Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 331 PM EDT Tue May 17 2016 Valid 00Z Wed May 18 2016 - 00Z Fri May 20 2016 ...Severe thunderstorms possible for parts of Texas... ...Heavy rain possible over portions of Texas... ...Temperatures will be 10 to 20 degrees below average from the Central Appalachians westward to the Central/Southern Rockies and Southern Plains... A deep upper trough over the Southwest will be slow to push out into the Southern Plains setting the stage for a wet period across Texas. Moisture from the Gulf will work its way up along the eastern slopes of the Sierra Madres in southeasterly flow across Southern Texas and Northern Mexico. Widespread showers and thunderstorms will affect the Southwest and Southern Plains under the influence of the upper trough and associated upper level jet. The Big Bend area of Texas into Southern Texas will be in a favorable environment for more organized thunderstorms with some severe thunderstorms possible today. The severe weather threat area will shift slightly westward for tomorrow as the upper level dynamics consolidate over Western Texas. With numerous rounds of showers and thunderstorms expected in a very moist environment, heavy rainfall is expected across a broad area of Texas through the period. Elsewhere, a frontal boundary will push across the Eastern U.S today and tomorrow with precipitation mainly focusing across Florida and the Southeast coastline. Temperatures across much of the central and eastern U.S. will continue to be below normal. A broad region from the Rockies to the Mid Atlantic will be up to 20 degrees below normal today. In the Pacific Northwest a cold front will come ashore by tomorrow morning but the lack of moisture will limit the precipitation. The front will strengthen while crossing the Intermountain West as the associated upper level low rapidly deepens over the region. Above normal temperatures will give way to below normal readings behind the front. Portions of the Northern Plains will see above normal temperatures with deep south to southwesterly flow ahead of the front. Krekeler Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php