479 FXUS21 KWNC 161821 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT July 16 2026 SYNOPSIS: An area of mid-level high pressure over the south-central contiguous U.S. (CONUS) is forecast bringing elevated chances of extreme heat to the region. Further north, above normal temperatures bring a continued risk of Rapid Onset Drought to parts of the Northern Plains. Across the interior West, a slight chance of heavy precipitation associated with monsoon moisture is possible. Finally, a lingering boundary across the southeastern CONUS brings chances for heavy precipitation to parts of the Southeast and Mid-Atlantic. HAZARDS Moderate risk of extreme heat for parts of the Southern Plains and the Lower Mississippi Valley, Fri-Mon, Jul 24-27. Slight risk of extreme heat for parts of the Central and Southern Plains, Lower Mississippi and Tennessee Valleys, Southeast U.S., and Southwest, Fri-Thu, Jul 24-30. Slight risk of extreme heat for Interior Washington, and adjacent parts of Idaho and Oregon, Fri, Jul 24. Slight risk of heavy precipitation for much of the Southwest, Central Great Basin, and Central Rockies, Fri-Sun, Jul 24-26. Slight risk of heavy precipitation for parts of the lower Mid-Atlantic and Southeast, Fri-Sun, Jul 24-26. Rapid onset drought (ROD) possible for portions of the Dakotas. DETAILED SUMMARY FOR SUNDAY JULY 19 - THURSDAY JULY 23: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR FRIDAY JULY 24 - THURSDAY JULY 30: Multiple model ensembles depict anomalous mid-level ridging persisting over the western and central CONUS through much of week-2, with a closed 594-dm contour remaining near the Four Corners. There is increased support for a period of subtropical ridging to build into the south-central CONUS at the end of week-1 and into week-2. This particularly stands out in the normalized 500-hPa height anomalies where 1 to 2 standard deviation anomalies are forecast at the climatological peak of summer. Generally, southerly flow off the Gulf of America is favored to boost dewpoints east of the Rockies, resulting in potentially hazardous heat index values in parts of the Central and Southern Plains and Gulf Coast. Further west, temperature rises favored early in week-2 increases chances for extreme heat to develop across parts of the Southwest. The potential for extreme heat continues to be supported by a variety of forecast tools with elevated forecast confidence over parts of the Southern Plains and Lower Mississippi Valley. The GEFS-ECWMF combined extreme heat tool shows widespread 20 to 40% chances of either maximum temperatures or heat index values to exceed the 90th percentile at some point during the week-2 period for most of the CONUS except along the Northern Tier. Additionally, probabilities exceed 40% and as high as 60% for the same threshold across parts of Texas and the Lower Mississippi Valley. Given all this, a moderate risk of extreme heat is posted for parts of the Southern Plains and the Lower Mississippi Valley covering Jul 24-27. The lengthend valid period in the updated outlook is the result of better agreement for mid-level ridging to persist during week-2 across the region. A broader slight risk of extreme heat remains posted for much of Central and Southern Plains, Middle and Lower Mississippi Valley, Tennessee Valley, and Southeast for all of week-2. This slight risk is also expanded into the Southwest in today’s forecast. A slight risk of extreme heat remains posted for Interior Washington for Jul 24, consistent with increased signal from the extreme heat tools. Guidance from the uncalibrated and PET tools show elevated signals across the Pacific Northwest at the end of week-1 and into week-2. Above normal temperatures are likely to persist across the Northern Plains, although these temperatures are less likely to reach hazardous thresholds. However, the combination of anomalous warmth and dryness during week-1, combined with near to slightly above normal precipitation favored during week-2, and antecedent dryness supports an enhanced risk of Rapid Onset Drought (ROD) across portions of the Northern Plains. With mid-level ridging more strongly developing across the Four Corners by the early to middle part of week-2, there are decreasing signals for monsoonal moisture moving into the interior West. PETs have been slowly shunting the moisture signal further West and reducing the signal as well. Furthermore, the daily uncalibrated precipitation guidance is distinctly reduced relative to prior forecasts. Therefore, the moderate risks of heavy precipitation along with the flooding possible shapes are discontinued today. A slight risk remains posted for the first three days of the period. There could still be more scattered thunderstorms across the region and some support remains in the guidance. Monsoonal moisture can also produce dry lightning, resulting in increased wildfire risk where precipitation does not fall. A slight risk of heavy precipitation is forecast for parts of the Southeast Atlantic states and southern Mid-Atlantic for Jul 24-26. Models continue to support a lingering frontal boundary bringing elevated chances for heavy precipitation to the region early in week-2. Both the PETs and uncalibrated guidance bring at least 20% chances for three day precipitation amounts to exceed the 85th climatological percentile and 1 inch across the highlighted region. FORECASTER: Ryan Bolt $$