033 FXUS21 KWNC 051734 PMDTHR US Hazards Outlook NWS Climate Prediction Center College Park MD 300 PM EDT April 05 2026 SYNOPSIS: Mid-level low (high) pressure across the western (eastern) contiguous U.S. (CONUS) increases chances for heavy precipitation across most of the Plains, the Mississippi and Tennessee Valleys, much of the Ohio Valley, and the Great Lakes Region early week-2. The heaviest rain appears most likely across central and northeastern Texas, eastern Oklahoma, and the adjacent Lower Mississippi Valley, where there is a risk of flooding. Isolated, brief high wind gusts are possible along and north of a cold front from the central CONUS through the Great Lakes and Northeast. An upstream mid-level trough may continue the spate of heavy precipitation in Hawaii during the first half of week-2. HAZARDS Moderate risk of heavy precipitation from the Southern Plains northeastward across much of the Mississippi Valley, adjacent parts of the Ohio and Tennessee Valleys, and the Great Lakes, Mon, Apr 13. Slight risk of heavy precipitation for much of the Plains, the Mississippi Valley, much of the Ohio Valley, the Tennessee Valley, and the Great Lakes, Mon-Tue, Apr 13-14. Flooding possible over parts of the southeastern Great Plains and adjacent Lower Mississippi Valley. DETAILED SUMMARY FOR WEDNESDAY APRIL 08 - SUNDAY APRIL 12: https://www.wpc.ncep.noaa.gov/threats/threats.php FOR MONDAY APRIL 13 - SUNDAY APRIL 19: Models are in good agreement establishing mid-level ridging over the eastern CONUS and upstream troughing across the interior West during week-1. This trough lifts northeastward early week-2, and the predicted strength of the trough is similar to yesterday, slowly weakening as it moves east. This pattern elevates the chances for heavy precipitation across a large part of the central and interior eastern CONUS. Isolated high wind gusts are possible along and north of a cold front advancing southeastward ahead of Canadian high pressure, from the central CONUS through much of the Great Lakes and Northeast, but model support for more widespread high winds is low, and no wind threat is posted. Models begin to diverge around the middle of week-2, and by Thu, Apr 16, the Canadian ensemble (CMCE) mean keeps a mid-level ridge over the eastern CONUS while the GEFS mean shows a mid-level trough extending southward out of eastern Canada into the same region. The European ensemble (ECENS) mean splits the difference with a relatively amorphous 500-hPa flow. Some guidance shows the risk of heavy rainfall increasing again later week-2 over portions of the central and eastern CONUS, but the model divergence leads to a highly uncertain forecast after the middle of week-2. By the start of week-2, increased low-level Gulf moisture is forecast to overspread most areas between the Rockies and the Appalachians as surface high pressure centered over the western Atlantic extends into the southeastern CONUS. Farther west, the mid-level trough is expected to induce lower surface pressure over the central CONUS, setting the stage for a surface low pressure center and associated frontal complex to pass through the region. The influx of low-level moisture into this system increases the odds for heavy precipitation over a large part of the central and interior eastern CONUS early week-2. Guidance has consistently forecast the heaviest amounts over northeastern Texas, eastern Oklahoma, and the adjacent Mississippi Valley late week-1 into early week-2, increasing the risk of flooding there. There is somewhat more divergence among the guidance farther north regarding the location, timing, and intensity of heavy precipitation, but most tools generally agree on an increased chance for heavy rain to fall on a swath extending northward from Texas through the Great Lakes Region. These factors support a moderate risk of heavy precipitation for the first day of week-2 (Mon, Apr 13). There is considerably more uncertainty to the west and east of this primary threat area, but the mid-level set-up has the potential to trigger heavy precipitation as far west as the Great Plains and Upper Mississippi Valley, and as far east as the central Gulf Coast, the western Appalachians, and the Great Lakes Region during the first two days of week-2 (Mon-Tue, Apr 13-14). Continuous heavy precipitation throughout this region and time period seems unlikely, but the synoptic situation is favorable for the development of periodic, locally heavy thunderstorms to affect scattered parts of this region. After Tue, Apr 14, the mid-level trough and associated surface features weaken, and models begin to diverge, bringing an end to the enhanced chances for heavy rainfall. Rainfall will be maximized wherever there is a combination of strong low-level moisture influx, a focusing frontal boundary, and surface instability, and this seems most likely from central and northeastern Texas, eastern Oklahoma, and adjacent areas to the north and east. Probabilistic Extremes Tools (PETs) derived from the GEFS, European ensemble (ECENS), and Canadian ensemble (CMCE) are not particularly bullish on the potential for heavy precipitation, with only the ECENS showing any areas with a greater than 40 percent chances for 3-day precipitation totals above the 15th percentile climatological threshold (centered over Texas and adjacent locales). However, amounts of 1-3 inches are depicted by the deterministic European (ECMWF) and European AI-enhanced (ECMWF-AI) models as well as the ECENS and CMCE means across different parts of the slight risk area. Several tools show at least some risk of additional heavy precipitation over portions of the slight risk region later week-2, especially across the southern reaches, but there is too much uncertainty and model disparity to justify posting any additional heavy precipitation risks at this time. The PETs are not indicating much of a high wind threat, and the probabilities for high wind gusts indicated by the ECENS and CMCE are lower than yesterday. In addition, the ECMWF wind gust forecast is weaker than in earlier model runs. As a result, no high wind hazards are posted, although isolated high wind gusts may occur from the central CONUS through the Great Lakes and Northeast, along a weakening frontal boundary ahead of Canadian high pressure. 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. Across Hawaii, Kona Low activity brought heavy rainfall and flooding during mid-March, and strong trade winds have helped keep precipitation totals above normal for the past few weeks. Ensemble guidance shows a mid-level trough to the north of the island chain early week-2, which may trigger additional heavy precipitation. PETs from the CMCE, GEFS, and ECENS show increased chances (20 to 30 percent) for 3-day amounts exceeding the 85th percentile early week-2, with declining chances for heavy precipitation thereafter. Any heavy precipitation during week-2 will be falling on saturated ground, potentially triggering localized flooding. FORECASTER: Rich Tinker $$