The winter storm forecast in 6 maps, from arctic blasts to bomb cyclones

1. A beautiful animation depicts brutally cold air blasting across much of the nation

The animation shows 48 hours of forecast temperatures across the United States as of Wednesday afternoon. One could mistake it for a beautiful piece of art if it weren’t for the real effects of the brutal blast of cold air.

That forecast, with purple and white representing temperatures 30 to 50 degrees below normal, has already come true for much of the Northern Plains, where temperatures plunged to minus-10 to minus-30 on Thursday. The teens and single digits had made it south to the northern half of Texas by midday Thursday.

If you think it looks like the coldest air (white and purple) might be coming south of Siberia, you’re right!

2. Inverted temperatures make Oklahoma colder than Alaska

By midday Thursday, the arctic blast had left its mark with temperatures in the single digits as far south as Oklahoma. As a result, Oklahoma City was 13 degrees colder than Utqiagvik, Alaska’s northernmost town, as shown above. Taking the wind into account, Oklahoma City felt like minus -22 compared to a wind chill of 5 in Utkiagvik.

All should be right with the world again by Friday, when Oklahoma City is projected to reach a relatively mild peak of 19, while Utqiagvik can only manage a peak of 4.

3. Apparently it will be very cold according to the visible temperature forecast

This National Weather Service “apparent temperature” forecast, or what you and I call a wind chill, shows how cold the air is expected to be on Friday at 7am. Below-zero wind chills are forecast for an incredibly large swath of the nation, ranging from minus-30 to minus-50 in the Northern Plains and much of the Midwest, to minus-20 to minus-30 in the Central Plains, to zero to minus-10 as far south as Central Texas and northern parts of Louisiana, Alabama, Mississippi, and Georgia.

Friday night into Saturday morning, wind chills of zero to minus-20 are expected to reach the Mid-Atlantic and Northeast, with single digits and teenagers along the Gulf and Southeast coasts.

In such extreme cold winds, frostbite can occur in minutes.

4. Watch the freezing cold winds blow east

Just as impressive as low wind chill values is how quickly wind-cooled air spreads from west to east across the country. In this zoom view of the National Weather Service’s high-resolution NAM model, you can see how quickly the cold air is forecast to advance eastward and how narrow the gradient is between relatively warmer air ahead of the front and dangerously cold wind chill behind the front .

We’ve already seen how quickly this arctic front is capable of dropping temperatures in places like Casper, Wyo., where Wednesday’s temperature went from 27 to 3 in just 15 minutes as the front passed, dropping 70 degrees in less than 24 hours. with the wind chill dropping to minus -65. On Wednesday, the temperature in Denver dropped a record 37 degrees in one hour, and the wind chill dropped to minus -40 on Thursday morning.

5. Monster winds to create massive waves on the Great Lakes

Massive waves are forecast for Lake Superior, peaking Friday through Saturday, according to this experimental wave model run by the National Oceanic and Atmospheric Administration’s Great Lakes Environmental Research Laboratory. With winds out of the northwest gusting 50 to 60 mph or even slightly higher from midday Friday through early Sunday, water is expected to pile up in waves of 20 feet or higher on the southeast side of the lake .

With temperatures in the single digits and in the twenties, a hard freeze warning is in effect Thursday night through late Friday night for central, eastern and western parts of Lake Superior. “Freezing spray at 2 cm per hour or more is expected and can quickly accumulate on vessels,” According to The National Weather Service.

High waves are forecast for some of the other Great Lakes, as shown below.

6. A probable bomb cyclone as the storm pushes eastward

Low pressure will quickly strengthen over the Arctic front, possibly meeting the criteria for a “bomb cyclone”, which requires a pressure drop of at least 24 millibars in 24 hours. The animation is a forecast from the European model, which predicts the storm’s pressure will drop from 1,005 millibars over Indiana to 961 millibars over southern Quebec.

Generally speaking, the faster a storm’s pressure drops, the more extreme the weather it produces. In this case, the amount of rainfall will not be as extreme as we have seen in some other bomb cyclones. So impressive are the speed and intensity of the arctic air the storm will help push south, as well as the gusty winds.