Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 325 AM EDT Tue Aug 20 2024 Valid 12Z Tue Aug 20 2024 - 12Z Thu Aug 22 2024 ...Severe thunderstorms possible across the central to northern High Plains through Wednesday with flash flood potential continuing over the Southwest... ...Record breaking heat continues across Texas... After several days of active and unsettled weather, the cold front across the eastern U.S. has finally largely cleared the coast, aside from coastal Maine where a few lingering showers will remain possible through this morning. Otherwise, sprawling high pressure will encompass much of the Great Lakes region through the East, bringing much drier conditions and generally below normal temperatures for the next couple of days. High temperature departures of 10 to nearly 20 degrees for mid-August are expected for Great Lakes and Northeast. Plan on highs only in the 60s and 70s for many areas from the Midwest to northern Mid-Atlantic and Northeast. This high pressure is expected to dominate the weather story for the region through at least mid-week, from the Mississippi River to the Appalachians. A nearly stationary front will settle to its south across the Gulf Coast region and then extending northward across the High Plains, along the western periphery of the high pressure axis. This boundary, along with interactions with another passing weather system passing through the Northern Rockies, will bring threats for severe thunderstorms to much of the central and northern High Plains through Wednesday. The Storm Prediction Center is advertising a Slight Risk (Level 2 of 5) for severe weather including damaging winds and large hail. Meanwhile, deep monsoonal moisture persistent over the Southwest U.S. will bring a daily threat of localized and isolated flash flooding. Slow moving but intense rainfall producing thunderstorms are possible across portions of Arizona, Utah, Colorado, and New Mexico. For today, the threat appears to be fairly localized, a greater threat will exist for Wednesday across northern Arizona where a Slight Risk (Level 2 of 4) of excessive rainfall and flash flooding exists. Finally, underneath a strong upper level ridge, record breaking heat will continue for at least a couple more days across portions of Texas and southern Oklahoma. Excessive Heat Warnings and Heat Advisories remain in effect and many daily record high temperatures will be possible as temperatures soar into the 90s and triple digits. Combined with the oppressive humidity, daily maximum heat indices up to 110F will be possible. This will create a dangerous situation for some groups, particularly anyone spending large amounts of time outdoors. They will be at a heightened risk of heat-related illness. Some of the heat is expected to spread into eastern New Mexico by the middle/end of the week. Taylor Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php