Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 416 AM EDT Thu Mar 19 2015 Valid 12Z Thu Mar 19 2015 - 12Z Sat Mar 21 2015 ***Showers and thunderstorms expected across the southern states*** ***Rain and late season snow for parts of the Mid-Atlantic and Northeast*** ***Another strong cold front reaching the northern Plains by Friday*** The general flow pattern across the country over the next few days should be mainly zonal across the southern half, and an amplifying pattern across the north. One of the interesting things during this forecast period will be a developing surface low that develops near the Mid-Atlantic coast. With just enough cold air available, a late season snowfall is becoming likely from eastern Ohio to southern New England, including many of the major cities along the I-95 corridor. Most of the accumulation should occur on grassy and forested surfaces. Rain is the expected precipitation type farther to the south across much of Virginia and West Virginia. Across the southern tier of the country, an upper level low across northwest Mexico, along with its atmospheric instability across the southwest states, will help to generate afternoon and evening thunderstorms late Thursday. This system advects Pacific moisture aloft across Mexico and over the southern Plains, with a return flow off the Gulf of Mexico closer to the surface. This pattern leads to a broadening area of showers and storms stretching from the Desert Southwest to the Gulf Coast states. Across the northern U.S., a reinforcing surge of cold air arrives on Friday for the northern Plains and Upper Midwest behind a strong cold front. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php