Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 219 PM EDT Tue Jun 24 2025 Valid 00Z Wed Jun 25 2025 - 00Z Fri Jun 27 2025 ...Extremely dangerous heat persists across the Midwest and East Coast... ...There is a moderate risk of excessive rainfall leading to flash flooding across much of central New Mexico today... ...Additional excessive rainfall and severe thunderstorm concerns from the Front Range to the Midwest... ...Fire danger is elevated across the Four Corners today... A very strong upper ridge remains centered over the middle half of the country generating dangerous heat and elevated humidity throughout the week; this while the associated "Ring of Fire" thunderstorm activity will exists along its western and northern periphery, bringing its own severe/flooding related risks. Extensive extreme heat warnings and/or heat advisories remain in affect and currently cover from the entire East Coast to Georgia across to northern LA/S AR and up along the Mississippi Valley to about the IA/IL state and then south of the Great Lakes affecting nearly half of the U.S. population at 161 million people. Today, the East Coast to the Carolinas have the most extreme temperatures with numerous daily records already have fallen given temperatures in the lower 100s, combine that with dewpoints in the 70s to near 80s...heat indices will reach 115-125 degrees. While this will reduce in coverage and intensity tomorrow into the 90s, the overnight lows will not drop significantly with a vast area of lows remaining at or above 75 degrees which could be a record across the southeast, upper Ohio Valley and into the East Coast. Given the large urban area affected there will be significant cumulative heat impacts across the Mid-Atlantic into the Northeast through mid-week. This will exacerbate the heat health impacts especially by midweek. This level of heat can be dangerous to anyone without adequate cooling and/or hydration. Heat related illnesses increase significantly during long duration heat waves such as this. Take action when you see symptoms of heat exhaustion and heat stroke. A cold front will bring added relief toward Thursday into Friday across the northeast and Mid-Atlantic; the Ohio/Tennessee Valleys will remain in the major category for HeatRisk through the remainder of the week. Along the base of the large scale ridge, sub-tropical to tropical moisture out of the Gulf with some even being pulled across northern Old Mexico will increase the potential for numerous rounds of thunderstorms across New Mexico and across the Central Plains into the Midwest acting as the 'Ring of Fire' of stronger thunderstorm activity. Today is the best overlap of ingredients for significant heavy rainfall across New Mexico, where there remains a Moderate Risk of Excessive Rainfall (level 3 of 4) and broad Flood Watch is in affected for much of the state and far western portions of the West Texas Panhandle. Sensitive burn scar areas in the Sacramento Mountains are especially susceptible to flash flooding from heavy rainfall. Upslope areas of the southern Sangre de Cristo Mountains are also particularly vulnerable to flash flooding today. West of the moisture plume, stronger winds and drier conditions have an elevated risk (level 1 of 3) area of fire weather across the Grand Canyon, southern UT into far NW CO/S WY. Some modest mid-level cooler air near the stagnant frontal zone across the northern to central High Plains may support thunderstorm activity rising to Slight Risk (level 2 of 5) for severe risks of mainly hail and high winds, though an isolated tornado is possible. The risk of severe thunderstorms and scattered flash flooding extend eastward along the stationary front in NEB, IA into the Great Lakes and lesser so into the Interior northeast, with generally a category/risk level reduced by one. As the week progresses into Wednesday, the moisture and stronger mid-level energy will ride the ridge northward reducing the coverage of flash flooding potential to level 2 of 4, or Slight across NM and across the Upper Midwest, while the focus reduces to a Marginal Risk (1 of 5) for severe across the Central Plains to northeast. However, the sheer magnitude of heat/humidity over the East Coast under the ridge will result in an increased coverage of thunderstorm activity capable of producing severe winds across the Carolinas to the northeastern Gulf Coast. Thursday, the activity under the ridge will continue to be a Marginal Risk for severe weather; while the enhanced moisture flux continues into the Upper Midwest and Western Great Lakes with a Slight Risk of Excessive Rainfall/Flash flooding expected. Gallina Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php