793 FXUS21 KWNC 281759 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT April 28 2026 SYNOPSIS: Mid-level low pressure favored over the eastern contiguous U.S. (CONUS) is expected to bring anomalously cold air and gusty winds to the region. There are increased chances for much below normal temperatures with freezing and near freezing conditions possible in some areas, potentially damaging early spring blooms. A series of surface lows and trailing fronts may bring heavy precipitation to parts of the Southern Plains through the lower Mississippi, Tennessee, and Ohio Valleys into the Southeast at the beginning of week-2. High winds are possible over the Central and Southern Plains and Southwest at the start of the period ahead of mid-level low pressure centered across the Four Corners Region. HAZARDS Slight risk of much below normal temperatures for much of the Midwest, Great Lakes region, Northeast, Mid-Atlantic, and Appalachians, Fri-Sun, May 8-10. Slight risk of high winds for much of the eastern U.S., Wed-Sun, May 6-10. Slight risk of heavy precipitation for portions of the Southern Plains, Lower and Middle Mississippi, Ohio, and Tennessee Valleys, Southern Appalachians, and Southeastern U.S., Wed-Fri, May 6-8. Slight risk of high winds for parts of the Central and Southern Plains and Southwest, Wed-Thu, May 6-7. DETAILED SUMMARY FOR FRIDAY MAY 01 - TUESDAY MAY 05: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR WEDNESDAY MAY 06 - TUESDAY MAY 12: Multiple models continue to indicate amplified mid-level troughing over the Midwest shifting to the northeastern CONUS at the beginning of week-2. This feature combined with mid-level ridging south of Greenland is consistent with a negative North Atlantic Oscillation (-NAO) pattern, which dynamically (and historically) supports the advection of anomalous cold air into many parts of the central and eastern CONUS. Compared to yesterday, the GEFS, ECENS, and CMCE ensemble means indicate greater 500 hPa negative height departures across the East from the beginning to middle of the period. The slight risk of much below normal temperatures is expanded eastward due to stronger cold signals and progression eastward of the mid-level trough to include much of the Midwest, Great Lakes region, Northeast, Mid-Atlantic, and Appalachians, May 8-10. The middle of the period is still favored for the greatest chances for this hazard when surface high pressure from central and eastern Canada sinks southward into the eastern U.S. after the passage of a series of surface low pressure and trailing cold fronts which would promote more warm southerly flow. Both the GEFS and ECMWF Probabilistic Extreme Tools (PETs) indicate at least a 20% chance of minimum temperatures falling below the 15th percentile climatologically and 40 degrees F (freezing temperatures across the northern portions). Any residual cold with freezing or near freezing temperatures may threaten vulnerable springtime vegetation, particularly in areas that have experienced early growth due to antecedent warmth during April. The aforementioned series of surface lows predicted to move across the eastern CONUS tied to the troughing aloft may bring episodes of high winds to parts of the East. Therefore a broad area remains highlighted with a slight risk of episodic high winds across the eastern CONUS, May 6-10. PETs show at least a 20% chance of wind speeds exceeding the 85th percentile across the region with wind gusts approaching or exceeding 25 mph. Additionally, models have increased signals for enhanced precipitation across southern portions of the East associated with these lows and fronts compared to yesterday. A slight risk of heavy precipitation is designated for portions of the Southern Plains, Lower and Middle Mississippi, Ohio, and Tennessee Valleys, Southern Appalachians, and Southeastern U.S., May 6-8. The PETs are in good agreement indicating at least a 20% chance of 3-day accumulated precipitation exceeding the 85th percentile and one inch. Thunderstorms are possible across this region and adjacent areas of where this risk is highlighted, which could lead to localized flooding. Multiple model ensemble means indicate stronger mid-level troughing across the Four Corners and southwestern CONUS at the beginning of the period compared to yesterday. This pattern could support surface lows forming in the lee of the Rockies, where combined with adjacent surface high pressure over the central CONUS could support a tight pressure gradient and resultant enhanced wind speeds. Therefore a slight risk of high winds is designated across portions of the Central and Southern Plains and Southwest, May 6-7. Some areas could experience wind gusts nearing or exceeding 40mph. Over Alaska, models continue to favor mid-level troughing over the Bering Strait with ridging over the Mainland. An associated mean surface low centered over the Aleutians is expected to bring potentially strong winds and stormy conditions along the southwestern portions of the state early in week-2 before the pattern aloft deamplifies. Conditions are expected to remain below hazard thresholds, and no corresponding wind or precipitation shapes are posted. Additionally, the typical peak of the river ice breakup season is approaching, and ice jam flooding can occur this time of year with little or no notice as conditions on frozen rivers can change quickly. Please check with the Alaska Pacific River Forecast Center for the latest conditions and advisories. FORECASTER: Melissa Ou $$