Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 358 PM EDT Fri May 21 2021 Valid 00Z Sat May 22 2021 - 00Z Mon May 24 2021 ...Additional heavy rain associated with a low pressure system over the western Gulf of Mexico could impact eastern Texas tonight into Saturday... ...Thunderstorms could become severe ahead of a cold front through the High Plains for the next few days... ...Late-season snow will linger across higher elevations of the West from the Sierra Nevada to the Northern Rockies into the weekend... ...Critical Risks of fire danger remain in place for portions of the Four Corners states... Winds circulating around a large high pressure system centered over the northeastern U.S. will continue to direct a stream of tropical moisture from the Gulf of Mexico toward the western Gulf states. Furthermore, a low pressure center in the Gulf of Mexico has formed in the western Gulf, which is forecast to track toward the Texas Gulf Coast tonight. The National Hurricane Center is monitoring this area for the potential for tropical cyclone formation. This combination of factors could lead to additional heavy rain particularly across southeastern Texas through tonight, and a Slight Risk of flash flooding is in place there. Portions of Texas and Louisiana have seen multiple days of heavy rain recently, so flooding could be exacerbated by additional rainfall. Some showers and thunderstorms could continue through Saturday in the Southern Plains. Meanwhile, the upper-level pattern is expected to stagnate over the next couple of days, with a deep upper-level low across the western U.S. that should eventually move northeastward a bit by Sunday, and generally large-scale upper ridging over the eastern U.S. Areas of the High Plains should have a persistent threat for scattered thunderstorms ahead of a slow-moving surface front ahead of the upper low. Some severe storms are expected, and the Storm Prediction Center has Slight Risks of severe weather delineated through the weekend for portions of the High Plains. Showers and thunderstorms are also possible for the north-central U.S. and over the Northeast through the weekend along meandering fronts. Underneath the upper low, temperatures are expected to remain below normal for much of the western U.S. through the weekend. High temperatures are forecast to be generally 15 to 25 degrees below average for the Intermountain West, and parts of Montana could stay 25 to 30 degrees below average, with record lows possible as well there. These cold temperatures will support wet snow for higher elevations of the West. The heaviest snow is ending across the Northern Rockies and Winter Storm Warnings have expired, but some additional snow is still expected in higher elevations of the Sierra Nevada into the Intermountain West and Northern Rockies through the weekend as a low pressure system is forecast to intensify over Wyoming on Sunday. Farther south, gusty winds across the interior West together with dry conditions will continue to elevate the risk of wildfires. Critical fire risk is forecast for the Four Corners states through the weekend, while Elevated Risks are in place through this evening in the Southern High Plains and portions of California. Meanwhile, warmer than average temperatures are forecast to continue for the Great Lakes/Ohio Valley and Northeast/Mid-Atlantic over the next several days under the upper ridge, with highs rising well into the 80s and even into the 90s. Tate/Kong Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php