DES MOINES, Iowa -- As a record setting and likely once-in-a-generation, if not once-in-a-lifetime arctic air mass settles in over the upper Midwest, some forecasters are really pulling out all the stops to communicate how dangerous the event is -- even to hearty Midwesterners who know a thing or two about below zero temperatures.
In Chicago, where spray off Lake Michigan routinely freezes on impact in the winter, some of their all-time cold records are in jeopardy. They've never reported a temperature colder than -27 nor had a day where the temperature didn't at least get to -11; both numbers are in jeopardy this week. Wind chills? Expected in the -45 range.
Down in Iowa, forecasters are really hoping people don't chalk up this cold streak to a typical winter blast.
"This is the coldest air many of us will have ever experienced," forecasters for the National Weather Service in Des Moines wrote Tuesday morning. "It's not a case of 'meh, it`s Iowa during winter and this cold happens.' These are record-breaking cold air temperatures, with wind chill values not seen in the 21st century in Iowa."
Aside from making sure all cars have plenty of fuel and blankets and any exposed skin is covered with multiple layers, forecasters are warning even to keep your mouth shut.
"Make sure your mouth is covered to protect your lungs from severely cold air," forecasters wrote. "Avoid taking deep breaths; minimize talking."
"In summary, please be smart and take care of one another."
Some forecasts for northeastern Iowa have wind chills as low as -60! It's tough to fathom how you could literally make it feel 55 degrees warmer outside -- and still be below zero!
But that's exactly where their forecast is going in an incredible bout of weather whiplash. Once the artic blast eases past Thursday, temperatures will rapidly warm some 60-70 degrees! Chicago is looking at a high in the low-mid 40s on Sunday -- that's above zero, by the way -- with... rain! It will come 72 hours after temperatures were more than 20 degrees below zero. Amazing!
The arctic air is courtesy of a Polar Vortex -- when the jet stream weakens around the North Pole, allowing the arctic air usually bottled up at the pole to sink south across Canada into the Midwest -- almost like a dam holding the cold air back breaking.
Once their see-saw from record cold to Seattle-esque winter rains pass this weekend, long range forecasts show more typical winter conditions of highs in the 20s with occasional snow.