047 FXUS02 KWBC 161833 PMDEPD Extended Forecast Discussion NWS Weather Prediction Center College Park MD 233 PM EDT Thu Jul 16 2026 Valid 12Z Sun Jul 19 2026 - 12Z Thu Jul 23 2026 ...Dangerous heat will gradually subside in the north-central U.S. early next week... ...Overview... An upper ridge over the western and central U.S. into Sunday will continue to cause dangerous heat across the northern/central Plains. The northeast side of the ridge will get gradually suppressed by shortwave energy entering the Midwest/Great Lakes into a northeastern U.S. upper trough, which will bring relief from the heat to northern areas as the trough pushes cold fronts through the region. The shortwaves and fronts in the broader trough should also yield rounds of rain and thunderstorms in the Great Lakes to East Coast next week. Additionally, ample monsoonal moisture will continue to stream into the Southwest and Intermountain West, producing rounds of showers and thunderstorms. ...Guidance/Predictability Assessment... Model guidance is generally still agreeable on the large scale pattern, but some uncertainty lingers with the details especially late period. This mostly surrounds a shortwave rounding the top of the central U.S. ridge into the Great Lakes early next week, which will act to deepen the Eastern trough and push the upper ridge axis westward a bit into the Intermountain West. The ECMWF is notably stronger/sharper with this shortwave by mid next week over the Northeast, while the better consensus is more shallow with the surface low displaced more northward. Uncertainty also is present along the Northwest coast as troughing tries to move into the region late period. Plenty of uncertainty in the northeast Gulf with potential development of a tropical low. Recent guidance continues to be relatively weak with the low, and if it develops true tropical characteristics, it would be more towards the end of the short range period. Regardless, there is better confidence for some reflection of the low or an elongated trough over the Southeast to enhance rain across parts of Florida and the Southeast. NHC continues to track this with low probabilities of formation. The WPC forecast was based on a multi-model blend early in the period, with increasing proportions of the ensemble means (and less of the ECMWF) by Day 7. ...Weather/Hazards Highlights... Another hot day is in store Sunday for the northern/central Plains, as temperatures near/exceed 100F, yielding Major to isolated Extreme HeatRisk. WPC continues to update Heat Key Messages for this event, which can be found on our homepage. The ridge influence farther south will also lead to generally Major HeatRisk stretching into the central Plains and Middle/Lower Mississippi Valley to Southeast. The hot conditions should slowly ease in the northern states into the workweek, but be maintained in the south. Temperatures a few degrees above already warm averages combined with high humidity could lead to increased HeatRisk in the south-central U.S. and Gulf Coast states. 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 are in place from the Southwest across much of the Intermountain West for Day 4-5 (Sunday-Monday). Coverage of showers and thunderstorms should gradually increase eastward over the Rockies and High Plains early to midweek. Elsewhere, southern stream energy is forecast to meander in the northeastern Gulf in a moist and unstable environment early next week. Troughing and tropical moisture in place (even if there is no true tropical low) could lead to heavy rain, and Marginal Risks are in place for portions of northern/central Florida for isolated flash flooding on Sunday and Monday. Meanwhile the tail end of a frontal boundary could hang up in eastern North Carolina and Virginia and produce locally heavy rain on Sunday. The next round of rain and thunderstorms is forecast to come through the Midwest and Great Lakes early next week underneath a shortwave aloft. As the shortwave and front move southeast, rain chances should overspread much of the eastern U.S. for Tuesday-Wednesday. 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 $$