Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 401 PM EDT Tue Jun 01 2021 Valid 00Z Wed Jun 02 2021 - 00Z Fri Jun 04 2021 ...Record-breaking heat found across the western United States through Thursday... ...Flash flooding across portions of the Lower Mississippi Valley through Wednesday morning... The western United States high temperatures are forecast to soar well above average from the Desert Southwest to the Pacific Northwest as upper-level ridging develops over the west through Thursday. Highs are expected to reach into the triple digits across the Sacramento and San Joaquin valleys of California and portions of southwest Oregon and the Desert Southwest. High temperatures into the 90s should spread as far north as central Washington and potentially north-central Montana on Wednesday. Excessive Heat Warnings and Heat Advisories are issued for areas where heat-related illness is possible if simple precautions are not taken over parts of California and Nevada. Farther east, a weak area of low pressure over northeast Texas is forecast to move east-northeast, entering the Ohio Valley by Thursday morning slowly. Showers and thunderstorms will develop along and ahead of an associated cold front as in influx of moisture streams northward from the Gulf of Mexico. Flash flooding will remain a concern on Tuesday across the Lower Mississippi Valley through Wednesday morning. WPC has issued a Slight Risk of Excessive rainfall that stretches from southern Missouri to Louisiana. Urban areas, roads, and small streams are most vulnerable to flash flooding. By Wednesday, showers and thunderstorms are forecast to shift into the Ohio and Tennessee valleys while also lingering throughout central and southern Texas. By Thursday morning, the showers and thunderstorms will move into parts of the Mid-Atlantic and the Southeast. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php