A “sudden freeze” can accompany this storm, as temperatures drop as quickly as one degree per hour, quickly freezing any rain or melting snow that remains on the ground.
An “instant freeze” occurs when temperatures dropping rapidly “quickly turn any wet or muddy road into ice,” noted the Des Moines National Weather Service, warning that it is likely to create significant travel problems across the state of Hawkeye on Thursday. market.
Arctic cold will not spare the rest of the country, either. On Monday morning, 235 million Americans, or about 86% of the country, will experience sub-zero temperatures. This includes all Lower 48 states.
Blizzard sets the stage for extreme cold
Strong winds, blowing snow and rapidly falling temperatures are expected until Friday from Nebraska to Michigan.
Blizzard warnings are in effect in central and northern Iowa until Friday morning, while winter storm warnings and alerts extend further east to Chicago and Grand Rapids.
The criteria for blizzard conditions do not necessarily require snow to fall from the sky.
As with this storm, only moderate accumulations are forecast, ranging from 5-5 inches in Des Moines and up to 8 inches in Green Bay. Higher totals can be expected downwind from Lake Michigan in the favored Lake Effect areas. , where up to a foot of snow is possible.
Ahead of the system, a winter mix of rain and snow is predicted as temperatures rise briefly before drastically falling behind the cold front.
Winds are forecast for gusts of more than 45 miles per hour, blowing snow and reducing visibility below 400 meters in parts of Iowa. As mercury falls and snow begins to fall on roads, conditions deteriorate at any time.
Waterloo, Mason City and Fort Dodge are expected to experience “extreme” travel impacts from this powerful storm, according to the NWS risk matrix.
Even with blizzard warnings in place, high snow totals will not be the biggest threat from this storm. The real stumbling block will be cold air settling in early next week.
A flash froze to hit the Midwest
The cooler air will begin to plunge south through the upper midwest and the Great Lakes on Saturday. Locals in central Wisconsin can see temperatures plummet to -25F on Sunday morning, with high temperatures struggling to zero. Nighttime casualties can be cold enough for your car’s antifreeze to solidify.
“We receive two to three of these pressures each year,” said meteorologist Marcia Cronce of the National Weather Service Office. “We are entering the coldest air of the season, it will look shaken.”
St. Paul’s school districts cancel classes if the forecast for 6 am the next day is -25F or if the cold wind drops to -35F.
The polar vortex is coming
This will cause the polar vortex to weaken further, creating extremely cold conditions.
The cold trend will continue for the next 10 days.