207 FXUS21 KWNC 121746 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT April 12 2026 SYNOPSIS: Mid-level low pressure over the western contiguous U.S. (CONUS) early in the period is forecast to progress east with time. This increases chances for high winds over much of West and Plains. By the middle of the period, a frontal system is favored to develop over the Mississippi Valley and into the Ohio and Tennessee Valleys and may bring heavy precipitation. Southeast of this system, dry air is favored to remain entrenched, increasing risks for rapid onset drought and intensification of drought over the southeastern U.S. HAZARDS Slight risk of heavy precipitation for portions of the Southern Plains, Middle and Lower Mississippi, Tennessee, and Ohio Valleys, Wed-Fri, Apr 22-24. Slight risk of high winds for much of the Great Plains, Rocky Mountains, Great Basin, Desert Southwest, and southern California, Mon-Thu, Apr 20-23. Possible flooding for much of Wisconsin and Michigan. Rapid Onset Drought risk across parts of Mississippi, Alabama, Georgia, and South Carolina. DETAILED SUMMARY FOR WEDNESDAY APRIL 15 - SUNDAY APRIL 19: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR MONDAY APRIL 20 - SUNDAY APRIL 26: A progressive spring pattern is forecast for week-2 across the CONUS. Mid-level troughing over the West with ridging over the East is favored early in the period. Over time, the trough progresses east and displaces the positive 500-hPa height anomalies over the East. By the end of the period, ensemble model guidance is quite uncertain lending to a zonal forecast in the ensemble means. Mid-level troughing is anticipated to track across the western CONUS at the beginning of week-2, supporting a series of surface lows developing across the region. These lows combined with adjacent surface high pressure across the eastern CONUS results in a tight pressure gradient across the central CONUS. This supports the continued slight risk for high winds over much of the Great Plains, Rocky Mountains, Great Basin, Desert Southwest, and southern California Apr 20-23. Given the extremely dry winter experienced over the West such winds present a potential wildfire hazard. As the trough moves into the Plains, surface low pressure may develop in the lee of the Rockies. An associated frontal system will then move into the Mississippi, Ohio and Tennessee Valleys by the middle of week-2. There remains a great deal of spread in the ensemble guidance but the Probabilistic Extremes Tools indicate at least a 20% chances of three day precipitation amounts exceeding the 85th climatological percentile and 1 inch across a pretty broad region. Uncalibrated ensemble guidance is also supportive of this broad shape with some fairly slight differences between the physical guidance and machine learning tools. Therefore, a slight risk of heavy precipitation is posted for portions of the Southern Plains, Middle and Lower Mississippi, Tennessee, and Ohio Valleys, Apr 22-24. Anomalous warmth is still favored for much of the CONUS during week-2, with the greatest likelihood across the southeastern quadrant of the CONUS. This warmth combined with antecedent and anticipated dry conditions increases the likelihood of Rapid Onset Drought (ROD) across parts of the region. A risk of ROD is posted for parts of Mississippi, Alabama, Georgia, and South Carolina. Additionally these conditions may also be conducive to enhanced wildfire risk across the southeastern CONUS, where there are currently active fires and the National Interagency Fire Center shows a moderate risk of wildfires across this region at the end of week-1. An abundant snowpack over portions of northern Michigan is beginning to melt. Additionally, over the last week the Great Lakes region has reported precipitation accumulations exceeding 2 inches in most locations. This has saturated soils and already lead to widespread river flooding, thus any additional water in the river systems will not be easily accommodated. Much of the Great Lakes is favored for above-normal precipitation, with southern portions of the region favored to have near to above-normal temperatures excluding the Upper Peninsula, which could result in accelerating snow melt and exacerbating the flooding potential. A flooding possible hazard is posted for most of Michigan and Wisconsin, 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. 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 with the Alaska Pacific River Forecast Center (https://www.weather.gov/aprfc/breakupMap) for the latest conditions or advisories. FORECASTER: Ryan Bolt $$