3-15-18 Northern Plains: Latest details on snow and freezing rain accumulations for portions of the area. B.

Video (6:00):

Good Thursday morning! We’re watching some very spotty spots of sprinkles and freezing drizzle in Western South Dakota this morning, though much of what is currently on radar may not be reaching the ground given dry air in the region.

Winter Storm Warnings, Watches and Advisories are in effect for much of the southern half of South Dakota for the storm system that will bring snow and freezing rain accumulation beginning tonight. 

Precipitation increases in intensity overnight tonight and heavy rain that initially falls in southwest South Dakota will give way to very heavy snowfall tonight. Moderate to heavy snow likely falls between 3AM tonight till 2PM tomorrow before it starts to weaken and move off to the east. Other areas in southern south Dakota and as far east as southwest Minnesota will see some snow, but the system will weaken enough that major accumulations aren’t likely. The main swath of snow exits the Dakotas late tomorrow evening and exits Minnesota just after midnight tomorrow. Some scattered snow showers will linger into the morning on Saturday for portions of the Dakotas. Here’s a look at the simulated radar into Saturday. 

The NAM/European/RDPS have been consistent with their idea for snowfall. Given a lack of low-level frontal forcing, we are siding with the less aggressive NAM as of now for totals. However, some isolated totals of 12″+ cannot be ruled out given snow could fall for close to 12 hours in some spots. We believe areas in the yellow circle could certainly get 5-9″ with isolated totals of 10-12″. Currently thinking areas east of this swath see a general 1-4″ with 1″ or less for far Eastern South Dakota and Southwest Minnesota.

Note on the simulated radar, there is the chance for some freezing rain in southern and southeast South Dakota. The best chance for freezing rain accumulation will be in the morning hours between 5AM and 10AM though scattered freezing rain is still possible until 1PM, but temperatures will only be slightly above freezing at this time and there will likely be mixing with sleet before a changeover to snow for a few hours late on Friday. The big limiting factor for freezing rain will be temperatures that reach the upper 40s today. This will make pavements very warm and limit freezing rain accumulation at the initial onset of precipitation. Here’s a look at high temperatures today and our thoughts for freezing rain.

We do have a system to track late this weekend and into next week. Models have been inconsistent with their solution for this, but it does bring a chance of additional wintry weather and snow accumulations for portions of the area, perhaps targeting the Eastern Dakotas and Western Minnesota Monday.

If you have any questions do not hesitate to reach out and have a great day!