Today will feature generally quiet weather from sea to shining sea as the stream of Pacific moisture and energy that has been fueling active weather over the past few days prepares to reload. While it won’t be nearly as strong or coherent as some recent days, that stream will still be flowing today, and as a result periods of rain and high elevation snow are expected in Western parts of WA and OR, as well as lighter rain and mountain snow farther east in Idaho and adjacent parts of Montana and Wyoming.
Here’s the national overview map from the ECMWF model showing those areas of precipitation this afternoon. Elsewhere across the country, scattered light showers will be about the most impactful weather you’ll find. If you look at satellite imagery though, this may seem a bit surprising.
Water Vapor satellite imagery (what’s that?) shows a trough of low pressure ejecting out onto the Plains this morning, with both Pacific and Gulf of Mexico moisture available. This is a setup that usually favors storm development, such as the system earlier this week that brought blizzard conditions to parts of the Plains. However, the most impactful weather in the forecast today for the Plains is a few light showers. What’s making this setup so unfavorable for storm development?
Here’s the ECMWF’s 500mb height/energy forecast for this afternoon that explains why. Notice that we do indeed have our trough, ahead of which rising motion is favored. However, the energy associated with the trough is disorganized and all over the place. There are three disturbances that would need to come together to form a storm, yet today they’ll be scattered hundreds of miles away from each other. With no interaction between the three disturbances, and the upstream ridge replaced by a zonal Pacific jet, there won’t be any storm today even as all that moisture and energy emerges onto the Plains.
Map from weathermodels.com.
The ridge of high pressure visible in the map above will ensure continued quiet weather for the East today.
For more information on your local forecast: https://weather.us/
For more information on the local forecast for ME/NH: https://forecasterjack.com/2018/01/26/slightly-warmer-today-6/