Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 351 AM EDT Thu Jul 24 2025 Valid 12Z Thu Jul 24 2025 - 12Z Sat Jul 26 2025 ...Approximately 130 million people are under Extreme Heat Warnings & Heat Advisories from the Central Plains to the Northeast.. ...Heavy rain, flash flooding, and severe weather likely from the Central Plains and Midwest to the Great Lakes... ...Heavy rain 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... A late July heat wave will continue to expand eastwards during the second half of the week with sultry conditions on tap from the Lower Mississippi Valley and Midwest to the Northeast and Mid-Atlantic. This is due to upper-level high pressure anchoring itself over the eastern U.S. that is acting as a heat dome over the eastern third of the Lower 48. Heat indices will generally top out somewhere between 100-105F from the Southern Plains, Midwest, and Great Lakes today to the Northeast and Mid-Atlantic by Friday with localized heat indices possibly approaching 110F. This has resulted in the issuance of numerous Heat Advisories in these regions today and Friday. In the Lower Mississippi Valley, oppressive heat indices of 105-110F with some localized pockets near 115F have resulted in Extreme Heat Warnings today. Record high temperatures are likely to be challenged in parts of the Northeast today and Friday, with all regions affected likely to see some record warm minimum temperatures broken as well. WPC continues to carry Key Messages for this ongoing heat wave, which also covers the return of stifling heat over the Midwest by this weekend. Please visit www.weather.gov/safety/heat for more information on tips for how to stay could and safe when dealing with dangerous heat. As the upper-level ridge of high pressure causes sizzling heat in the East, it will also help to usher in copious amounts of Gulf moisture northward across the Front Range of the Rockies, the Central Plains, and Midwest today. In addition, a cold front approaching from the Northern Plains will help ignite widespread thunderstorms across much of the Nation's Heartland and in to the Great Lakes. These storms will have an abundance of moisture at their disposal, with moisture content that has origins from the tropics. This has prompted the issuance of a Slight Risk (threat level 2/4) from the southern High Plains on east to the Chicagoland metro area today. The frontal boundary is not likely to make much progress on Friday, making it possible for similar parts of the Midwest that were hit with storms on Thursday could see additional strong storms on Friday. WPC maintains a Slight Risk from the Central Plains on east through the heart of the Midwest. In addition, some storms may potentially become severe. The Storm Prediction Center has a lengthy Marginal Risk (threat level 1/5) from the Rockies' Front Range to the Great Lakes. The severe threat on Friday moves into the Northeast with a Marginal Risk encompassing much of the Northeast's I-95 corridor. Additional severe storms are also possible in the Northern Plains on Friday ahead of another approaching cold front. In the South, a wave of low pressure moving west along the Gulf Coast containing tropical moisture aloft will spawn additional heavy showers and thunderstorms from the central Gulf Coast on east through much of Florida today. The heavy rain potential continues to march west towards the Texas Coast on Friday with additional downpours likely along the Gulf Coast. Some locally heavy thunderstorms are possible as far north as the Carolinas today thanks to a nearby frontal boundary. WPC is carrying a Marginal Risk (threat level 1/4) from the central Gulf Coast to the coastal Carolinas today, while Friday sports a Marginal Risk once again along the central Gulf Coast and the Upper Texas Coast on Friday. While the majority of the West is likely to experience dry and seasonally cool conditions, the exception to the dry conditions is northern California on east into the northern Great Basin. A cut-off upper low will direct moisture at the region with scattered thunderstorms likely to develop. Dry thunderstorms are a growing concern in the northern Sierra Nevada and into the northern Great Basin where critically dry fuels are present and lightning strikes could spark wildfires in these regions today. SPC highlights the northern Sierra Nevada as having the better odds of witnessing dry thunderstorms today. The dry thunderstorm potential becomes more isolated in nature on Friday, but the wildfire potential persists from the northern Sierra Nevada to as far north as Idaho's Snake River Valley. Mullinax Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php