12/14/15: Snow a Comin’

After being away for a while, finally, I’m back in the office for a weather update.  After a very mild first one-half of December, colder air will be arriving this week, especially after some the expected midweek snow leaves the area white once again.  This morning there is a strong area of low pressure in northeast Iowa that was unable to tap into enough cold air to produce much snow, but instead a widespread rain event with just a smaller area of snow on the far back side of the storm.

6:00 AM Surface Analysis

6:00 AM Surface Analysis

Rainfall amount in excess of one inch has been recorded with this snow, so the snow amounts could have been high and widespread, but instead were still significant, but very localized especially in Kansas into parts of Iowa.

Projected Monday Radar

Projected Monday Radar

Immediately following this first storm, will come a second low pressure center, but this one will track much farther to the northwest.   The next storm should be near Lincoln, NE by 6:00 PM Tuesday, December 15.  That will mean snow for much of South Dakota developing during the afternoon hours that day and will arrive in North Dakota Tuesday evening.

Tuesday, December 15, 2015 Projected Surface map and Precipitation (type)

Tuesday, December 15, 2015 Projected Surface map and Precipitation (type)

 

That storm will continue to push to the northeast and be near Willmar, MN by noon on Wednesday and then move out of the area into Canada on Thursday.

Wednesday, December 16, 2015 Projected Surface Map and Precipitation (type)

Wednesday, December 16, 2015 Projected Surface Map and Precipitation (type)

Unlike the last storm of similar magnitude on November 30 and December 1, once the low pressure center moves into Ontario, much colder air will move into the region.  That process will begin on Wednesday, but be in full force on Thursday.

Projected Thursday, December 17, 2015 6:00 AM Surface Map and Precipitation (type)

Projected Thursday, December 17, 2015 6:00 AM Surface Map and Precipitation (type)

 

With a fresh snow pack (3 to 6 inches with localized higher amounts), temperatures are expected to drop to the single digits below and above 0 on both Friday and Saturday morning.  Below is a projected on Friday AM minimums from the GFS (Global Forecast System) but if the sky stays clear, I would not be surprised if temperatures are colder than what is presented on the graphic.

Friday (December 18, 2015) projected AM Minimums

Friday (December 18, 2015) projected AM Minimums

Beyond Friday and Saturday, temperatures will gradually rebound and may end up above average again next week for a few days, but only slightly so, no well above freezing temperatures are projected meaning almost all areas that record snow this week, will end up with a white Christmas this year.

Next storm beyond the one in the next 72 hours may occur sometime around Christmas.  That of course doesn’t mean every spot will record rain, it is just there are some indications that the north central part of the lower 48 states look at this time to be impact by another low pressure center.  Obviously, any details this far out our lacking.

Daryl Ritchison

 

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