481 FXUS21 KWNC 011801 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT August 01 2026 SYNOPSIS: A persistent and moderately strong area of mid-level high pressure favors above-normal temperatures for nearly the entire Contiguous U.S. (CONUS) during early to mid-August. The West, Central to Southern Great Plains, and Southeast have an elevated chance of extreme heat. Antecedent dryness along with the likelihood of above-normal temperatures and below-normal precipitation during the next two weeks supports an increased risk for the Rapid Onset of Drought to parts of the Central to Southern Great Plains and Ozarks region. An enhanced Monsoon is forecast which increases the chance of heavy precipitation and flash flooding from the Desert Southwest north to the Central Rockies. HAZARDS Moderate risk of extreme heat for parts of California, the Great Basin, and Southwest, Sun-Mon, Aug 9-10. Moderate risk of extreme heat for much of the Central to Southern Great Plains and Middle to Lower Mississippi Valley, Sun-Sat, Aug 9-15. Slight risk of extreme heat for most of the CONUS excluding the Great Lakes region, Northeast, and Appalachians, Sun-Sat, Aug 9-15. Slight risk of heavy precipitation for the Desert Southwest and Four Corners region, Sun-Sat, Aug 9-15. Slight risk of heavy precipitation for the Midwest and Central Appalachians, Sun-Wed, Aug 9-12. Increased risk for Rapid Onset Drought (ROD) across parts of the Central to Southern Great Plains and Ozarks region. DETAILED SUMMARY FOR TUESDAY AUGUST 04 - SATURDAY AUGUST 08: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR SUNDAY AUGUST 09 - SATURDAY AUGUST 15: The GEFS and ECENS are in good agreement that a broad and moderately strong 500-hPa ridge persists over the southern two-thirds of the CONUS through mid-August. Compared to the beginning of the month, these ensemble means depict a slightly weaker ridge (500-hPa heights below 597 dm) but there remains either a slight or moderate risk of extreme heat for much of the West, Central to Southern Great Plains, and Southeast from Aug 9 to 15. A moderate risk of extreme heat, valid Aug 9 and 10, is posted for parts of California and the Great Basin where the NWS HeatRisk tool indicates more than a 40 percent chance of reaching the major HeatRisk category. Also, a consensus of the GEFS and ECENS Probabilistic Extremes Tools (PETs) generally depict that maximum temperatures have at least a 40 percent chance of exceeding the 85th percentile. Maximum temperatures are expected to reach 100 Deg F in the lower elevations of the Great Basin and 110 Deg F in southern Nevada and southeastern California. To the east of the Continental Divide, a moderate risk of extreme heat continues for the entirety of the week-2 period as the GEFS and ECENS show a strengthening ridge with time. The moderate risk area includes much of the Central and Southern Great Plains east to the Middle and Lower Mississippi Valley where ensemble means indicate temperature anomalies of 5-10+ Deg F above normal. Maximum heat index values are forecast to range from 100-105 Deg F in the Central Great Plains to 105-110 Deg F in the Southern Great Plains and Middle to Lower Mississippi Valley. The persistence of the anomalous 500-hPa ridge supports a slight risk of extreme heat for a majority of the CONUS through the end of week-2, Aug 15. Anomalously warm temperatures and drier-than-normal conditions are expected to maintain an elevated wildfire danger across the Northern Intermountain West through mid-August. By Aug 9th, the ensemble mean solutions remain consistent that the 500-hPa ridge axis becomes centered over the Four Corners region which is a favorable setup for an enhanced Monsoon. In addition, a weakening ridge aloft should allow for more widespread convection. The predicted 500-hPa height pattern along with the GEFS and ECENS PETs (> 20% chance of 3-day amounts exceeding the 85th percentile) support a slight risk of heavy precipitation across the Desert Southwest from Aug 9 to 15. Based on 24-hour amounts from the uncalibrated GEFS and ECENS, the slight risk of heavy precipitation was extended north to the Central Rockies. Any locally heavy rainfall could trigger flash flooding, especially in burn scar areas. Multi-model ensemble means agree that a 500-hPa trough shifts east near the Great Lakes which favors mesoscale convective systems (MCS) to track southeastward across the Midwest. Given the very humid airmass, any MCS will be capable of producing flash flooding. Pattern recognition and 1 to 3-day precipitation amounts from the GEFS and ECENS were used as guides to define a slight risk of heavy precipitation. It is valid through Aug 12th until 500-hPa heights begin to rise across the east-central CONUS. A Rapid Onset Drought (ROD) risk is designated for parts of the Central and Southern Plains along with the Ozarks region where 30-day precipitation deficits are greater than 2 inches and continued dryness and heat are forecast through early to mid-August. FORECASTER: Brad Pugh $$