Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 355 AM EDT Tue Oct 15 2013 Valid 12Z Tue Oct 15 2013 - 12Z Thu Oct 17 2013 ...Heavy rain possible over parts of the Southern Plains/Lower Mississippi Valley... ...Temperatures will be 10 to 20 degrees below average from the Northern/Central High Plains to the Great Basin and the Northern/Central Rockies... A storm over the Upper Midwest will move northeastward into western Quebec by Wednesday evening. Moisture flowing northward out of the Western Gulf of Mexico will pool along the associated front aiding in the development of showers and thunderstorms over the Southern Plains/Lower Mississippi Valley. The showers and thunderstorm will advance eastward along with the boundary into parts of the Lower Great Lakes to the Lower Mississippi Valley by Wednesday evening. In addition, moderate to heavy rain will develop over parts of the Upper Midwest on Tuesday morning. The area of rain will have a few embedded thunderstorms over the Great Lakes by Tuesday evening. On the backside of the system, light snow will develop over parts of the Northern Plains that will end by Tuesday afternoon. Meanwhile, upper-level energy over the Four Corners Region will move eastward to the Southern/Central Plains by Wednesday. The energy will produce light snow over parts of the Central Rockies starting Tuesday evening and expanding slightly into the Southern Rockies on Wednesday morning, with rain at lower elevations before ending later on Wednesday. A second front will move southeastward, on Wednesday morning, from West-Central Canada into parts of the Northern Plains/Northern Rockies by Wednesday evening. The system will produce light rain over parts of the Northern Rockies/Northern High Plains on Wednesday. Elsewhere, easterly flow off the Atlantic will produce scattered light rain along parts of the Southeast Coast through Wednesday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php