Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 351 PM EDT Wed Jun 02 2021 Valid 00Z Thu Jun 03 2021 - 00Z Sat Jun 05 2021 ...Record-breaking heat found across the western United States to spread into the Northern Plains by Thursday... ...There is a Slight Risk of severe thunderstorms over west-central Texas through Thursday morning; there is a Slight Risk of severe thunderstorms over the Mid-Atlantic on Thursday into Friday morning... Strong upper-level ridging over the western U.S. will produce record-breaking heat from the Southwest to the Pacific Northwest. High temperatures will reach the upper-90s and triple digits across a broad spanning region from the Desert Southwest to the Northern High Plains. The largest temperature anomalies across the interior sections of the Pacific Northwest, where high temperatures will be near 30 degrees above the average high for this time of year. Excessive Heat Warnings and Heat Advisories stretch from Southern California to Northern Washington and Idaho. Extreme heat in these locations will significantly increase the potential for heat-related illnesses. Additionally, much of the Southwest and West are experiencing severe to exceptional drought conditions, contributing to the current heatwave. A weak cold front is expected to reach the Pacific Northwest by Thursday evening and offer some relief, along with a few isolated showers and thunderstorms. As the upper-level ridge slowly slides eastward, well above average temperatures will spread into the Northern Plains by Friday. Upper-level energy over the Southern High Plains will produce showers and thunderstorms may interrupt outdoor activities both Wednesday and Thursday. The SPC has issued a Slight Risk of severe thunderstorms over west-central Texas through Thursday morning. The main hazards associated with the severe thunderstorms are frequent lightning, severe thunderstorm wind gust, and hail. The severe thunderstorm threat shifts to the Mid-Atlantic on Thursday into Friday morning as a weak area of low pressure over the Lower Mississippi Valley swings northeast into the Lower Great Lakes by Thursday. Meanwhile, an associated warm front to its east will lift northward and usher in warm and humid air to nearly the East Coast. Thunderstorms will also form along a slow-moving cold front trailing the system from the Ohio and Tennessee valleys to southern Texas. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php