1. Beautiful animation depicts brutally cold air blasting much of nation
The animation shows 48 hours of predicted temperatures across the United States starting Wednesday afternoon. One might mistake it as a beautiful work of art, if it weren’t for the real-life ramifications of the brutal blast of cold air.
That forecast, with the purples and whites representing temperatures as much as 30 to 50 degrees below normal, has already come to fruition for much of the Northern Plains, where temperatures on Thursday dropped to minus-10 to minus-30. The teens and single digits made it as far south as the northern half of Texas as of midday Thursday.
If you’re thinking it looks like the coldest air (white and purple) could be coming due south from Siberia, you’re right!
2. Upside-down temperatures have Oklahoma colder than Alaska
At midday Thursday, the Arctic blast was making its mark with single-digit temperatures as far south as Oklahoma. As a result, Oklahoma City was 13 degrees colder than Utqiagvik, Alaska’s northernmost city, as shown above. Factoring in the wind, Oklahoma City felt like minus-22 compared to a wind chill of 5 in Utqiagvik.
All should be right in the world again by Friday when Oklahoma City is forecast to reach a relatively balmy high of 19 while Utqiagvik may only manage a high of 4.
3. Apparently it will be very cold, according to the ‘apparent temperature’ forecast
This “apparent temperature” forecast from the National Weather Service, or what you and I call the wind chill, shows how cold the air is expected to feel on Friday at 7 a.m. Below-zero wind chills are predicted for an incredibly large chunk of the nation, ranging from minus-30 to minus-50 across the Northern Plains and much of the Midwest, to minus-20 to minus-30 across the Central Plains, to zero to minus-10 as far south as Central Texas and the northern parts of Louisiana, Alabama, Mississippi and Georgia.
By Friday night into Saturday morning, wind chills near zero to minus-20 are forecast to reach the Mid-Atlantic and Northeast, with single digits and teens along the Gulf and Southeast coasts.
At such extreme wind chills, frostbite can occur within minutes.
4. Watch the subzero wind chills march to the east
Just as impressive as the low wind chill values is how quickly the wind-chilled air is marching from west to east across the country. In this zoomed in view of the National Weather Service’s high-resolution NAM model, you can see just how fast the cold air is forecast to advance eastward, and just how tight the gradient is between relatively warmer air ahead of the front and dangerously cold wind chills behind the front.
We already saw just how quickly this Arctic front is capable of dropping temperatures in places like Casper, Wyo., where the temperature on Wednesday went from 27 to 3 in just 15 minutes as the front came through, and fell by 70 degrees in less than 24 hours, with the wind chill plummeting to minus-65. On Wednesday, Denver saw its temperature drop a record 37 degrees in one hour and its wind chill dropped to minus-40 Thursday morning.
5. Monster winds to create massive waves on Great Lakes
Massive waves are predicted for Lake Superior, peaking late Friday through Saturday, according to this experimental wave model operated by the Great Lakes Environmental Research Laboratory of the National Oceanic and Atmospheric Administration. As winds from the northwest gust 50 to 60 mph or even a bit higher from midday Friday into early Sunday, the water is expected to pile up into waves of 20 feet or higher across the southeast portion of the lake.
With temperatures in the single digits and teens, a heavy freezing spray warning is in effect late Thursday night through late Friday night for central, eastern, and western portions of Lake Superior. “Freezing spray at a rate of 2 cm per hour or greater expected, and may rapidly accumulate on vessels,” according to the National Weather Service.
High waves are forecast for some of the other Great Lakes as well as shown below.
6. Bomb cyclone likely as storm pushes east
Low pressure will rapidly intensify along the Arctic front, probably meeting the criteria for a “bomb cyclone,” which requires at least a 24-millibar pressure fall in 24 hours. The animation is a forecast from the European model, which predicts the storm’s pressure will drop from 1005 millibars over Indiana to 961 millibars over southern Quebec.
Generally speaking, the more rapidly a storm’s pressure falls, the more extreme the weather it creates. In this case, the amount of precipitation won’t be as extreme as we have seen with some other bomb cyclones. It is the speed and intensity of the Arctic air that the storm will help drive southward that is so impressive as well as the gusty winds.