Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 139 AM EST Mon Jan 11 2021 Valid 12Z Mon Jan 11 2021 - 12Z Wed Jan 13 2021 ...Winter weather spreads and wanes from Lower Mississippi Valley to Central/Southern Appalachians today... ...Heavy rain/snow to impact portions of the Pacific Northwest over the next couple of days... ...Warm air expands over northern tier of the country while colder air retracts over the Deep South... The low pressure system currently gliding across the Gulf coast will move across Florida and into the Atlantic late tomorrow. Snow is likely to wind down across the Southeast today while rain and thunderstorms impact the coast through tonight. Additional snow amounts are likely to remain below an inch in most places. Some light showers are possible along the Southeast coast tomorrow as the system moves off into the Atlantic. Winter Storm Advisories and Warnings remain in effect for parts of eastern Texas through the Lower Mississippi Valley. Highs are expected to be much below average across Texas and the Lower Mississippi Valley today as the low pressure system pulls cool air down and high pressure expands over the area. Temperatures may be down to 25 degrees below average in some places today. This cool air mass is likely to recede over the Southern Plains on Tuesday as the system moves off into the Atlantic. Meanwhile the Northern/Central Plains will see anomalously warm air infiltrate into the region through Tuesday with highs likely to be over 25 degrees above average in some places. A continuous stream of low pressure will pull enough Pacific moisture to dump substantial rain over the Pacific Northwest through the next couple of days. Slight and Moderate Risks of Flash Flooding are in effect over the coastal Pacific Northwest today and tomorrow, respectively, when multiple inches of rain are expected to fall. Heavy snow is also expected over the higher elevations of the region, particularly over the northern Cascades where over 2 feet of snow may fall. Snow will expand into the Northern Rockies late tonight and into Tuesday where 6-8 inches are possible with isolated higher amounts. Northwesterly winds are likely to produce lake effect snow for upstate New York over the next couple of days. Kebede Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php