Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 330 AM EDT Mon May 31 2021 Valid 12Z Mon May 31 2021 - 12Z Wed Jun 02 2021 ...Excessive heat found across the western United States... ...Heavy rain and flash flooding are likely today across portions of north-central Texas, while severe weather remains possible across the southern High Plains... ...Showers and thunderstorms to spread eastward into the Lower/Middle Mississippi and Ohio valleys by Tuesday... Blistering heat will be felt across the western U.S. this Memorial Day and extend into the beginning of June. Triple digit high temperatures are forecast across the Southwest and portions of central and northern California, which could break a few daily high temperature records over the next couple of days. Excessive Heat Warnings and Heat Advisories have been issued throughout central and northern sections of the Golden State. Residents are advised to drink plenty of water and avoid extended periods of time outdoors if possible. The heat is expected to expand north and into the Northwest on Tuesday. High temperatures in the 90s are forecast as far north as interior Washington. Much of the Southern Plains will once again need umbrellas handy as widespread shower and thunderstorm activity closes out the month of May. A low pressure system located over Oklahoma and a slow moving attached cold front extending across central and western Texas will be the focus for thunderstorm complexes and numerous downpours. The biggest impact from these thunderstorms will likely be associated with flash flooding. Much of north-central Texas has seen above normal rainfall over the last two weeks and an additional 1 to 3 inches of rain today could lead to an abundance of water runoff and swollen rivers/streams. WPC has issued a Moderate Risk of Excessive Rainfall that extends along the I-20 corridor in Texas, roughly from Abilene to Dallas. Severe weather is also a concern, particularly over southwest Texas and far southeast New Mexico. SPC has issued a slight risk of severe thunderstorms across this region, with damaging wind gusts, isolated tornadoes, and large hail possible. Additional rounds of thunderstorms are forecast on Tuesday as well, but should be more scattered in nature and lead to less impacts. Elsewhere, precipitation is expected to spread eastward into Arkansas and Missouri on Tuesday before reaching parts of the Midwest and Ohio Valley early on Wednesday. A few storms may turn severe across the Lower Mississippi Valley and Southern Plains, with flash flooding also a possibility on Tuesday from southern Missouri to central Texas. High temperatures will remain on the cool side throughout the central and eastern United States today, but a warming trend will commence by the first day of June. A high pressure system building in the western Atlantic will funnel tropical moisture and warmer temperatures along the East Coast. High temperatures in the 70s and 80s on Tuesday will be a far cry from the 40s and 50s experienced this past weekend. Snell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php