428 FXUS21 KWNC 251807 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT May 25 2026 SYNOPSIS: Mid-level low pressure coupled with a stationary front increases the chance of heavy precipitation across parts of the Southeast, especially Florida, during the first week of June. A large area of mid-level high pressure is forecast to persist over the north-central contiguous U.S. (CONUS). By the beginning of June, this mid-level high pressure is predicted to expand southwestward and bring a warming trend to the western CONUS. The most likely areas to experience extreme heat would be the Central Valley of California and Desert Southwest from June 2 to 4. HAZARDS Moderate risk of heavy precipitation for Central and South Florida, Tue-Thu, June 2-4. Slight risk of heavy precipitation for parts of the Southeast, Tue-Fri, June 2-5. Slight risk of extreme heat for the Central Valley of California and Desert Southwest, Tue-Thu, June 2-4. DETAILED SUMMARY FOR THURSDAY MAY 28 - MONDAY JUNE 01: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR TUESDAY JUNE 02 - MONDAY JUNE 08: At the beginning of June, the GEFS and ECENS remain in good agreement with a highly amplified 500-hPa ridge extending from the north-central CONUS northward to Hudson Bay. Downstream of this strong mid-level ridge, a 500-hPa trough is forecast along the East Coast and western Atlantic. A cold front, associated with this trough aloft, is predicted to shift southward and become stationary near the Gulf Coast by early next week. This stationary front will enhance precipitation and a wave of low pressure may even develop along the front. Regardless of any surface low formation, the pattern is favorable for a very wet pattern across Florida due to deep tropical moisture and a weakness in the subtropical ridge. Therefore, a moderate risk of heavy precipitation is posted for the central and southern Florida Peninsula from June 2 to 4. This is supported by the uncalibrated ECENS which depicts that there is near a 40 percent chance of 3-day amounts to exceed 2 inches. A slight risk of heavy precipitation, valid through June 5, is designated for areas as far north as southeastern Alabama and southern Georgia based on 24-hour precipitation amounts from the GEFS and ECENS.Given the anomalous low to mid-level moisture and weak steering flow, any slow-moving thunderstorms would increase the risk of flash flooding. The transition from a dry La Nina pattern to a wetter regime would bring drought relief to the Southeast. According to the U.S. Drought Monitor valid May 19, three-quarters of Florida is designated with extreme (D3) to exceptional (D4) drought. An Omega block at 500-hPa over the middle to high latitudes of North America, northwestern Atlantic, and northeastern Pacific is forecast to persist from late May into the beginning of June. Prior to the start of week-2 (June 2), multi-model ensemble mean solutions favor a southwestward expansion of the central North American ridge with positive 500-hPa height anomalies (more than +60 meters) developing over the western CONUS. This predicted longwave pattern would bring a significant warming trend to this region heading into June. A slight risk of extreme heat (June 2 to 4) is posted for the Central Valley of California and Desert Southwest where the GEFS and ECENS PETs depict that there is a 20 to 40% chance that maximum temperatures exceed the 85th percentile along with 95 and 105 degrees F, respectively. Although above-normal temperatures are likely (>50% chance) for much of the Pacific Northwest, Northern Intermountain West, and Northern Great Plains during week-2, maximum temperatures are expected to remain below the threshold for extreme heat. The warmest temperatures (upper 80s to lower 90s) are forecast in the Snake River Valley of Idaho along with eastern portions of Oregon and Washington. In Alaska, river ice breakup season is ending, but many rivers north of the Brooks Range remain icebound. River breakup flooding can occur with little or no notice as conditions on frozen rivers can change quickly, so please check with the Alaska Pacific River Forecast Center for the latest conditions and advisories. FORECASTER: Brad Pugh $$