Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 227 PM EST Mon Feb 20 2017 Valid 00Z Tue Feb 21 2017 - 00Z Thu Feb 23 2017 ...Heavy rain and mountain snow possible into Tuesday across portions of the western U.S... ...Heavy rain possible into Tuesday across portions of the central Gulf Coast... ...Record high temperatures possible through midweek across portions of the central and eastern U.S... A plume of Pacific moisture and a vigorous low pressure system will continue to bring widespread rain and mountain snow to portions of California, the Pacific Northwest, and the northern Great Basin tonight and into much of Tuesday. Heavy rain may result in flooding for some areas, and heavy snow will be possible at high elevation locations. The low pressure system is expected to move reach the Pacific Northwest coastline early Tuesday morning, and then move inland during the day. Precipitation should begin to decrease in coverage and intensity for some areas along the West Coast later Tuesday as the system moves inland. The system will also bring potentially heavy snow to portions of the northern Rockies tonight through Tuesday. On Wednesday, as the area of low pressure moves east, snow will be possible for portions of Nevada and Utah as well. Farther east, a slow-moving upper-level low and surface frontal system will bring showers and thunderstorms from the central Gulf Coast to the Great Lakes tonight and Tuesday morning. Storms could produce heavy rainfall across the central Gulf Coast. The northern end of the system will spread a mix of scattered light rain, freezing rain, and snow into portions of the Northeast late Tuesday as well. The other major weather story through midweek will be the record warmth across large areas of the central and eastern U.S. A broad area of high pressure at the mid and upper levels of the atmosphere will support well above average temperatures for many areas. High temperatures on Tuesday are forecast to be 20 to 40 degrees above average from the central and northern plains to the Great Lakes, with many areas reaching well into the 70s. On Wednesday these temperatures will expand eastward with high temperatures exceeding 20 degrees above average over portions of the Mid-Atlantic region. Record high temperatures are possible across these areas through Wednesday. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php