Today’s weather will feature a continuation of an all to familiar pattern. The vast majority of the nation will see quiet weather while an Atmospheric River will continue to bring rain and high mountain snow to parts of the West Coast.
Our pattern is clearly visible on the national overview map which shows almost nothing in the way of significant weather East of the Rockies. Light upslope and lake effect rain and snow showers will continue in parts of the Northeast, but otherwise, the only weather of note can be found near the Pacific Ocean, where tropical moisture is streaming north, running into the coastal mountains of Northern California, Oregon, and Washington.
GOES-16 Water Vapor imagery (what’s that and how do I use it?) shows a river of tropical moisture surging north along the West Coast. This moisture will result in heavy rain and some high mountain snow today. Due to the tropical nature of the airmass, snow levels will be pushed high above the passes, and only summits above 10,000 feet will see any meaningful flakes.
Swiss Super HD model forecasts for the snow line (how high up you’d have to go to see flakes) shows this result of the tropical airmass well. While precipitation will be heavy at times today, most of it, even in the passes, will fall as rain. Rain will be occasionally heavy, so watch for flash flooding issues in the burn scars left from October’s wildfires. It won’t take much to cause some problems there.
Farther north, colder air will be in place across the Cascade and Olympic mountains, where snow will fall and accumulate today. Rain will fall in the valleys, and with snow levels remaining fairly high, no significant issues are expected. A general half inch to inch of rain is expected in the valleys, with higher totals at elevation.
For more information about your local forecast: https://weather.us/
For more information about the local forecast for ME/NH: https://forecasterjack.com/2017/11/26/becoming-cooler-and-clearer-today/