Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 328 AM EDT Fri May 28 2021 Valid 12Z Fri May 28 2021 - 12Z Sun May 30 2021 ...Severe thunderstorms and isolated flash flooding possible across the Southern Plains and Mid-Atlantic through Saturday... ...Below average temperatures found throughout much of the central and eastern United States this Memorial Day weekend... A low pressure system entering the Ohio Valley this morning is forecast to bring widespread showers and locally heavy rain to the central Appalachians and Mid-Atlantic today. Additionally, thunderstorms are likely to form along and south of an associated warm front that is expected to slowly lift northward across the Mid-Atlantic today. A few storms may turn severe, particularly throughout central and northern Virginia, with damaging wind gusts, large hail, and isolated tornadoes possible. The system is then expected to stall as it reaches the East Coast on Saturday, leaving a stiff northeast wind and light rain to linger through the weekend for the Mid-Atlantic region and Northeast. Meanwhile, showers and thunderstorms will also continue to form along an attached cold front that currently extends from the middle Mississippi Valley to the Southern Plains. This cold front is forecast to push southward and reach the Gulf Coast by Saturday morning, while remaining draped across the Southern Plains. Heavy rain and severe thunderstorms will be a concern both today and Saturday throughout the southern High Plains, as well as portions of central Texas. Multiple rounds of thunderstorms could lead to several inches of rain today in the aforementioned region. WPC has issued a Slight Risk of Excessive Rainfall that includes parts of central and West Texas to highlight the flash flooding threat. Severe weather may also accompany thunderstorms in the southern High Plains today and Saturday. Large hail and isolated tornadoes will be possible from southeast New Mexico to West Texas before the threat shifts slightly north for the beginning of the weekend. Speaking of the weekend, many with outdoor plans in the central and eastern U.S. will have chilly temperatures to contend with. In fact, portions of the northern Plains and northern New England are waking up to patchy frost and temperatures near freezing this morning while a strong high pressure system settles over the region. Farther south, highs will struggle to escape the 40s in the Midwest today. Overcast skies, showers, and a northeast breeze will also make for a cold Memorial Day weekend along the Northeast and Mid-Atlantic. High temperatures in the 50s on Saturday equates to around 20 degrees below average and could lead to several daily record low maximum temperatures. Heat won't be hard to come by throughout the West however, as triple digit temperatures are forecast across the Desert Southwest and Sacramento/San Joaquin valleys of California. Snell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php