Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 128 AM EST Sat Nov 18 2017 Valid 12Z Sat Nov 18 2017 - 12Z Mon Nov 20 2017 ...Heavy precipitation possible over parts of the Northwest, Ohio Valley, Lower Great Lakes, and Northeast... The first system to impact the lower 48 this period is a complex low pressure currently in the central Plains. The cyclone is expected to strengthen as it moves east-northeast across the Upper Midwest, Great Lakes, and Northeast, spreading heavy precipitation as it and its associated warm front approach. In its wake, Lake Effect snows are expected downwind of the Great Lakes within the main zone of its associated cold advection. A strong surface high across the Great Basin is expected to lead to a weak Santa Ana across portions of the L.A. Basin today, which should continue warmth across the area and lead to elevated fire weather risk per guidance from the Storm Prediction Center. Across the Pacific Northwest, onshore flow ramps up as a cold front approaches the region which should lead to heavy rains and higher elevation snows as the front moves into the area. Roth Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php