Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 258 PM EST Sat Dec 07 2019 Valid 00Z Sun Dec 08 2019 - 00Z Tue Dec 10 2019 ...Strong storms with heavy rain and higher elevation snow expected for central and northern California through tonight... ...Locally heavy snow for the central and northern Rockies beginning tonight with accumulating snow spreading east into the north-central U.S. late Sunday... ...Significantly colder temperatures coming to the central and northern U.S. starting Sunday... A potent storm system will enter northern California tonight bringing locally heavy rain and mountain snow to central and northern portions of the state. Flash flooding will be possible for portions of northern California with sensitive burn scar regions at greatest risk for enhanced runoff and debris flows. At elevations above roughly 6000 ft, heavy snow is expected with storm total accumulations of 1-3 feet in the Sierra Nevada. As the storm system moves into the Interior West, a mix of rain and snow (depending on elevation) will spread across most locations west of the Continental Divide. The threat for heavy rain will diminish across inland locations of the West but through Sunday, locally heavy snow will be possible for the higher elevations of the Rocky Mountains across western Montana into northwestern Wyoming and portions of central Colorado. Low pressure is forecast to develop in the northern High Plains on Sunday and track eastward into Iowa by Monday morning. Light to moderate snow is expected north of the low track with snowfall accumulations 3 to 6 inches, with embedded higher totals, likely to fall from eastern Montana into central Minnesota and into the U.P. of Michigan. The trailing cold front will be followed by a surge of modified arctic air into the northern and central U.S. For Sunday and Monday. Forecast high temperature departures from average will drop from +10 to +20 today (Saturday) to -10 to -20 degrees below average on Monday from the Central Plains into the Red River Valley of the north. Across the East, fair weather will continue into Sunday beneath the influence of a departing surface ridge. Temperatures will warm well above average for Sunday for many folks from the Mississippi Valley to the East Coast, but clouds and rain showers will be on the increase through Sunday evening. Otto Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php