183 FXUS21 KWNC 141845 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT April 14 2026 SYNOPSIS: Low pressure aloft and at the surface over the High Plains supports the potential for episodes of high winds throughout many parts of the West, Great Plains, and Mississippi Valley, along with an elevated risk of heavy precipitation focused over the Lower and Middle Mississippi Valley. While many portions of the Southeast are increasingly favored to see near to above-normal precipitation during week-2, antecedent dryness combined with unseasonably warm temperatures and below-normal precipitation during week-1 increases the risk for Rapid Onset Drought and intensification of drought over parts of the southeastern U.S. Over the upper Midwest, flooding is possible associated with persistent above-normal precipitation accelerating spring snowmelt over the next two weeks. HAZARDS Moderate risk of heavy precipitation for portions of the Middle and Lower Mississippi, Tennessee and Ohio Valleys, Thu-Fri, Apr 23-24. Slight risk of heavy precipitation for portions of the Southern Plains, Mississippi, Tennessee, and Ohio Valleys, Wed-Sat, Apr 22-25. Slight risk of high winds for parts of the Great Basin, Southwest, Rockies, Great Plains, and Mississippi Valley, Wed-Sat, Apr 22-25. Possible flooding for parts of the Great Lakes region and Upper and Middle Mississippi Valley. Rapid Onset Drought risk across parts of Mississippi, Alabama, Georgia, and South Carolina. DETAILED SUMMARY FOR FRIDAY APRIL 17 - TUESDAY APRIL 21: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR WEDNESDAY APRIL 22 - TUESDAY APRIL 28: Multiple dynamical models continue to advertise a progressive mid-level height pattern during week-2. Downstream of a 500-hPa ridge over the northeastern Pacific, both the GEFS and ECMWF ensembles continue to feature cyclonic flow prevailing throughout the Interior West, with a narrow ridge axis focused across the Great Plains and Mississippi Valley early in week-2. Over time, ensembles have trended towards developing a more amplified mean troughing solution focused over the southwestern CONUS, while continuing to break down the ridging downstream east of the Rockies later next week. Further north, however, the most notable trend in the models concerns the development of an amplified ridge centered over the Davis Strait consistent with a negative North Atlantic Oscillation (-NAO) pattern. Such a pattern shift may be driven by a strengthening Madden-Julian Oscillation (MJO) in the western Pacific. While models favor much of the longwave troughing to develop over the western Atlantic late in the period, any persistence of a blocking high over northeastern Canada could allow a transition for cooler temperatures for much of the central and eastern CONUS later in April. Tied to the mid-level troughing favored over the interior West, surface low development is favored in the lee of the Rockies where both the GEFS and ECMWF have come into better agreement featuring a mean low center over western Nebraska and western Kansas by the outset of week-2. With mean surface high pressure favored to be established over the Southeast and Mid-Atlantic supporting enhanced lower-level moisture into parts of the Great Plains, Mississippi and Tennessee Valleys, the synoptic pattern looks more conducive for potentially heavy precipitation relative to yesterday. Based on an overall uptick in signals in the raw and calibrated precipitation tools, a moderate risk of heavy precipitation is posted for Apr 23-24 over the Lower and Middle Mississippi Valley and adjacent Mississippi-Ohio River confluence where the raw GEFS and ECMWF show at least 40% chances of 3-day precipitation amounts exceeding an inch. Despite this higher risk designation in the updated outlook, there continues to be added uncertainty in regards to whether this precipitation risk shifts eastward with time. The ECMWF ejects much of the shortwave troughing with wetter conditions unfolding over Southeast, whereas the GEFS maintains a more westerly solution of the mean troughing aloft resulting in a comparably drier picture for this part of the country. To reconcile these differences aloft and in the precipitation tools, a slight risk remains posted and is expanded slightly southeastward to include portions of the Southern Plains, Mississippi, Tennessee, and Ohio Valleys and also extended through Apr 25 where uncalibrated tools show lesser (20-40%) chances of 3-day amounts exceeding an inch through the middle of the period. Of note, accumulating snowfall is possible on the backside of the mean surface low over the Front Range. A corresponding heavy snow risk was considered in the updated outlook, however there is a lack of ensemble support for amounts exceeding hazard criteria for the higher elevations. Due to antecedent dryness combined with unseasonably warm temperatures and below-normal precipitation favored over the southeastern CONUS during week-1, a Rapid Onset Drought (ROD) risk remains issued for parts of Mississippi, Alabama, Georgia, and South Carolina. However, this risk will be closely monitored for removal in upcoming outlooks should models come into a better consensus with the heavy precipitation risk shifting into these highlighted areas. With above-normal snowpack and above-normal precipitation being registered for much of the Great Lakes, seasonal spring melt has led to saturated soils as well as widespread river flooding, thus any additional water in the river systems will not be easily accommodated. Much of the Great Lakes remains favored for above-normal precipitation during the next two weeks, which could result in accelerated snow melt exacerbating the flooding potential. A flooding possible hazard is posted for parts of the Great Lakes region and Upper and Middle Mississippi Valley, where the confluence of these parameters is greatest. However, the threat of flooding is not limited to these areas alone, as lingering snow remains on the ground over portions of the High Plains as well. No hazard is issued for the Red River of the North or other watercourses in the region, although river rises are likely as snow melts and localized flooding may occur. The favored persistence of cyclonic flow aloft across much of the western CONUS and surface low development in the Great Plains supports an increased risk of periods of elevated winds during week-2. A broad slight area of high winds remains issued for the higher elevations of the interior West eastward to the Mississippi Valley (Apr 22-25) where uncalibrated tools show increased chances for wind gusts exceeding 34kts (~40mph) through the middle of the week-2. Given the extremely dry winter experienced over the West, any such winds realized may present a potential wildfire hazard. No hazards are issued over Alaska, but flooding can occur this time of year with little or no notice during river ice breakup season. The colder temperatures in the Week-2 Outlook increase the chances of delayed river breakup in Alaska and increase the chances of ice jam flooding. Check the Alaska Pacific River Forecast Center (https://www.weather.gov/aprfc/breakupMap) for the latest conditions or advisories. FORECASTER: Nick Novella $$