086 FXUS21 KWNC 221819 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT May 22 2026 SYNOPSIS: Strong mid-level high pressure over central Canada and weak mid-level flow over the Contiguous U.S. (CONUS) favor a relatively quiet week-2 forecast from a hazards perspective. Widespread heavy precipitation during week-1 may cause flooding for portions of the Lower Mississippi Valley and East Texas, which has the potential to linger into the week-2 period. A lingering frontal boundary is favored to interact with moist subtropical air, bringing the potential for heavy precipitation to portions of Florida. HAZARDS Slight risk of heavy precipitation for much of the Florida Peninsula, Sat-Tue, May 30-Jun 2. Flooding possible for much of eastern Texas, portions of Oklahoma, Arkansas, Louisiana, and Mississippi. DETAILED SUMMARY FOR MONDAY MAY 25 - FRIDAY MAY 29: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR SATURDAY MAY 30 - FRIDAY JUNE 05: Multiple model ensemble solutions for 500-hPa height anomalies depict a high-latitude Omega block becoming established at the outset of week-2 with a high amplitude ridge centered over Manitoba and moderate troughing over the Gulf of Alaska and the Canadian Maritimes, while weak shortwave disturbances are indicated in the subtropics, a pattern reminiscent of El Nino forcing. It would be early for such forcing to emerge but ocean temperatures in the El Nino monitoring regions have risen dramatically over the last few months so a quick onset of forcing is not out of the question. Regardless of the source though, the high latitude blocking pattern favors relatively tranquil weather over the CONUS. Temperatures are strongly favored to be above normal over the Northern Plains, near the axis of the ridge, however maximum temperatures are not expected to exceed hazardous thresholds so no corresponding hazard is issued at this time. Model ensembles depict a weak frontal boundary lingering over the Gulf of America in the wake of active weather during week-1. This boundary and associated return flow is favored to interact with tropical moisture, resulting in potentially heavy precipitation across much of Florida. The Probabilistic Extremes Tools (PETs) from the ECMWF and GEFS both indicate at least a 20% chance of 3-day precipitation accumulations to exceed the 85th climatological percentile and at least 1 inch through the middle of week-2. Uncalibrated probabilities from both models are also very bullish, with the ECMWF indicating a 20-30% chance of 2 inch accumulations over 3 days early in the period for southern Florida. Therefore a slight risk of heavy precipitation is posted for most of the Florida Peninsula, valid May 30-Jun 2. Multiple rounds of potentially heavy rainfall are likely during week-1 and may trigger flooding; some watersheds are already beginning to rise in response to the large influx of surface water. Week-1 QPF forecasts from the Weather Prediction Center depict precipitation totals exceeding 3-5 inches from southeastern Texas northeastward into portions of Arkansas and Louisiana, and any continued heavy precipitation into week-2 supports the potential of continued river flooding. A flooding possible hazard remains posted for eastern Texas and much of the Lower Mississippi Valley, while portions of central Texas have been removed from this hazard in todays outlook. Locally heavy precipitation may trigger urban and flash flooding as well, and caution should always be exercised when approaching floodwaters. In Alaska, river ice breakup season is beginning to wind down, but portions of the Lower Yukon and 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: Danny Barandiaran $$