1/12/15: A Clipper and More Cold

The upper level wind flow this morning is coming in from the northwest.   This is expected to be the case for several more days.  Often in a northwest flow regime the area will get a series of “Alberta Clippers” passing through the region.  A very weak disturbance brought a dusting of snow to the area  yesterday into last evening, but a stronger disturbance will pass through the northwest flow on Thursday.

6:00 AM Initialize 200 mb (Jetstream) wind direction and speed over USA.
6:00 AM Initialize 200 mb (Jetstream) wind direction and speed over USA.

 

On Thursday, a well organized area of low pressure will move out of the Prairie Provinces of Canada and move quickly southeast through southwestern North Dakota to northern Iowa.

6:00 AM Thursday, Projected Surface Conditions with precipitation (snow)
6:00 AM Thursday, Projected Surface Conditions with precipitation (snow)

 

This would typically spread snow across northern and eastern North Dakota, down toward the Twin Cities and Wisconsin.  Although moisture content looks low, it tends to take very little moisture in colder temperatures to generate a couple of inches of snow.  At this time it appears that one to three inches of snow will fall from Williston to Fargo and points northward.  Probably fluffy.  Behind the snow will be several hours of enough wind for some blow and especially drifting snow.  That wind will bring in the arctic air once again and set the area of from a frigid weekend.

There will be a secondary surge of cold air on Friday into Friday night as a cold front reinforces the cold air that will already be in place.  This will bring with it gusty northwest wind and perhaps a dusting of snow along the front.  This will bring more blowing and drifting snow to the region on Friday.

cold front
Friday 6:00 PM Surface Projection

 

Temperatures in the -10s should be widespread, with -20s and a few -30° temperatures foreseen where there is a deeper snow cover.  Warmer conditions will come back next week, especially from Wednesday through the following weekend, but in the short term.  We still have a solid week of well below average temperatures for the region.

Daryl Ritchison