236 FXUS02 KWBC 141845 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 245 PM EDT Tue Jul 14 2026 Valid 12Z Fri Jul 17 2026 - 12Z Tue Jul 21 2026 ...Dangerous heat continues across the north-central U.S. through the end of the week... ...Overview... A strong upper ridge over the central U.S. will continue to cause dangerous heat across the northern Plains and Midwest late week. The eastern portion of the ridge likely joining up with a subtropical Atlantic ridge should lead to hot temperatures across the Ohio Valley to Mid-Atlantic Friday as well. An upper trough poking into the Northeast should gradually shift the heat southward and bring some relief to northern areas over the weekend and early next week. Meanwhile, monsoonal moisture will continue to stream in underneath the upper ridge, producing rounds of diurnally driven showers and storms across the Southwest, Four Corners states, and northward into the northern Rockies/High Plains. Additionally, energies on the northern side of the ridge could also lead to rounds of rain and thunderstorms in the Great Lakes/Ohio Valley to East Coast. ...Guidance/Predictability Assessment... Model guidance has been reasonably agreeable on the large scale pattern, including the upper ridge in the Rockies to Plains and stretching into the southeastern U.S. as the period begins Friday. Troughing in the Northeast is forecast to gradually deepen over the weekend and early next week, which should push the upper ridge axis westward a bit into the Intermountain West. Uncertainty for the period seems to mostly be associated with various shortwaves rounding the top of the ridge into the Northeast, which drives the trough depth as well as QPF and frontal placement. Out West, a compact upper low looks to move inland into British Columbia around Saturday, and guidance continues to show better agreement on the speed of this system. The ECMWF is still slightly on the faster side of consensus, but is at least within the spread and usable in the WPC blend for today. Otherwise, there is still some signal especially from AIFS and ICON ensemble members and the AIGFS showing enhanced tropical moisture in the northeastern Gulf early next week, which bears watching. The WPC forecast was based on a blend of the deterministic guidance and AIFS through Day 5. After this, the guidance remained in good enough agreement for a 60/40 deterministic/ensemble mean blend for Days 6 and 7. Generally maintained good agreement with the previous WPC forecast as well. ...Weather/Hazards Highlights... Hazardous heat is forecast to persist in the north-central U.S. into late week under the upper ridge. Continued well above normal maximum and minimum temperatures will lead to Major to Extreme HeatRisk in the northern/central Plains and Midwest. WPC continues to update Heat Key Messages for this event, which can be found on our homepage. The hot conditions should slowly ease in the northern states and shift southward into early next week. Farther east, the upper ridge combining with subtropical Atlantic ridging in the Southeast and Florida will promote warmer than average temperatures as far north as the Ohio Valley and Mid-Atlantic Friday, also moving gradually southward through the period as the northeastern U.S. upper trough pushes a cold front or two slowly south. Meanwhile, the southwestern to south-central U.S. could see slightly below average temperatures as ample moisture leads to clouds and rain/thunderstorms. Continued southerly flow under the broad upper ridge will draw significant monsoonal moisture into the Southwest and Intermountain West to Rockies. This moisture will lead to scattered to numerous showers and thunderstorms with the potential to produce heavy rainfall and localized flash flooding. Sensitive places such as burn scars, steep terrain, etc., would be the most vulnerable to any flooding concerns that may develop. Broad Marginal Risks of excessive rainfall remain in place from the Southwest across parts of the Intermountain West north to Montana for Day 4-5 (Friday-Saturday). The Marginal also encompasses western Texas, which will likely have ample rainfall in the short range period causing extremely wet antecedent conditions. For Day 4/Friday, a Slight Risk is in place for much of Arizona and vicinity where enhanced rainfall and flooding threats are relatively more likely, with a slight risk also for western Texas where continued rains are expected following a very wet short range period. Monsoonal moisture should persist into early next week across the Southwest. Multiple rounds of rain/thunderstorms are also possible from the Great Lakes and Ohio Valley to the East Coast as shortwaves and frontal systems focus moisture through the period. Marginal Risks of flash flooding are delineated for the Great Lakes/Ohio Valley to Appalachians on Friday, and stretching into the Mid-Atlantic on Saturday. Santorelli/Tate Additional 3-7 Day Hazard information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range 500mb heights, surface systems, weather grids, quantitative precipitation forecast, excessive rainfall outlook, winter weather outlook probabilities, heat indices and Key Messages are at: https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml https://www.wpc.ncep.noaa.gov/#page=ero https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml https://www.wpc.ncep.noaa.gov/#page=ovw $$