Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 315 AM EST Fri Dec 02 2016 Valid 12Z Fri Dec 02 2016 - 12Z Sun Dec 04 2016 ...Heavy rain possible over Eastern Texas and parts of the Lower Mississippi Valley... ...Heavy rain possible over the Olympic Peninsula... ...Heavy snow possible over the Cascades... A developing upper-level low over Northwestern Mexico will pull moisture off the Western Gulf of Mexico over parts of the Southern Plains into the Lower Mississippi Valley through Sunday. Showers and thunderstorms will develop over parts of the Western Gulf Coast and expand into the Texas Panhandle by Friday evening continuing into Saturday evening. Snow will develop over parts of the Central/Southern Rockies on Friday afternoon ending over the Central Rockies overnight Friday. The snow will wind down over the Southern Rockies by Saturday evening. Rain will develop over parts of the Southern High Plains by Friday evening continuing into Saturday evening. Another area of rain will develop over parts of the Lower Mississippi Valley overnight Friday and expand into parts of the Tennessee Valley by Saturday afternoon into evening. The rain may be heavy at times. Meanwhile, onshore flow off the Pacific will develop over parts of the Pacific Northwest through Sunday. The onshore flow will aid in developing rain and higher elevation snow over the Northwest through Saturday evening. As the moisture moves inland, snow will develop over parts of the Northern Rockies Friday evening into Saturday evening. Snow will also develop over parts of the Northern High Plains on Saturday afternoon into evening. Elsewhere, an upper-level low over Southeastern Canada will slowly move to Newfoundland by Saturday evening. Upper-level energy circulating around the upper-level low will aid in producing lake effect snow down wind from the Great Lakes Friday into Saturday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php