Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 249 PM EDT Wed Jul 23 2025 Valid 00Z Thu Jul 24 2025 - 00Z Sat Jul 26 2025 ...Approximately 107 million people under Extreme heat warnings and heat advisories from the Central Gulf coast to the Lower Lakes... ...Heavy rains, flash flooding and severe weather likely from the Central Plains into the Upper Mississippi Valley and Great Lakes... ...Heavy rains possible along much of the Gulf coast over the next few days... ...Relatively tranquil weather expected across the West, but a fire weather threat for northern California into the Great Basin due to lightning... The late July heat wave over the central to eastern U.S. will continue to produce a widespread region of major heat risks stretching from the Central Gulf coast, north through the Mississippi Valley, across the Ohio Valley and into the Lower Lakes region Thursday, pushing eastward by Friday across the megalopolis from Boston to New York City, Philadelphia, Baltimore and Washington D.C. The mid to upper level ridge anchoring this heat wave will continue to stretch from the eastern portions of the Southern Plains, east across the Lower Mississippi Valley, Ohio-Tennessee Valleys and into the Southern Mid-Atlantic, with this upper ridge likely to remain a dominant force going into this weekend and into next week. In the regions of high heat risks, Extreme Heat Warnings and Heat Advisories stretch across large portions of the mid section of the CONUS, through much of the Mississippi Valley, into the Lower Lakes. There is approximately 107 million people under these Extreme Heat Warnings and Heat Advisories, with this number likely to increase by Friday as the heat spreads back into the east coast urban corridor. While temperatures will be much above average in areas affected by this heat wave, there is not expected to be many records on Thursday, with a few more record or near record highs possible on Friday from Philadelphia into New York City and southern New England. There will, however, be a better chance of more widespread record high morning lows over the next several days stretching through the Mississippi Valley into the Great Lakes Thursday and Friday morning, shifting eastward toward the east coast Friday and Saturday mornings. Around the peripheries of the mid to upper level ridge, active thunderstorms, heavy rains, localized flooding and severe weather are possible as above average levels of moisture are expected to persist. Areas from the Central Plains into the Upper Mississippi Valley and Great Lakes will likely see the most active and widespread showers and thunderstorms over the next few days in the vicinity of a well defined frontal boundary pushing east southeastward. Ongoing organized thunderstorm activity over Minnesota and Wisconsin this afternoon will expand southwestward late this afternoon into this evening/overnight hours across the Central Plains. Another round of organized thunderstorms are again likely Thursday afternoon into early Friday morning along this front from the Central-Southern Plains into the Lower Missouri Valley and Middle Mississippi Valleys. With both episodes of organized thunderstorms, heavy rains, localized flash flooding and severe thunderstorms are possible. Currently flood watches are in effect across northern Minnesota into far northwest Wisconsin, affecting approximately 1 million people. A wet weather pattern will also persist over the next few days on the southeast side of the mid to upper level ridge from Florida, west along much of the Gulf coast. This wet weather is being driven by a series of mid to upper level disturbances that are pushing westward on the south side of the clockwise flow around the mid to upper level high to the north of the Gulf coast. Heavy rains and localized flooding possible across these areas, especially in the more urbanized regions. While the central to eastern CONUS will experience very active weather over the next few days from heat and thunderstorms, relatively quieter weather on tap for much of the West. Temperatures will remain below average heading into the later part of the work week from California, eastward into the Great Basin and Desert Southwest. Scattered showers and thunderstorms possible from the Southern High Plains into the Southern to Central Rockies, with isolated flash flooding possible over recent burn scar regions. Scattered showers and thunderstorms also possible across northern California, northwest Nevada, far southeast Oregon and far southwest Idaho to the east of a slow moving upper low pushing off the eastern Pacific and into the central California coast. While these storms are not expected to produce widespread heavy precipitation, lighting from the storms may ignite wild fires across these areas. Fire weather watches are currently in effect across northern California into southern Oregon. Oravec Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php