848 FXUS02 KWBC 081932 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 332 PM EDT Wed Jul 8 2026 Valid 12Z Sat Jul 11 2026 - 12Z Wed Jul 15 2026 ...Major heatwaves impact portions of the Southeast and North- Central U.S. this weekend and early next week... ...Overview... A broad upper-level ridge expands and strengthens over the central U.S. this week, leading to a significant and dangerous heat wave across the northern Plains this weekend into next week. Major to extreme heat risk continues for the Southeast before waning as a cold front brings rounds of showers and storms. As the ridge moves into the central U.S., monsoonal moisture pushing into the Southwest will support increasing chances for showers and thunderstorms. ...Guidance/Predictability Assessment... The latest model guidance remains in fairly good agreement with its depiction of the large scale pattern through most of the medium range period. The pattern features an anomalously strong, broad, and expansive ridge from the western to the central U.S., flanking troughing along the West and East Coasts, and shortwaves riding over top of the ridge across southern Canada. Some spatial and timing differences exist with respect to the shortwave energy moving across southern Canada, with the GFS much faster than the ECMWF, CMC, and EC-AIFS. Overall, the WPC forecast utilized a blend of all available guidance for Day 3 before transitioning to mostly EC, CMC, and EC-AIFS for Days 4 through 7. For Days 6 and 7, 30 to 40% of the blend weighted towards the EPS, offering stability, maintaining continuity, and mitigating smaller scale differences. ...Weather/Hazards Highlights... Anomalously strong and sprawling upper-level ridging builds from the western to the central U.S. late this week, resulting in an extended period of well above average temperatures across parts of the Intermountain West, northern Plains, and Upper Midwest this weekend into early next week. Multiple days of widespread major to localized extreme heat risk will likely make for a dangerous heat wave across the region. Elsewhere, ridging in the Southeast will continue to foster major to isolated extreme heat risk through the weekend, with heat indices between 105-115 degrees. A deepening trough along the East Coast should bring some relief to the area by early next week, though hazardous heat is expected to persist across Florida through most of the period. A synoptic front pushing south through the Midwest, Tennessee Valley and Southeast will act as a focus for showers and thunderstorms beginning this weekend. Some storms may generate pockets of heavy rainfall that could lead to isolated instances of flash flooding. Increasing southerly flow around the western periphery of the central U.S. ridge will draw monsoonal moisture into the southern Four Corners and Great Basin later this weekend into early next week. This moisture will likely lead to the development of scattered to numerous showers and thunderstorms with the potential to produce heavy rainfall and localized flash flooding. Miller/Kebede 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 $$