Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 345 AM EST Sun Jan 11 2015 Valid 12Z Sun Jan 11 2015 - 12Z Tue Jan 13 2015 ...Freezing rain will be possible across the middle to lower Mississippi Valley...Ohio Valley...and northern Mid-Atlantic states... ...Another Arctic blast will spread southeastward through much of the Plains and Midwest... Unsettled weather is expected across the eastern half of the Nation as a surface low spinning in the western Gulf of Mexico lifts northeastward and an Arctic boundary plunges out of the north-central U.S.. Ahead of these features...warm and moist Gulf of Mexico air pulling northward over an Arctic airmass settled in over the East will produce widespread precipitation from the central Gulf Coast to the Ohio Valley on Sunday...which will spread east of the Appalachians Sunday night into Monday. Moderate to heavy rain...with a few rumbles of thunder...will be possible for locations along the Gulf coast as well as along the Southeast to southern Mid-Atlantic coast. The Arctic air will be slow to erode...leading to periods of freezing rain across the middle to lower Mississippi Valley...Ohio Valley...and northern Mid-Atlantic states. North of the freezing rain...temperatures should remain low enough to support an axis of accumulating snow. Elsewhere across the nation...a large surface high over Canada will plunge temperatures while it slides into the north-central U.S. on Sunday. The Arctic invasion will spread south and east across much of the Plains and Midwest early this week. Weak energy aloft will produce light to moderate rain and higher elevation snow while crossing over southern California and the Southwest on Sunday. Upstream...light to moderate rain with higher elevation snow will also be possible with energy dipping into the Pacific Northwest on Sunday and amplifying over the Four Corners region late Monday. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php