30s widespread in the Dakotas, subzero readings into Oklahoma, and single digits as far south as northern Mississippi and Texas' Big Bend region.

It'll finally take until the night before Christmas for the cold front to reach the Atlantic coast, and all through the country it'll be...really darn cold.


Temperatures will dip into the 40s down in the Everglades, and lows on Christmas morning will even get into the lower 20s across the northern Gulf Coast. (22°F is frigid for Mobile, Alabama, y'all.)

Conditions will gradually improve and warm toward some semblance of normal during that vaporwave week between Christmas and New Year's when existence is a simulation and nobody actually gets anything done except for eating cookies and reading best-of-2022 listicles.

The Storm

Ohhh, the storm.

You've probably heard about it on Facebook or Mastodon or the failing tweeting bird app in the past week:

"It's a blizzard. It'll be a behemoth. It'll rival your grandparents' best childhood memories."

It's going to be a doozy for somebody, for sure. If you live along the East Coast, though...it's probably not gonna be you.

SOURCE: NWS/WPC

Models this weekend came into a bit of agreement that this low will track along or west of the Appalachian Mountains, which is great news for snow lovers in the Midwest and Great Lakes, and a nightmare scenario for the same group of folks along the I-95 corridor.

It's still too early to call out specifics like snow totals, ice accretions, or even which cities are going to get walloped the hardest. (It's at least four days away. For real. C'mon.) But the signals are all there that this is likely going to be a high-impact event for lots of major cities, including Chicago, Detroit, and Toronto.

Forecasters are already starting to use phrases like "blizzard conditions" for some areas, so this storm—regardless of its precise track—will have significant impacts on cross-country travelers heading out by road, rail, or plane.

Keep in mind that foul weather at air traffic hubs will have downstream ripple effects that affect flights that won't ever touch a snowy runway. (Every plane comes from somewhere else, after all.)

We'll have a better idea of what that storm will look like as we make our way through the week. Models will jump back and forth with its location a bit. Remember that only a few dozen miles to the east or to the west can have huge implications for the impacts of a winter storm.

The best thing to do now is to make flexible travel plans (a polite way of putting it) and try keep a jolly demeanor about whatever blows our way. We'll remember this ordeal fondly come July when we're breaking all-time heat records again.

[Top image created using WSV3.]


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December 12, 2022

Major Storm Threatens Blizzard, Ice Storm, Tornadoes, Heavy Rain...You Name It


The first real rip-roarin' winter storm of the season is cranking up over the Plains states this evening.

The storm will kick into high gear heading into Tuesday, bringing blizzard conditions and a full-on ice storm to parts of the High Plains, while folks across parts of the south have to deal with the risk for severe thunderstorms and tornadoes.

A fast-developing low over northeastern Colorado will strengthen over the next 12-24 hours as a strong jet stream moves across the Rockies.

This large system will have a little bit of everything for everyone—it'll be one of those classic winter storms that puts on a gorgeous curly display when we gawk at satellite imagery on Tuesday and Wednesday.

The northern side of the storm will have plenty of cold air for heavy snow and freezing rain to fall over the northern Plains.

Forecasters expect the worst conditions to cover communities from northeastern Colorado into the Dakotas.


It's not heavily populated terrain by any means, but it'll be a disruptive storm for folks who live in the area, and it'll make life difficult for cross-country travelers by road and rail.

The latest forecast from the National Weather Service calls for widespread totals of more than a foot of snow across the hardest-hit areas, with more than two feet of snow possible for some (un)lucky towns, especially in South Dakota.

Closer to the track of the low itself, warm air nosing its way into the lower-levels of the atmosphere will lead to a prolonged freezing rain event.

An ice storm warning is in effect for parts of eastern South Dakota, including Brookings, for the potential for 0.25 to 0.50 inches of ice accretion. That's more than enough solid ice to bring down tree limbs and power lines.


A solid stream of warm, moist air pumping north from the Gulf will fuel a widespread risk for severe thunderstorms through midweek. The greatest risk will play out on Tuesday, with the Storm Prediction Center issuing an enhanced risk for severe weather (a 3 on the 1-5 scale) centered on much of Louisiana.

The biggest concern with Tuesday's storms will be the risk for tornadoes. The environment may be capable of producing significant, long-track tornadoes. If you're in or near the region at greatest risk, keep an ear out for severe thunderstorm and tornado warnings and have safe shelter nearby you can reach in a hurry.


Snow, ice, and tornadoes aren't this storm's only risks. We're looking at the risk for several inches of rain across the southeastern states over the next couple of days. This steady march of heavy rain will beef up the potential for flash flooding in vulnerable areas.

This storm will spin itself out (to use the technical term) by Thursday, with its remnant moisture going on to feed the development of another system along the East Coast by the end of the week.


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