Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 437 PM EDT Tue Jun 29 2021 Valid 00Z Wed Jun 30 2021 - 00Z Fri Jul 02 2021 ...Historic heat wave continues across interior sections of the Northwest and Northern Rockies... ...A series of fronts will be the focus for ongoing heavy rain and the risk for flooding across the central U.S.... ...Heat continues for the Mid-Atlantic and Northeast ahead of a cold front bringing rain and severe weather chances Wednesday and Thursday... The unprecedented heat wave continues today for the interior Northwest and Northern Rockies, although the temperatures have peaked for most places. A cold front overnight brought some relief to the Portland/Seattle urban corridor and the focus for the hottest temperatures has shifted into eastern Washington and Oregon as well as western Idaho. The stagnant upper-level high pressure in place over the region will also begin to shift to the east over the next couple of days. Highs approaching 110 are likely Wednesday but will be closer to 100 on Thursday. Excessive Heat Warnings remain in effect for the region. An Excessive Heat Watch is in place over eastern Montana for Thursday as the heat shifts to the east with the upper-level high. A lingering surface front will remain in place today across the Midwest and Central/Southern Plains ahead of back to back cold fronts that will move into the region on Wednesday and Thursday. These fronts will be the focus for continued heavy rain and thunderstorms along with the risk for flooding. A Slight Risk of excessive rainfall is in effect for portions of Oklahoma, Kansas, and Missouri both today and Wednesday with daily rainfall totals between 1 to 3" possible. A more widespread Marginal Risk oriented from the northeast to the southwest is also in place for each day of the period to cover heavy rain and storm chances along the length of the fronts. Hot weather will also continue today and tomorrow for the Mid-Atlantic and Northeast with afternoon highs in the mid to upper 90s likely. Unfortunately, the heat is also combined with humidity across the region leading to temperatures that feel above 100. Widespread heat-related advisories are in place through Wednesday. A cold front will approach from the northwest during the day Wednesday, which combined with the moist and buoyant airmass will lead to the chance for severe thunderstorms. The Storm Prediction Center has issued an Enhanced Risk for severe weather for portions of east-central New York east into Massachusetts, with a broader Slight Risk in place from central Pennsylvania northeast into coastal Maine. High winds are the most likely threat from the severe weather, but some hail is also possible. The cold front will begin to move through the region on Thursday with continued rain and thunderstorm chances ahead of the front along the coast southwest into the southern Appalachians. Marginal Risks for excessive rainfall are in place for the chance of heavy rain with some of the storms, although the threat for more significant rainfall will likely hold off until Thursday night after the end of the current period. Behind the front, temperatures will drop below normal for this time of year, with 70s likely for the higher terrain and interior portions of the area. Elsewhere, daily rain and thunderstorm chances will continue across the south, stretching from Florida west through the Gulf Coast, Texas, and into the Desert Southwest. Temperatures will be around or even below normal and relatively comfortable for this time of Summer, with highs mostly in the 80s. Putnam Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php