Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 240 PM EST Sat Nov 19 2016 Valid 00Z Sun Nov 20 2016 - 00Z Tue Nov 22 2016 ...Strong storm system lifting northward over southern Canada... ...Colder temperatures arriving to the eastern states... ...More showers and mountain snow for the western states... The robust low pressure system that brought widespread snow from the Central Rockies to the Upper Midwest/Great Lakes region on Friday is lifting north and east through southern Canada. The cold front extended from the central low pressure is pushing through the eastern states this afternoon. A significant drop in temperatures is expected with the passage of the front by tonight/early Sunday, lingering into the coming week. Widespread highs in the 30s and 40s are forecast. Cold northwesterly winds across the Great Lakes will lead to the first noteworthy lake effect snow event this fall from the Upper Peninsula of Michigan to upstate New York, where numerous winter-related advisories and warnings are in effect. Accumulating snow is also expected for the central and northern Appalachians beginning tonight. Another Pacific storm system is expected to bring showers and mountain snow for this weekend across the West. The heaviest precipitation should be from the Sierra Nevada to the Pacific Northwest coast, and lighter rain/snow across the Intermountain West. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php