Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 258 AM EST Mon Feb 18 2019 Valid 12Z Mon Feb 18 2019 - 12Z Wed Feb 20 2019 ...Unsettled weather pattern developing across the south-central part of the nation early this week... An active weather pattern is forecast to become established from Texas to the East Coast through Wednesday morning. A brief dry spell is expected through Tuesday for much of the East Coast behind the departing front Monday morning. However, the next storm system develops over the western Gulf of Mexico by Tuesday and lifts northward along a frontal zone by early Wednesday. There will be a deep northward surge of moisture from the Gulf, and the frontal boundary will lift this moisture and generate a corridor of copious rainfall from northern Louisiana to Kentucky, with widespread 2 to 4 inch rainfall amounts expected. With much of this falling on already moist ground from the rainfall this past weekend, flooding will be a concern and a moderate risk of excessive rainfall exists over parts of that region. Some strong thunderstorms may also develop across parts of the Deep South. Heavy snow is expected across the southern Rockies through Tuesday morning with a pronounced upper level trough in place along with copious upslope flow and moisture advection into the region. Winter storm warnings are in effect for southern Colorado and much of northern New Mexico with the potential for snowfall amounts in excess of a foot likely for the higher mountain ranges. The snow will begin tapering off for the Mogollon Rim of Arizona. Elsewhere across the continental U.S., frigid temperatures are expected from Montana to the Dakotas with highs in the single digits and teens with a large arctic surface high governing the weather pattern. Wind chill advisories are in effect for some areas. Snow and freezing rain are likely for the central Appalachians and the northern Mid-Atlantic by late Tuesday night and into Wednesday. Snow is also likely for the Cascades on Tuesday as a weak weather disturbance passes through the region. D. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php