Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 343 AM EDT Thu Jun 03 2021 Valid 12Z Thu Jun 03 2021 - 12Z Sat Jun 05 2021 ...Record-breaking heat found across the western United States and Northern Plains... ...Severe weather and scattered flash flooding possible across the Northeast and Mid-Atlantic today... ...Additional chances for thunderstorms and heavy rain to linger across southern Texas and Louisiana through the weekend... A few more days of potentially record-breaking heat is in store for the West Coast and Intermountain West before the bulk of the well above normal temperatures shift into the northern tier states. A strong upper-level ridge responsible for the blistering early-season heat is currently located over the Great Basin and Northern Rockies. This ridge will slowly weaken on Friday and early this weekend, while shifting into the Northern Plains. Thus, well above average temperatures are forecast to spread into the Northern High Plains today and the rest of the Northern Plains and Upper Midwest on Friday. Widespread high temperatures in the upper-90s and low triple digits will be found across a large area to end the week, stretching from the Southwest, throughout much of the Intermountain West/Northern Rockies, and into the Northern Plains and Upper Midwest. Temperatures this hot can significantly increase the potential for heat-related illnesses. Scattered Excessive Heat Warnings and Heat Advisories have been issued for California and the Southwest, as well as the northern/central Great Basin. Much of this region happens to also be in the middle of extreme or exceptional drought conditions, which will be exacerbated by the ongoing heat. A cold front entering the Pacific Northwest today will offer much cooler temperatures by this weekend for sections of Washington, Oregon, and Idaho. This frontal boundary may also lead to scattered thunderstorms throughout the Northern Great Basin today and northern High Plains on Friday. For the eastern and south-central United States, a warm and humid airmass in place will lead to scattered showers and thunderstorms from the Northeast to the western Gulf Coast. High pressure located in the western Atlantic will continue to funnel southerly winds and ample moisture up the eastern third of the country, with a weak cold front located across the Ohio and Tennessee valleys to help spark thunderstorm activity. A few severe thunderstorms are possible today across the Mid-Atlantic and Northeast, with damaging wind gusts and isolated tornadoes possible. The Storm Prediction Center has issued a slight risk for severe weather (level 2/5) that extends from southern New York to central Virginia. Along with the severe thunderstorm threat, a few storms may produce heavy rain for an extended period of time, which could lead to instances of flash flooding. WPC has highlighted two areas with the highest probabilities for flash flooding. A Slight Risk of Excessive Rainfall (level 2/4) has been issued for sections of Upstate New York and southern Vermont, as well as southeast Virginia and the eastern Carolinas. Further south, linger precipitation will also be found across portions of Louisiana and southern Texas. This section of the country has experienced a plethora of rainfall over the last month, which has made ground conditions susceptible for flash flooding. Due to this concern and the potential for an additional 1 to 3 inches of rain today across South Texas, WPC has issued Slight Risk of Excessive Rainfall for the region. Rain chances will continue into the early part of the weekend as well, thanks to a slow-moving upper level low located over the Lone Star State, but shower activity is expected to be more isolated in nature to end the workweek. Snell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php