Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 PM EDT Tue Oct 20 2020 Valid 00Z Wed Oct 21 2020 - 00Z Fri Oct 23 2020 ...Active weather pattern through the middle of the week... ...Elevated Fire Risk continues for northern California... A deepening upper-level low will generate a range of weather types across the continental U.S. through Thursday. An area of low pressure is forecast to develop in the Midwest tonight along a frontal boundary draped from the Southern Plains into the Northeast. This low is forecast to strengthen and help enhance rain and scattered to isolated thunderstorms along its boundary tonight. It's also forecast to produce snow mixed precip across the Upper Midwest. Rain and thunderstorms should continue across the Lower Great Lakes and interior New England through Wednesday night. The upper-level pattern will amplify over the Northern Rockies on Thursday and strengthen a low pressure system over the Central Plains. This dynamic system will produce heavy snow to the northwestern Montana part of the Rockies, and rain/snow across the Northern Rockies/Plains tonight through Wednesday evening before the amplification occurs and plunges a very cold airmass into the region. which will turn the mixed precipitation to all snow on Thursday. The low will cross into the Upper Midwest on Thursday while continuing to generate heavy snow from the Northern Rockies into the Northern Plains. Rain and scattered thunderstorms are expected to continue along the northern part of the Midwest boundary through Thursday evening. The Critical Threat of Fire Weather continues across northern California through Friday due to the persistence of warm/dry conditions over the region. Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php