12/5/14: The Weekend and Beyond

A very weak wind shift line, that probably went unnoticed for most moved through North Dakota yesterday into the overnight hours.  There were a few sprinkles or snow or sleet associated with this wind shift but otherwise, the main effect will be today will be slightly cooler than yesterday, especially in southern and western North Dakota that recorded temperatures a bit warmer than other parts of the state on Thursday.

 

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

 

Today looks sunny with highs mostly in the 20s, the wind northwest 10-20 mph.  A bit brisk, but pretty typical for early December.  Tomorrow also looks dry, with similar temperatures to today, but with a lighter wind.  On Sunday an area of low pressure will move near the US / Canadian border.  That will bring at least the threat of some precipitation into North Dakota and northern Minnesota.  Because that clipper will be moving to the north of the area, most of North Dakota will be in the warm sector of the low, meaning, warmer temperatures, not only at the surface, but also aloft.

Projected Surface and Precipitation at Noon Sunday, December 7, 2014 (GFS)
Projected Surface and Precipitation at Noon Sunday, December 7, 2014 (GFS)

 

Temperatures a few thousand feet above the ground should be above freezing, meaning that any precipitation that does fall on Sunday, albeit light, could be mixed with rain, sleet or graupel.  Once that low moves east of the area on Sunday night, then cooler air from Canada will once again advect into the northern plains and upper Midwest, meaning a cooler Monday after many locations record highs in the 30s on Sunday.

But the cool down for Monday looks short-lived as beginning Tuesday and perhaps lasting the entirety of next week will come a significant warm up.  There will be a strong upper-level low developing in the Gulf of Alaska which in turn will build a ridge over the western and central portion of the United States.  With the main jet stream moving across southern Canada, mild Pacific air should in turn move into North Dakota and bring some mild conditions that will last several days.

500 mb Heights and wind for Thursday December 11
500 mb Heights and wind for Thursday December 11

 

Conservatively, highs in the 30s should be very common with some 40s in locations with little or no snow cover.  Little if any precipitation is foreseen during that stretch and at the moment, the earliest I would foreseen any moisture of consequence may be next weekend around the December 15-17th time frame.

As much of North America catches a break from the cold air that has dominated for nearly a month, much of Russia will be quite cold, even by their standards for the time of year.  The cold will more than likely eventually get dislodged and impact North American eventually, timing to me appears to be the holidays or early 2015.

Minimum Temperatures in northern Asia on Wednesday, December 10, 2014
Minimum Temperatures in northern Asia on Wednesday, December 10, 2014

 

Enjoy the ride.

 

Daryl Ritchison