Today will feature the continued eastward expansion of snowfall associated with a storm system that moved ashore in the Pacific Northwest a couple days ago. Because there’s now an entire mountain range between this system and its moisture supply, snow will be lighter today than in previous days. Out ahead of this system, a very cold high pressure system will establish control of the Northeast with cool and quiet weather expected today. Tomorrow, this high pressure center will be important as battle lines are drawn between cold air in place and warm air being drawn north by the incoming storm. I’ll have much more on this setup tomorrow including what’s behind it, and what it means for your forecast!
Here’s the ECMWF’s overview map for today. Notice the area of light snow extending from the Great Lakes back into the Plains. This is where a couple inches of accumulation are possible during the day today, along with reduced visibilities and slick roads. As you head towards Omaha and Kansas City, temperatures are likely to be too warm for snow, so a rain/snow mix is likely in those areas. Outside of that storm system, however, very quiet weather is expected on both coasts.
How much snow is expected? Here’s a look at the ECMWF”s liquid equivalent precipitation forecast (what’s that?) through tonight. A general 1-2″ of snow is expected from just north of Denver over towards Sioux Falls and Green Bay. The lack of moisture will preclude higher totals outside of the Rockies SW of Denver, where higher totals are expected due to the closer proximity to the Pacific moisture source. All in all, this system won’t be much more than a nuisance today, just take it slow if you’re travelling through areas expecting snow covered roads.
Both the West Coast and the East Coast will see quiet weather today as high pressure builds in on both sides of this system.
For more information about your local forecast: https://weather.us/
For more information about the local forecast for ME/NH: https://forecasterjack.com/2017/12/21/cool-and-calm-today-5/