12/17/14: Mostly Cold

A ridge of high pressure was extending from eastern Manitoba all the way into northern Missouri this morning.   That would place eastern North Dakota and northwestern Minnesota within this ridge which was powerful enough to clear the sky.

7:00 AM Surface Analysis
7:00 AM Surface Analysis

With the clear sky and light wind associated with the high pressure ridge temperatures dropped around 0° with the coldest reading of -7° F recorded at the Rolla, NDAWN station.

12/17/14 Minimums
12/17/14 Minimums

Western North Dakota recorded minimums were much higher because, you guessed it, because of cloud cover.  The low stratus and fog that has plagued the region in the past week has returned to western North Dakota.  In many ways this is associated with the wind turning to the south or southeast in that area advecting low level moisture into the colder air mass.

8:15 AM Wind Speed and Directions
8:15 AM Wind Speed and Directions

The darker line in central North Dakota on the image below is the cloud deck that extends into South Dakota as well.  Those low clouds will probably move easterly, but the process will be very slow.  So as a general rule if it is sunny this morning, it will probably stay sunny today in your area, if it is cloudy, the clouds will likely stay.

Morning Satellite
Morning Satellite

 

As the wind transitions to the south, a warm up is expected with temperatures near freezing expected this weekend.  The expected cloud cover associated with this warm up should mean very mild overnight lows.  The main threat of precipitation will come early next week.  The lower clouds tend to always bring some drizzle or very light snow / flurries but otherwise, it will be early next week for the return of snow and perhaps the one main chance of recording a white Christmas in 2014.   It is after that event that cold arctic air is expected to return.  How cold it will get will be to some degree determined by the amount of snowfall on the ground.  At the moment odds favor a minimal snow pack meaning the cold coming will probably be below average, but not an extreme cold by our standards.

Daryl Ritchison