Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 352 PM EDT Sun Jul 18 2021 Valid 00Z Mon Jul 19 2021 - 00Z Wed Jul 21 2021 ...There is a Slight Risk of excessive rainfall over parts of the Northeast, Lower Mississippi Valley, and Southern Rockies/Southwest through Monday morning... ...Excessive heat continues across the Northern Plains and Northern Great Basin... ...Potential for dry lightning over Central and Northern California could lead to conditions capable of producing wildfires... Low pressure over New England and associated slow-moving cold front will produce scattered thunderstorms and heavy rain through Monday morning. Therefore, the WPC has issued a Slight Risk of excessive rainfall with these thunderstorms. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams being the most vulnerable through Monday morning. The front over the southern parts of the country will become quasi-stationary through Tuesday evening. Showers and thunderstorms will develop along and near the boundary from the Southeast to parts of the Central/Southern Plains, as moisture pools along the front. The WPC has issued a Slight Risk of excessive rainfall with these thunderstorms. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable through Monday morning. On Monday, the excessive rainfall threat moves to the Southeast Coast and over parts of the Southern Plains/Lower Mississippi Valley. Meanwhile, monsoon moisture will stream into the Southwest and the Southern Rockies through Tuesday. The WPC has issued a Slight Risk of excessive rainfall with these thunderstorms. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams being the most vulnerable through Monday morning. Sections of central New Mexico are under Flash Flood Watches. High temperatures will continue into the triple digits are across eastern Montana, where a few daily high-temperature records could be tied or broken. Furthermore, the low temperatures are forecast to only drop into the 70s at night, making it harder to recover from the heat after sunset. Additionally, Excessive Heat Warnings and Heat Advisories have been issued over the Intermountain West. Residents are advised to drink plenty of fluids and avoid extended time outdoors to avoid heat-related illness. Parts of California have Fire Weather Watches and Red Flag Warnings over the area. Dry lightning could be a concern for Northern and Central California as monsoonal moisture enters from the south but produces very little rain. If thunderstorms do form, extremely dry fuels struck by lightning could produce new fires. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php