Siberian Express: Winter’s coldest temp Friday?

Welcome to what will likely be the coldest morning of the winter Friday.

A bitterly cold arctic air mass is has invaded Minnesota, and the core of the coldest temperatures will settle in over Minnesota Friday morning.

The so called "Siberian Express" is a cross polar air flow that can deliver barbarically cold air to Minnesota from Siberia by way of the North Pole.

Temperatures plummeted to -40 near the center of the high pressure system in Saskatchewan Thursday morning, and readings may approach that number in northeast Minnesota Friday.

In the south, temperatures will bottom out in the -15 to -25 degree range. The most extreme computer model (GFS) is cranking out an air temperature of -31 at Twin Cities Airport Friday morning.

While the Urban Heat Island may prevent readings in the inner city from getting that cold, it's going to be plenty cold no matter how you slice it. I still think temperatures may plummet to -20 to -22 at Twin Cities Airport Friday morning, with -25 possible in the outer suburbs.

Skin can freeze in minutes:

We're tough Minnesotans but this is serious cold folks. Your skin doesn't care how "macho" your mindset is. At wind chills of -30, your skin can literally begin to freeze in minutes. Check out the NWS wind chill chart for the gory details.

Cold wave is brief but brutal:

While -20 to -30 is routine in a northern Minnesota winter, it's tough to reach -20 to -25 in the metro. It just doesn't happen that often. That's why this week's brief but brutal cold snap is not as common as you might think.

If we plunge to -25 in the metro, it would be the coldest air in about 15 years. The last time temperature plunged to -25 in the Twin Cities was February 2, 1996.

"Extreme Cold Warning":

The cold wave even has NWS trotting out a new experimental warning product. NWS issued an "Extreme Cold Warning" for northern Minnesota into early Friday. The new product will be used in situations where extreme cold when temperatures hit -35, regardless of any "wind chill."

Ironically, the coldest ambient air temperatures are usually reached near the center of arctic high pressure systems, where there is little wind to enhance the wind chill effect.

Clipper Friday PM:

An Alberta Clipper will follow right on the heels of the arctic cold Friday morning. Snow will spread from west to east, and could arrive in the metro later Friday morning and continue through the PM. The system should be mostly light, with snow totals around an inch or less in most locations.

Thaw next week?

Temperatures will quickly rebound into the teens this weekend, and may push 32 by next week. That's going to feel really nice when compared to Friday morning.

In the mean time, stay warm!

PH