292 FXUS02 KWBC 311943 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 343 PM EDT Fri Jul 31 2026 Valid 12Z Mon Aug 03 2026 - 12Z Fri Aug 07 2026 ...Heat wave likely to continue across the Southwest and Intermountain West into next week... ...Overview... The upper ridge dominating the weather pattern across the western half of the country will weaken slightly and get suppressed south early next week as a strong cold front is forecast to bring much cooler air through the Northwest and into the northern Plains the first half of the week. Meanwhile, a slowly dissipating front merging with a wave lifting from the Midwest to the Northeast will trigger scattered showers and thunderstorms, which will gradually edge toward the East Coast through much of the week. Excessive heat will be persistent across the southwestern quadrant of the country, and should gradually spread northeast into the central Rockies/Plains as the upper ridge re-intensifies, as well as farther east toward the Southeast as it could join with subtropical Atlantic ridging coming in for later week. ...Guidance/Predictability Assessment... Early next week even for Day 3-4, there is already a fair amount of model spread with the pattern in the eastern U.S., as vorticity placement within a trough leads to differences at the surface and aloft. The 12Z model guidance has converged somewhat though, showing an upper/surface low over the Ohio Valley by Tuesday, though AI models tended to be slightly weaker but farther south. Upstream, troughing across the Northwest early week will push east across the northern tier and likely broaden, with just some typical model differences in shortwave and frontal timing. Upper ridging is forecast to spread across the southern tier as the Southwest high broadens and subtropical Atlantic ridging expands west. This is broadly well handled by the dynamical and AI models. The WPC forecast used a multi-model blend early in the forecast period, with increasing proportions of the ensemble means mid to late period, though still maintaining over half deterministic models. This helps smooth out the bigger differences while maintaining good agreement with the previous WPC forecast as well. ...Weather/Hazards Highlights... Heat across much of the Intermountain West for the short range should be suppressed southward by Monday as a cold front sinks across the northern tier and brings below average temperatures to the northern Rockies/Plains. However, widespread Major to Extreme HeatRisk will continue for much of the Southwest through much of next week. Then, heat should build again gradually northward across the Intermountain West and Rockies to the High Plains, as well as eastward in the Mid-South and Southeast as the upper ridge expands. See Key Messages issued by WPC for this event for additional information regarding this long lasting and dangerous heat wave. Temperatures across the East should be generally near average. Showers and thunderstorms are expected to overspread the East Coast states into Monday as moisture is advected northward ahead of the eastern U.S. upper trough. Rainfall could be most impactful across portions of the northern Mid-Atlantic and Northeast, where a Slight Risk of excessive rainfall is in place. Rain and storms likely linger across the East ahead of the next trough into the Great Lakes mid to late next week. Elsewhere across the contiguous U.S., most of the monsoonal rainfall should be confined to eastern Arizona and into central New Mexico, with scattered convection reaching into portions of Utah and Colorado. A corridor of showers and storms is likely ahead of the front that crosses the Dakotas and into Minnesota early in the week, and this may also be accompanied with some severe weather. Heavy rain seems possible in the central Plains/Mid-Mississippi Valley into Tuesday-Wednesday with that front. Tate/Santorelli 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 $$