260 FXUS21 KWNC 131758 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT May 13 2026 SYNOPSIS: There continues to be significant disagreement among the GEFS and ECENS models regarding the anticipated pattern resulting in a fair amount of uncertainty regarding hazards. Mid-level high pressure is anticipated across the eastern Contiguous U.S. (CONUS) during week-2. The likelihood of temperatures reaching extreme heat criteria is anticipated to mostly occur during week-1, with some areas across the Carolinas and Virginia experiencing lingering heat at the onset of week-2. There are continued increased chances for extreme heat for the central valley of California at the beginning of the period, with mid-level high pressure potentially lingering across the region into the start of the period. Meanwhile, cyclonic mid-level flow over the southwestern CONUS may bring episodes of high winds across coastal California and Oregon. Possible surface lows across the Interior West and lee of the Rockies may support high winds in these regions. HAZARDS Slight risk of extreme heat for portions of Virginia and the Carolinas, Thu, May 21. Slight risk of extreme heat for the Central Valley of California, Thu-Fri, May 21-22. Slight risk of high winds for parts of the Interior West and Great Plains, Thu-Mon, May 21-25. Slight risk of high winds for much of coastal California and Oregon, Thu-Sat, May 21-23. DETAILED SUMMARY FOR SATURDAY MAY 16 - WEDNESDAY MAY 20: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR THURSDAY MAY 21 - WEDNESDAY MAY 27: Multiple models continue to favor ridging across the eastern CONUS expanding westward throughout week-2. Above normal temperatures are favored across much of the CONUS during week-2, with possible heat lingering from the end of week-1 into the beginning of week-2 over a portion of the East Coast. A slight risk of extreme heat is posted for portions of Virginia and the Carolinas May 21, where the ECENS Probabilistic Extremes Tool (PET) and uncalibrated guidance indicates at least a 20% chance of maximum temperatures exceeding the 85th percentile climatologically and 90 deg F. Across the West, there is significant uncertainty regarding the mid-level pattern, with the ECENS favoring positive mid-level height departures extending further into the West Coast from the Northeast Pacific and for a longer duration into week-2. On the flip side, the GEFS develops a trough across the West Coast early in the period translating to the ECENS having greater signals for anomalous warmth across the West Coast than the GEFS. Despite these differences, a slight risk of extreme heat is maintained for the central valley of California May 21-22, where temperatures may exceed the 85th percentile and 90 deg F. Uncalibrated ECENS forecast guidance continues to indicate increased chances of temperatures exceeding 100 deg F across the risk area on day 8 (May 21). Enhanced rainfall is possible across the central CONUS locally ahead of the mid-level trough across the West. However, due to significant differences in the models regarding these features, there is too much uncertainty to designate any areas with an associated heavy precipitation hazard at this time. Localized thunderstorms are possible across the Great Plains and Mississippi Valley that could lead to flash flooding. This trough could support surface low formation across the Interior West and in the lee of the Rockies. With adjacent surface high pressure possible across the West Coast and the East, tight pressure gradients may lead to episodes of high winds across the West. A broad area is highlighted with a slight risk of episodic high winds across portions of the Interior West and Great Plains, May 21-25. These areas are indicated as having at least a 20% chance of wind speeds exceeding the 85th percentile in the PETs and/or possible wind gusts exceeding 34 kts (~ 40 mph). Antecedent dry conditions combined with gusty conditions may support enhanced wildfire risk in some areas. The National Interagency Fire Center (NIFC) shows some areas in the Great Plains and Four Corners region having a moderate risk of significant fire potential at the end of week-1. A slight risk of high winds remains posted over portions of coastal California and Oregon May 21-23, where ensembles generally show cyclonic mid-level flow underneath the anomalous ridge center over the northeastern Pacific as well as periods of strengthening pressure gradients in the surface guidance. In Alaska, the typical peak of the river ice breakup season is approaching, and ice jam flooding can occur this time of year with little or no notice as conditions on frozen rivers can change quickly. Please check with the Alaska Pacific River Forecast Center for the latest conditions and advisories. FORECASTER: Melissa Ou $$