759 FXUS21 KWNC 161918 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT April 16 2026 SYNOPSIS: Mid-level low pressure forecast over the western contiguous U.S. (CONUS) and associated lee cyclogenesis supports the increased potential for heavy precipitation across many interior portions of the eastern half of the CONUS, episodes of high winds in the Lee of the Rockies and Gulf Coast, and high elevation heavy snow in the Rockies. The favored eastward expansion of the heavy precipitation risk is expected to provide relief for many moisture starved portions of the Southeast. Anticipated surface low pressure near or along the East Coast and its trailing front may increase chances for high winds for parts of the Mid-Atlantic Coast. Over the upper Midwest, flooding is possible associated with persistent near to above-normal precipitation accelerating spring snowmelt over the next two weeks. HAZARDS Moderate risk of heavy precipitation for portions of eastern Texas, Middle and Lower, Ohio, and Tennessee Valleys, Southern Appalachians, and Southeastern U.S., Fri-Sat, Apr 24-25. Slight risk of heavy precipitation for portions of the eastern Great Plains, Great Lakes region, Mississippi, Tennessee, and Ohio Valleys, Appalachians, and Southeast, Fri-Sun, Apr 24-26. Slight risk of heavy snow for the Northern and Central Rockies, Fri-Sun, Apr 24-26. Moderate risk of high winds for portions of the Great Plains and Southern Rockies, Fri-Sat, Apr 24-25. Slight risk of high winds for parts of the Great Plains, Central and Southern Rockies, Southwest, and Gulf Coast, Fri-Sat, Apr 24-25. Slight risk of high winds for portions of the Mid-Atlantic and Southeast coast, Fri-Sun, Apr 24-26. Possible flooding for parts of the Great Lakes region and Upper and Middle Mississippi Valley. DETAILED SUMMARY FOR SUNDAY APRIL 19 - THURSDAY APRIL 23: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR FRIDAY APRIL 24 - THURSDAY APRIL 30: During week-2, dynamical models continue to feature a transient 500-hPa height pattern. Anomalous mid-level troughing favored across the southwestern CONUS at the beginning of week-2 is anticipated to retrograde and gradually weaken over the period. Meanwhile as surface low pressure centered over Nova Scotia is predicted to move offshore at the start of the period, mid-level troughing is predicted to develop over the north-central CONUS and progress eastward across the eastern CONUS potentially lingering across the region towards the end of week-2. Multiple model ensemble guidance continues to indicate the development of an amplified ridge centered near the Davis Strait consistent with a transition towards a negative North Atlantic Oscillation (-NAO) circulation. This pattern shift may be in response to a high amplitude Madden-Julian Oscillation (MJO) unfolding in the tropical western Pacific. Negative height departures are anticipated to overspread much of the eastern CONUS favoring cooler temperatures for much of the central and northeastern CONUS during week-2. There continues to be good model agreement indicating increased potential of enhanced precipitation across much of the interior eastern CONUS ahead of the aforementioned mid-level trough over the West at the beginning of week-2. The moderate risk area has been expanded eastward and southward, to include portions of eastern Texas, Middle and Lower Mississippi, Ohio, and Tennessee Valleys, Southern Appalachians, and Southeastern U.S., Apr 24-25. The highlighted risk area is primarily based on the notably increased probabilities in the uncalibrated GEFS of 8 to 10 day totals exceeding one inch (the bulk of the heaviest precipitation is anticipated to occur from the end of week-1 into the first two days of week-2). The ECENS and GEFS Probabilistic Extremes Tool (PET) shows at least a 30% chance of 3-day accumulations exceeding one inch with the ECENS indicating at least a 40% across the Lower Mississippi Valley. A broader area of slight risk is designated across the eastern Great Plains, Great Lakes region, Mississippi, Tennessee, and Ohio Valleys, Appalachians, and Southeast, Apr 24-26. The northern periphery of this risk area across the Great Lakes and adjacent areas of the Ohio Valley and Middle Mississippi Valley are anticipated to have slightly lower accumulated precipitation totals (e.g. 3-day totals greater than 0.75 inches), but continue to be highlighted due to potential exacerbation of possible flood across parts of the Great Lakes region and Upper and Middle Mississippi Valley. Across the southeast, possibly enhanced rainfall would be beneficial for areas that have been dry. Surface low pressure across portions of the Rockies continues the slight risk of heavy snow for the Northern and Central Rockies, Apr 24-26. The GEFS Snow Water Equivalent (PET) indicates a 20% chance of 3-day accumulations exceeding the 85th percentile and half an inch (liquid equivalent), with uncalibrated ensembles indicating a greater than 40% (20%) chance for the Central (Northern) Rockies. Lee cyclogenesis across the Great Plains ahead of the mid-level low across the West shifting eastward supports increased likelihood of episodic high winds at the beginning of week-2. Multiple models indicate a deeper low centered over the Central and Southern Plains compared to yesterday. This would increase the wind speeds across the central CONUS. Due to good model consistency and increasing signals for high winds a moderate risk is designated for portions of the Great Plains and Southern Rockies, Apr 24-25. The ECENS ensemble shows at least a 40% chance of wind gusts exceeding 34 mph in this risk area. A broader area of slight risk is highlighted for parts of the Great Plains for the same period. Additionally, surface low pressure near or along the East Coast and its trailing front may increase chances for high winds for parts of the Mid-Atlantic and Southeast Coast early in the period. Gusty winds could increase wildfire risk especially across the Southern Plains where soils are dry and there are currently active wildfires. Surface low pressure shifting from the western to central CONUS combined with surface low formation off the Mid-Atlantic coast may also support high winds extending to the Gulf Coast. Slight risks are designated for portions of the Great Plains and Gulf Coast, Apr 24-26, and portions of the Mid-Atlantic coast, Apr 25-26. 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 near to 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. Surface low formation in the Gulf of Alaska combined with anomalous cold temperatures and above normal precipitation predicted for Alaska, could support anomalously heavy late season snow for southern Mainland Alaska. No associated snow hazards are posted at this time with the expectation for totals to not reach hazardous criteria. Despite no associated flood hazards, 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: Melissa Ou $$