657 FXUS02 KWBC 021942 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 342 PM EDT Thu Jul 2 2026 Valid 12Z Sun Jul 05 2026 - 12Z Thu Jul 09 2026 ...Major Heatwave to settle over the South/Southeast next week... ...Pattern Overview... The strong upper ridge supporting a significant and dangerous heat wave heading through the holiday weekend should flatten into next week, however hazardous heat may still continue through Sunday for parts of the Ohio Valley into the East, lingering next week for the South/Southeast while also building into the Southwest. Meanwhile, a still broadly moist and unstable summertime airmass will broadly fuel warm sector showers and locally heavier thunderstorms storms over mainly the eastern 2/3rds of the country as enhanced by boundaries and as a series of hard to time impulses ride overtop the ridge. SPC offers a Mid-Atlantic severe weather threat Sunday. ...Guidance/Predictability Assessment... Guidance solutions remain reasonably well clustered at mid-larger scales. Most of the model, ensemble and machine learning guidance issues remain at smaller scales and especially with convective focus, albeit within generally similar but broad areas of concern. A guidance blend favoring the models Sunday/Monday and then the ensemble means and machine learning guidance onward next week seems to best mitigate smaller scale variances as consistent with individual feature predictabillity that lowers over time. ...Weather/Hazards Highlights... A major ongoing heat wave over much of the Midwest into the East should finally be lessening by the start of the period. Though not as hot as the short range, temperatures may still remain well above normal into Sunday for parts of the Ohio Valley into the East. Maximum temperatures into Sunday may still approach the 90s to low 100s for some, but are more uncertain and possibly could be restricted by increasing clouds/convection as the ridge breakdown continues. HeatRisk continues to remain in the Major to Extreme category into Sunday though, with Major to localized Extreme even persisting longer across the South/Southeast. Rain and thunderstorms should expand in coverage boradly across portions of the eastern 2/3rds of the nation this weekend within a very warm, moist, and unstable air mass. Fairly weak overall flow may also help to support at least a localized flash flood threat across much of this region, with possibly some better convection focus near a wavy frontal boundary into the Mid-Atlantic and Northeast. Favorable guidance trends have prompted introduction of a WPC Excessive Rainfall Outlook Day 4/Sunday Slight Risk Threat Area for the northern Mid-Atlantic. Broader Marginal Risk areas remain in place Sunday and Monday given potential from the Mid- South and Ohio Valley Region to the Mid-Atlantic and vicinity. Elsewhere, diurnally driven showers and storms are expected from parts of the central Gulf Coast to Florida most of the period with increasing moisture. Showers may refire again for parts of the Southern/Central Rockies and High Plains, as well as the northern tier ahead of additional shortwave energy. The rest of the West looks to remain mostly dry over this forecast period. Santorelli/Schichtel 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 $$