Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 PM EDT Wed Jun 30 2021 Valid 00Z Thu Jul 01 2021 - 00Z Sat Jul 03 2021 ...Prolonged heat wave continues across interior sections of the Northwest and Northern Rockies, now extending into the Northern High Plains... ...Cold front to bring the chance of severe weather, heavy rain, and flooding to the East... ...Flood threat continues from the Ohio Valley to the Desert Southwest... The oppressive heat continues for interior sections of the Pacific Northwest and Northern Rockies. While the temperatures are not quite as high as earlier in the week, daily highs still in the upper 90s to lower 100s after the recent extreme heat will be of little relief. Excessive Heat Warnings remain in effect for eastern Washington and Oregon as well as portions of northern and western Idaho, with Heat Advisories extending into portions of northern Nevada and California. The upper-level high that has remained over the region will gradually shift to the east throughout the period, bringing the hot temperatures further into the Northern Rockies and Northern High Plains. Daily high temperatures will peak over 100 starting on Thursday, with Excessive Heat Warnings and Watches also in effect for eastern Montana and Heat Advisories in effect along and east of the Northern Rockies. In the East, a cold front will being to slowly progress to the southeast across the Northeast, Mid-Atlantic, and Southeast. While this front will bring relief from the hot and particularly muggy past few days, the moist and buoyant airmass will lead to the chance for severe thunderstorms. The Storm Prediction Center has issued an Enhanced Risk of severe weather through this evening for portions of Southern New England as well as a Slight Risk stretching from western Pennsylvania northeast to coastal Maine. The main threat from these storms will be high winds. There is a Slight Risk in effect for Thursday for eastern portions of the Mid-Atlantic as the cold front continues to progress southeastward. High winds will again be the main threat with these storms. In addition to the severe weather, widespread showers and thunderstorms are likely ahead of the front from coastal New England to the Southeast throughout the forecast period. In particular, there is a Slight Risk of excessive rainfall from the Mid-Atlantic southwest through the southern Appalachians and into the Tennessee Valley for Thursday. Storms may produce rainfall in excess of 1" per hour, leading to the risk for flash flooding. A Marginal Risk is in effect for the Southeast on Friday for rain totals in excess of 1". From the Midwest to the Southwest, lingering surface boundaries combined with a moist airmass, as well as the cold front progressing south, will lead to continued chances of rain and thunderstorms along with the risk for flash flooding. A Slight Risk of excessive rainfall is in effect through Thursday morning stretching from the Ohio Valley west through the Mid-Mississippi valley to southeastern Kansas. Heavy rainfall rates greater than 1" per hour are possible with any storms. While the rain may not be as heavy on Thursday, a Marginal Risk for excessive rainfall is in effect from the Mid-Mississippi Valley west through Oklahoma and into the Central High Plains due to the saturated soil conditions in place from the prolonged daily rainfall. Meanwhile, heavy rain will be possible with daily showers and thunderstorms in the Desert Southwest as moisture from the remnants of Tropical Storm Enrique continues northward into the region. A Marginal Risk of excessive rainfall is in effect for both Wednesday night and Thursday. Rain chances continue into Friday as the cold front stalls along the Southern High Plains, with a Marginal Risk for excessive rainfall in effect for most of eastern New Mexico and portions of the western Texas. Elsewhere, showers and thunderstorms are possible over the Great Basin and Central Rockies on Thursday and throughout the forecast period along the Gulf Coast and in Florida. Putnam Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php