361 FXUS21 KWNC 261807 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT March 26 2026 SYNOPSIS: A pattern change is forecast next week as mid-level low pressure centered over the interior West progresses eastward. This increases the chances for heavy precipitation and high winds over a large part of the contiguous U.S. (CONUS) from parts of the Far West to the Appalachians. At least one surface low pressure system and frontal complex is likely to develop across the High Plains and move northeastward, bringing associated high wind, blowing dust, and wildfire risks to a large part of the central and western CONUS. These features also increase chances for heavy precipitation from the central Plains through the interior East, with a moderate risk posted over parts of the Mississippi and Ohio Valleys and the adjacent Great Lakes early in the period, reflecting the best model agreement. Additional heavy rains may fall later in the week as another mid-level trough forms over the interior West, so the slight risk of heavy precipitation is maintained throughout week-2. HAZARDS Moderate risk of high winds for portions of the Southwest, southern and central High Plains, south-central Great Plains, and adjacent Mississippi Valley, Fri-Sat, Apr 3-4. Slight risk of high winds for much of the western and central CONUS and the Great Lakes Region, Fri-Sun, Apr 3-5. Moderate risk of heavy precipitation from portions of the Middle and Lower Mississippi Valley through the Lower Ohio Valley and adjacent Great Lakes Region, Fri-Sun, Apr 3-5. Slight risk of heavy precipitation from much of the central Great Plains to the Appalachians and central Gulf Coast, Fri-Thu, Apr 3-9. DETAILED SUMMARY FOR SUNDAY MARCH 29 - THURSDAY APRIL 02: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR FRIDAY APRIL 03 - THURSDAY APRIL 09: At the start of week-2, the Canadian ensemble (CMCE) and European ensemble (ECENS) means depict a fairly amplified 500-hPa trough centered over the interior West. The GEFS mean shows a more amorphous pattern with a weaker mid-level trough farther north, but this is inconsistent with most guidance and with yesterday's tools, and is not the favored solution in this forecast. The ECENS and CMCE mean solutions depict 500-hPa height anomalies 60-120 meters below normal over a large part of the Rockies and Intermountain West as week-2 starts (Apr 3). During the first half of the period, this shortwave is expected to progress eastward and weaken as it heads toward a persistent mid-level ridge over or near the eastern CONUS. In its wake, most models show a mid-level trough redeveloping over the western CONUS. There is significant uncertainty regarding the timing and strength of this second feature, but most guidance depicts a weaker system. Following unseasonably warm weather in March, this longwave pattern change will usher sharply colder temperatures into the West, in association with higher surface pressures and potentially high winds. Farther east, the mid-level trough is expected to abet lee-side cyclogenesis over the High Plains, with an associated warm front to the east and a trailing cold front to the south. Deterministic models and their ensemble members are converging on surface low development either over eastern Colorado or Wyoming, although some uncertainty remains. Given good model agreement early week-2 on this evolving surface and 500-hPa pattern, along with springtime climatology, a moderate risk of high winds for April 3-4 is posted across parts of the Southwest, central and southern sections of the Rockies and High Plains, the central Great Plains, and the adjacent Mississippi Valley. A larger slight risk area covers much of the western and central CONUS and the Great Lakes Region through April 5 due to less robust model support for high winds, and inconsistent model solutions beyond the middle of week-2. In addition, antecedent conditions are likely to be unseasonably warm during the final week of March, which will continue the ongoing trend of declining surface moisture across the central and western CONUS. The combination of the anticipated gusty winds with dry surface flora growth will likely result in high wildfire danger through much of this region at least into the middle of week-2, particularly in areas not affected by heavy rainfall. The expected mid-level trough in the West may create enough instability to induce dry thunderstorms over the parts of the West, which could serve as triggers for fire development. Farther east, the Morrill wildfire in southwestern Nebraska recently became the largest in state history, consuming more than 600,000 acres. The year-to-date total over the western half of the CONUS exceeds 920,000 acres, compared to the 10-year average of about 650,000 acres across the entire CONUS. The surface low over the Great Plains is expected to track northeastward through the Great Lakes as the mid-level trough pushes northeastward. A leading warm front is expected to form and lift northward ahead of the surface low pressure while a trailing cold front is expected to push eastward across the Plains and into the interior eastern CONUS early in the period, potentially accompanied by heavy rainfall. Today's ECENS and CMCE means are in better agreement early week-2, with both forecasting heavy rainfall focused on similar areas with similar timing. This supports a moderate risk of heavy precipitation which is posted for the first three days of week-2 (Apr 3-5) from portions of the Lower and Middle Mississippi Valley northeastward through the Tennessee and Lower Ohio Valleys, and the adjacent lower Great Lakes Region. Both the ECENS and CMCE means forecast between 1 and 2.5 inches of rain in this area for Apr 3-5. Thereafter, the evolution of surface conditions over this region is unclear due to increasing model spread, but it seems likely that a weaker mid-level trough will form across the western CONUS as a potent mid-level ridge pushes into the northeastern North Pacific. A preponderance of the models indicate at least the potential for surface pressures over the Great Plains to begin dropping again, resulting in a slow-moving frontal complex which would serve as a focus for the additional heavy precipitation. The ECENS and CMCE means both drop 2 to locally over 4 inches of rain on the moderate risk area for week-2 as a whole, indicating that additional rainfall is likely later in the period. In any case, high surface pressure centered off the Southeast coast is expected to keep a persistent southerly flow of moist air from the Gulf into portions of the central and interior eastern CONUS, making abundant moisture available for any mechanism that could trigger shower and thunderstorm activity. This set-up raises the possibility of several rounds of heavy precipitation to continue impacting at least parts of this large region throughout week-2, which supports posting a slight risk of heavy rain that continues throughout the period. There is large model spread, and therefore significant uncertainty, regarding the timing, location, and intensity of any precipitation that does develop later week-2, which precludes posting any moderate risks later week-2. The CMCE and ECENS means agree that weak 500-hPa troughing initially over Mainland Alaska will diminish with time with increasing 500-hPa heights and potentially some mid-level ridging. This evolution does not support hazardous weather across the state during week-2, although mean temperatures are expected to be below normal in southeastern Alaska, gradually moderating with time. In addition, even though above-normal precipitation is slightly favored across most of the state, excessive amounts seem unlikely. Multiple Kona Lows brought flooding rainfall to Hawaii during mid-March. The outlook shows somewhat increased chances of above-normal precipitation through at least part of the first week of April, but this is in association with a wetter-than-normal trade wind regime as opposed to additional excessive amounts, which can be triggered by Kona Lows. FORECASTER: Rich Tinker $$