All Weather News

What A Difference A Day Makes!

12 Jan 2013, 2:49 pm

Cold air is retaking the national map, where warm air was sitting comfortably for a portion of January.  Like my skinny companion above, the warm air is getting lifted up and out of here!  (from suppversity.blogspot.com)

Portions of the midwest have had to experience an incredible change in temperatures in the past 24 hours.  So how do we go from unseasonably warm, un-January-like, weather, to blizzard conditions?  Well lets see whats going on in the atmosphere.

The jetstream is making moves this week, with a dip forming over the western portion of the country and a ridge building in the east.  The jetstream is the atmospheric river of narrow, concentrated winds that helps steer the weather patterns across the country, and the world.  It lies high up in the atmosphere, and its position will vary from day to day, but sometimes, it can slow down over a region.  Here is the position of the jetstream this week.  Notice it is allowing COLD air to descend down towards the Mexico border, while on the other side of the jet, a warm flow of Gulf Moisture is being sent up towards the eastern half of the nation, from an area of High pressure.  Earlier in the week, the jet’s dip was smaller and further out west and now, it is spreading towards the east coast, and bringing the cold, Canadian air with it.

Ahead of the storm system, that is riding along the jetstream and going towards the Great Lakes, warm, moist air was being pumped up into portions of the midwest.  There was a foggy sight out in some areas of Iowa yesterday, so much so, that Dense Fog Advisories were needed to be put up.  Temperatures in Des Moines were at 53° around midnight, and then cold front passed and temperatures went into a free-fall!  By the morning hours, the temps were down into the 20s.  The average high for Des Moines for January 11th is 31° and they almost tied the record of the day of 55° set back in 2005.

Over in North Dakota, there was blowing snow coming in from the storm system.  Temperatures were dropping like rocks into a river and gusty winds made it feel below zero for many areas.  Out in Bowdon, ND, there were blizzard conditions, and with the flat, open lands, the winds could blow the snow around easily, leading to the low visibility issues.

In the Twin Cities, there was also a temperature drop, but without much in terms of snow.  There were light, spotty batches of snow coming down, but just enough to coat some road ways with a thin layer.  On Friday, temps were not warm enough to support snow, with a high of 41° (record was 44° set back in 1986) that occurred before midnight.  But throughout the overnight hours, the temps went way down, into the teens, a drop of nearly 30°!And if you were walking around the Twin Cities, MN metro area, it would feel blustery!  As of mid-day, the wind chill was down into negative territory.  Make sure to bundle up.

The cold air continues to move down and out from the west, and head towards the east like a massive wave.  Temps in the Twin Cities, as of 2 PM EST, dropped about 22° from where they were at the same time on Friday.  And there was a shocking drop of over 50° in 26 hours in Alamosa, CO!  At 3 AM on Friday, temps were at 25° and by 6 AM Saturday, they were down to -25°…. I can’t even fathom what that was like to be there, and image if you were outside in the wind chill, OUCH!

Here I’ll lay out the advancing cold air scenario across the nation for today and tomorrow.  If you are out on the east coast, enjoy the warmth, for sure, it will be gone.

Take care everyone, stay warm (if you are in a cold portion of the nation), or go out and enjoy the weekend (if you are in a warm portion of the nation).

Meteorologist Addison Green (Twitter @agreenWNTV)

 

 

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