318 FXUS21 KWNC 061849 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT April 06 2026 SYNOPSIS: Model guidance favors surface low pressure development over the Great Plains and active weather late in week-1 and extending into early week-2, increasing the potential for heavy precipitation and high winds across portions of the Great Plains, Great Lakes, and the Mississippi and Ohio Valleys. HAZARDS Slight risk of heavy precipitation for portions of the Southern and Central Plains, the Mississippi and Ohio Valleys, and Great Lakes, Tue-Wed, Apr 14-15. Slight risk of high winds for portions of the Southern and Central Plains, the Mississippi, Tennessee, and Ohio Valleys, and Great Lakes, Tue-Wed, Apr 14-15. DETAILED SUMMARY FOR THURSDAY APRIL 09 - MONDAY APRIL 13: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR TUESDAY APRIL 14 - MONDAY APRIL 20: Model solutions from the 0z ECENS and GEFS continue to favor a round of vigorous lee cyclogenesis over the Central Plains late in week-1, and depict heavy precipitation developing ahead of a surface low, initially affecting the Great Plains and moving into the Mississippi Valley by the outset of week-2. Uncalibrated probabilities from the ECENS indicate a broad area centered on the Middle Mississippi with at least a 20% chance of 3-day precipitation accumulation exceeding 1 inch, and while the GEFS is less bullish, it also exceeds the above threshold for portions of the Middle Mississippi and Ohio Valleys. The Probabilistic Extremes Tools (PETs) show a similar picture, with a bullish ECENS broad-brushing at least a 20% chance of 3-day precipitation exceeding the 85th climatological percentile. Given all this, a slight risk of heavy precipitation is posted for Tue-Wed, Apr 14-15 for portions of the Southern and Central Plains, the Mississippi and Ohio Valleys, and Great Lakes. Model solutions continue to depict tight pressure gradients and ensemble mean wind speeds exceeding 20mph ahead of this low pressure system early in week-2, after which the low pressure becomes more diffuse and gradients relax. A slight risk of high winds is posted for much of the Southern and Central Plains, the Mississippi, Tennessee, and Ohio Valleys, and Great Lakes for Tue-Wed, Apr 14-15, during which the wind signal and model agreement is strongest. Although the potential for heavy precipitation remains early in week-2, the potential for long-term flooding is diminished due to the expected fast movement of this system, therefore the flooding possible hazard over the Middle Mississippi Valley has been removed. However, the threat of localized stream and flash flooding remains, and caution should always be exercised with floodwaters. Abundant snow accumulation from the winter remains over portions of the Dakotas and the Upper Peninsula of Michigan, and predicted above-normal temperatures for much of the Lower 48 during week-2, melt-off of this snowpack may rise river levels in the watersheds of the Upper Mississippi and the Red River of the North. No hazard is issued at this time but the situation will be closely monitored in the coming days. No hazards are issued over Alaska, but flooding can occur this time of year with little or no notice during river ice breakup season. Check with the Alaska Pacific River Forecast Center for the latest conditions or advisories. Over Hawaii, persistent Kona low activity has led to heavy rainfall and flooding throughout the state. Ensembles do not show much change in the mid-level pattern with troughing favored to persist over the Central Pacific. PETs continue to indicate elevated chances for 3-day amounts exceeding the 85th percentile, with 3-day total accumulations exceeding an inch for some locations early in week-2, after which the signal diminishes somewhat. The continuation of above-normal and potentially heavy precipitation is likely to worsen already saturated ground conditions and may trigger additional localized flooding in the state. FORECASTER: Danny Barandiaran $$