Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 301 AM EST Mon Jan 02 2017 Valid 12Z Mon Jan 02 2017 - 12Z Wed Jan 04 2017 ...There is a slight risk of severe thunderstorms over the Central Gulf Coast... ...Heavy rain possible over the Central/Eastern Gulf Coast... ...Heavy snow possible for Northern California and the Sierras... ...Heavy snow from parts of the Northern Plains to the Upper Great Lakes... A storm over Texas will move northeastward to the Mid-Atlantic Coast by Tuesday evening. The system will produce showers and thunderstorms from parts of the Southern Plains to the Southeast that will move off the Southeast Coast by Tuesday evening. The showers and thunderstorms will move into parts of the Ohio Valley by Monday evening ending overnight Monday and likewise over the Southern Plains and Lower Mississippi Valley. Meanwhile, upper-level energy over the Northern Rockies/High Plains will move eastward to the Upper Great Lakes by Tuesday evening. The storm will produce snow over parts of the Northern/Central Rockies to the Upper Great Lakes by Monday morning. Snow A lingering frontal boundary extending from the southern plains to the Southeast will continue to focus areas of showers and thunderstorms through tonight. Some thunderstorms could be severe through tonight across portions of the southern plains, and heavy rain is possible for portions of the Gulf Coast and Southeast. Monday morning, an area of low pressure will develop along the frontal boundary across northeastern Texas as an upper-level disturbance approaches. The low pressure system will move northeastward across the lower Mississippi valley on Monday. Numerous showers and thunderstorms are expected from the Ohio valley to the Gulf Coast and Southeast on Monday. Heavy rainfall is once again possible, in addition to severe thunderstorms for some areas. Please refer to products issued by the Storm Prediction Center for further details on the severe weather threat. Also on Monday, a second area of low pressure is forecast to develop along the southern Mid-Atlantic coastline, and move northeastward along the coast. This low will spread rain north across the Mid-Atlantic and into the Northeast by late Monday into Tuesday. Cold air in place will allow precipitation to fall as a mix of snow, sleet, and freezing rain across some areas from Upstate New York to northern New England. Farther west, cold air is expected to remain in place as an upper-level trough remains overhead. Additionally, an arctic surface front will drift south through Monday, ushering another round of frigid air associated with an arctic surface high into areas from the Pacific Northwest to the northern plains. The continued presence of upper-level energy will keep areas of snow in the forecast from portions of the Pacific Northwest and northern California to the Rockies on Monday, with heavy snow possible for some areas. A cold air mass already in place will allow precipitation to fall as snow, or a mix of snow and rain even at the lower elevations along the coast of Oregon and northern California. Precipitation will begin to increase across the West Coast once again on Tuesday as another Pacific low pressure system approaches. Additional upper-level energy will eject eastward across the northern plains, spreading a mix of precipitation types east into the northern and central plains on Monday. Snow, heavy for some areas, is expected from the northern High Plains to much of the Upper Midwest, with a band of freezing rain possible in the transition zone between snow and rain, from the northern/central plains to the Midwest. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php