Today will feature generally quiet weather across the country as the last system we discussed has now moved well off the East Coast. The most active weather will be found across Montana and adjacent parts of the High Plains as our next system to watch begins to drift East off the Rockies.
Here’s the ECMWF’s overview map for today highlighting the generally quiet weather outside of that area of snow. So what’s causing this snow, what impacts will it bring, and how much should you expect?
This synoptic composite map from the ECMWF (what’s that?) highlights some of the dynamics that will be at play in this area this afternoon. At the surface, Arctic high pressure will be surging south, bringing very cold air with it. In the mid levels, Pacific air/moisture will be overrunning this low level cold airmass, a process that generates upward motion and precipitation. This upward motion will only be accentuated by a jet streak aloft, whose left exit region (a favorable area for upward motion) will be located over Montana. The combination of the cold air, the moisture, and the upward motion means that we’re all set to track snow in this area this afternoon.
This simulated radar image (from weathermodels.com) shows the net result of the dynamics discussed above. Notice the large area of light-moderate snow across Central Montana, with embedded very heavy bands. While total snowfall amounts may not be all that impressive, especially by Montana standards, it won’t take much accumulation in a short time in one of those heavier bands to cause some problems out on the roads. Use caution if travelling in this area today, and be aware for the potential of rapidly changing visibility and road conditions.
Here’s the National Weather Service snowfall forecast through late tonight showing a widespread area of >6″ of snow in the Central/Eastern part of Montana. Farther west, totals will be more elevation dependent with lower elevations remaining snowless and higher elevations seeing over a foot. Map from weathermodels.com.
Elsewhere across the country, generally quiet weather is expected.
For more information on your local forecast: https://weather.us/
For more information on the local forecast for ME/NH: https://forecasterjack.com/2018/02/08/cooling-temps-and-clearing-skies-today/