Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 326 PM EDT Mon May 20 2019 Valid 00Z Tue May 21 2019 - 00Z Thu May 23 2019 ...A significant severe weather and flash flood event is likely today across parts of Texas, Oklahoma and Kansas. ... ...Heavy snow expected for the central Rockies with well below average temperatures extending from the central and northern High Plains into much of the West through Wednesday... ...Critical fire weather environment will be in place in far Western Texas into Southern New Mexico today through Wednesday ...Above average warmth for the East Coast today with much cooler temperatures for the Northeast on Tuesday into Wednesday... A major spring storm system is already starting to affect portions of the Southern Great Plains with the potential for widespread severe weather including potential violent long track tornadoes, large hail and significant high winds across northwestern Texas into Oklahoma where the Storm Prediction Center (SPC) is forecasted a High Risk of severe thunderstorms. A Moderate and Enhanced Risk expands further south into the Permian Basin and Lower Pecos River Valley and east to the Arkansas border. A Slight Risk surrounds the area into much of Kansas and surrounding the Enhanced Risk areas. Along with the severe weather, a very high moisture environment exists as well across the area resulting in these storms producing the potential for flooding, likely flashy with the strongest downpours, long duration of rainfall as well as repeat cells; as a result the Weather Prediction Center (WPC) has issued a High Risk for central to northeast Oklahoma. A Moderate Risk extends back into northwest Texas, as well as, southeastern Kansas, southwest Missouri and Northwest Arkansas. Rainfall totals across these areas are expected to be on average around 3 to 6 inches but are likely to be locally higher in locations of longest duration/repeat thunderstorms. The threat of severe will shift eastward for Tuesday across the Ozarks of Missouri and northern Arkansas, and will not as widespread as today, it is potentially dangerous as the SPC has issued an Enhanced Risk of severe weather; a Slight Risk extends south into Northeast Texas as well as further west near the surface low across central and eastern Kansas. Severe weather into Wednesday will further reduce in coverage and intensity as the strong surface cyclone begins to weaken. Once again heavy rainfall will be expected but not to the coverage and intensity, going through Tuesday into Wed. WPC has issued a Slight Risk downstream of today's activity with much of Missouri, eastern Kansas, northeast Oklahoma, northern Arkansas, and southern Illinois under the risk for flash flooding, with similar areas at reduced coverage (Marginal Risk) highlighted for Wednesday. On the northern and western portion of the deep surface low, temperatures (particularly day time highs) are going to be well below average with temperatures 20 to 30 degrees below normal across Arizona/Four Corners, Central High Plains of eastern Wyoming, western Nebraska, northeast CO and portions of adjacent South Dakota and Kansas. The remainder of the Intermountain west will be 10 to 20 degrees below normal as well. These ares will remain cold through Wednesday with similar ranges but shifting slowly northeast into Montana/Wyoming as above average temperatures being to shift back across the eastern fringes of Nebraska/Kansas. Temps will remain very cold across Arizona into Southern California through Wednesday as well. As a result, the moisture wrapped around the deep cyclone into the Rockies by Tuesday setting the stage for heavy mountain snow for portions of Wyoming, Colorado, Utah, and Montana where 1-2 feet could fall in elevations above 9000ft through Wednesday. Minor but impactful snow accumulations are also possible for the foothills, higher plains of eastern Wyoming into far western Nebraska. Behind the cold front and dry line, very low relative humidity and high winds result in dangerous fire weather conditions mainly across southern New Mexico into far portions of West Texas (west of the Davis Range). The SPC has issued a Critical Fire Weather area for these area today through Wednesday. Out East, high temperatures will be well into the 80s and low 90s from Florida and Georgia to New England today. These temperatures are 10-20 degrees above mid-May averages across the Mid-Atlantic to New England. A cold front will change that for Tuesday however, with high falling back into the 50s and 60s for the Northeast with 70s into the northern Mid-Atlantic region about average (south) to 10-15 degrees below average in northern New England. By Wednesday, however, warm temperatures will surge northward again across the Central Mississippi River and Ohio River Valleys into the Carolinas with anomalies of 5-10 above normal are expected. Gallina Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php