Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 407 PM EDT Fri Apr 27 2018 Valid 00Z Sat Apr 28 2018 - 00Z Mon Apr 30 2018 ...Rain and cooler conditions expected with a new storm system coming into the western U.S. this weekend... ...Moderate to heavy rains will continue to lift out of the Northeast Friday evening... ...Record lows possible across the Midwest and Lower Ohio Valley Sunday morning... A gradual cooling trend is expected across the western U.S. this weekend as an expansive upper low edges inland from the Pacific. This system will also bring light to moderate rain and mountain snow to the favored terrain of the Pacific Northwest, northern California, and the northern Rockies, while moisture returning ahead of the system will increase the chance for showers and thunderstorms across the southern Rockies and adjacent High Plains. Downstream, daytime temperatures should reach as much as 10 to 20 degrees above normal across portions of the central to northern Plains Saturday and Sunday as an upper ridge shifts eastward from the Rockies to Great Plains. Moderate to heavy rain will continue to lift out of the Northeast Friday evening as a weak wave of low pressure quickly tracks towards Canada. Behind this system, a surge of cooler air and scattered precipitation will accompany a cold front pressing eastward out of the Great Lakes on Saturday. The surge of cooler air could result in some record low temperatures and snow showers across portions of the Ohio Valley and Great Lakes region Sunday morning. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php