Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 342 AM EDT Sun Jul 26 2020 Valid 12Z Sun Jul 26 2020 - 12Z Tue Jul 28 2020 ...Tropical Storm Hanna to further weaken as it moves into Northeast Mexico; torrential rainfall and severe storms expected for South Texas... ...Heavy Rainfall/flash flooding possible for parts of the Rockies and Plains over the next few days... ...Cooling trend in the Plains, becoming hotter in the Northwest, staying hot in the Northeast... Tropical Storm Hanna will move into northeast Mexico from South Texas Sunday morning. Windy conditions will slacken as the storm moves farther inland. Heavy rain -- with intense rainfall rates of 2-3" an hour at times -- will occur near and in the wake of the storm into early Monday. Copious amounts of rainfall, with overall totals up to 18", along with saturating soils will result in both flash flooding and river flooding that could become life threatening from the southern Texas coast to the Lower Rio Grande Valley. The concern for dangerous flooding in South Texas due to Hanna has maintained a High Risk for excessive rainfall through Sunday night. The heavy rain and flash flood threat extends as far north as southeast Texas and southern Louisiana as rain bands associated with Hanna continuing moving in from the Gulf. A slight risk of severe thunderstorms also exists within Hanna's outer bands across Deep South Texas Sunday. For more information on Hanna's status and expected track, see advisories from the National Hurricane Center. Elsewhere, areas of locally heavy rainfall are likely this weekend into Monday across portions of the Four Corners region, with sections of the Plains/Midwest at risk through Tuesday. Monsoonal moisture has set the stage for bouts of heavy rainfall over the Southern Rockies (Slight Risk of excessive rainfall) before the risk of heavy/excessive rainfall shifts east into the Plains. Rainfall rates may be heavy at times, particularly in the afternoon and evening hours. To the north, a Canadian low pressure system forces a cold front into the Plains which combined with the aforementioned monsoonal moisture should generate organized and potentially severe thunderstorms into the start of the week. A Moderate Risk for flash flooding is forecast from the central High Plains to Corn Belt Sunday into Sunday night, portions of the Southern and Central Plains Monday (Slight risk), and in and near Oklahoma on Tuesday (Slight Risk). The cold front sweeping across the central U.S. ushers in cooler and more comfortable conditions across the northern Rockies and Great Plains Sunday. By Monday, the surge of cooler temperatures reaches the central Plains and south-central Rockies. After a cool start to the weekend, temperatures rebound to above normal levels across the Northwest Sunday and Monday with high temps making a run at the century mark in spots. To the East, hot and humid conditions extend across much of the eastern third of the Lower 48 with heat indices in the Northeast reaching at or above 100 degrees during the afternoon into Tuesday. Record highs are possible across portions of the Mid-Atlantic States and Southern New England as temperatures soar well into the 90s Sunday through Tuesday. Roth/Mullinax Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php