891 FXUS21 KWNC 291754 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT March 29 2026 SYNOPSIS: A progressive spring pattern is forecast during the second week of April. A frontal system is exiting the East Coast early in week-2 but not before bringing a heavy precipitation threat to parts of the southeastern contiguous U.S. (CONUS). Following the front, a quick chance of below normal temperatures is possible across parts of the eastern U.S. but by the middle of week-2, southerly flow will bring increased chances for warmer temperatures and heavy precipitation to parts of the Southern Plains and Mississippi Valley. HAZARDS Slight risk of heavy precipitation for portions of the Southeast, Mid-Atlantic, and adjacent areas, Mon, Apr 6. Slight risk of heavy precipitation for portions of the Southern Plains, Middle and Lower Mississippi Valley and adjacent areas, Fri-Sun, Apr 10-12. DETAILED SUMMARY FOR WEDNESDAY APRIL 01 - SUNDAY APRIL 05: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR MONDAY APRIL 06 - SUNDAY APRIL 12: By the outset of week-2, dynamical model 500-hPa height anomaly forecasts from the GEFS and ECMWF ensembles favor mid-level troughing over the eastern U.S. bookended by a pair of anomalous ridge centers situated over the western CONUS and off the Canadian Maritimes. A mean surface boundary is forecast over the southern Mid-Atlantic into the Southeast. Behind this boundary, ensemble guidance is in better agreement for mean long-wave troughing to remain in place for a few days before there is wider spread by the second half of week-2. Both ensemble means indicate progressive mid-level ridging to develop over the western CONUS early in week-2 before moving east with time. This increases chances for above-normal temperatures but at this time does not appear to approach widespread record breaking temperatures as the West has experienced the past couple of weeks. By the middle of the period, the ECENS indicates positive anomalies across much of the CONUS, while the GEFS maintains a more compact ridge over the central CONUS. Both tools indicate the potential for additional troughing to move into the West and then central CONUS at the end of week-2. Tied to the predicted frontal system across the East early in week-2, Probabilistic Extremes Tools (PETs) and uncalibrated precipitation guidance support a slight risk of heavy precipitation from the Carolinas through the Southeast. Tools generally indicate a 20-30% chance of precipitation exceeding 1 inch across this region, mostly falling on day 8. Therefore, a slight risk of heavy precipitation is posted for this area. Thunderstorm activity remains a threat within the highlighted risk area. The favored troughing and accompanying mean surface high pressure in the wake of the front is anticipated to bring colder temperatures across the central and eastern CONUS. With the deeper troughing favored in the GEFS over the eastern U.S., the GEFS PET features increased chances for minimum temperatures falling below the 15th percentile across much of the eastern CONUS as the mean surface high settles east of the Mississippi towards the middle of week-2. However, the ECENS PET and uncalibrated guidance maintain less anomalous temperatures. The week-2 Extended Range Temperature Forecast indicates above normal temperatures for the week-2 period as a whole. One or two days of anomalous frosts or freezes can not be ruled out over the eastern U.S. but there is too much uncertainty at this time to indicate a hazard. Across Hawaii, persistent Kona Low activity brought heavy rainfall and flooding to the state during mid-March. Guidance shows a return to a more seasonable trade wind regime, and although above-normal precipitation is favored, any heavy precipitation risk looks to be kept to the south closer to the equator in the PETs, at least through the middle of week-2. FORECASTER: Ryan Bolt $$