Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 310 PM EST Fri Dec 06 2019 Valid 00Z Sat Dec 07 2019 - 00Z Mon Dec 09 2019 ...Heavy Rain and Significant Mountain Snowfall to impact California and the Pacific Northwest... ...Mountain Snow and Valley Rain Extends into the Rockies on Sunday... ...Abnormally Mild Temperatures in the Heartland, Cold Finish to the Weekend in the Northern Plains... A fetch of Pacific moisture is taking aim at northern California as a potent storm system approaches from the west. Heavy rainfall is expected across the lower elevations of California, Oregon, and Washington tonight and into Saturday. Rainfall totals will range between 5-7" along portions of northern California's Coastal Ranges where flash flooding is a concern. Burn scarred areas are most at risk for flash flooding, thus portions of coastal northern California are under a Slight Risk for excessive rainfall. Parts of the Sacramento Valley are also under Flash Flood Watches through Saturday evening. Winter Storm Warnings are in effect across the Sierra Nevada where snow will be the primary precipiation type with copious amounts of snowfall expected. Snow will be measured in feet this weekend along the higher terrain of the Sierra Nevada with significant travel impacts expected. The West Coast storm system will send its stream of Pacific moisture inland late Saturday and into Sunday. This will lead to mountain snowfall and valley rain across the Intermountain West. Snow totals may approach a foot or more in parts of central Idaho and western Wyoming. A milder temperature regime will take shape in the Nation's Heartland this weekend. Temperature anomalies of 10 to 20 degrees above normal will be common from the Midwest to Texas. After a mild start to the weekend, the Northern Plains will watch temperatures plummet Sunday as a surge of frigid air blasts into the region. Sunday high temperature anomalies will range between 10 to 20 degrees below normal in the Dakotas. Mullinax Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php