Quantitative Precipitation Forecast
Issued by NWS
Issued by NWS
380 FOUS30 KWBC 300800 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 300 AM EST Sun Nov 30 2025 Day 1 Valid 12Z Sun Nov 30 2025 - 12Z Mon Dec 01 2025 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Wegman Day 2 Valid 12Z Mon Dec 01 2025 - 12Z Tue Dec 02 2025 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE GULF COAST AND DEEP SOUTH... A fast-moving positively tilted shortwave trough will move east in parallel with a strong cold front that will sweep across the South, drawing abundant Gulf moisture for December north and east along the frontal interface. The enhanced lift associated with both the shortwave trough and attendant jet streak will favor cyclogenesis, especially Monday night as the low forms across far southern Georgia and coastal South Carolina. While the cold front will push the Gulf moisture with embedded thunderstorms along to the east, by the time the low forms along the front, it will have generally stalled out, with little southward progress. This should act to keep the pattern quite progressive, even if areas will still see heavy rain from thunderstorms. Further, the soil moisture levels across much of the South are below to well below average. This should support the soils largely soaking up the mostly stratiform (albeit with embedded convection) rain. There were few changes made to the Marginal Risk area, as the area of greatest concern for isolated instances of flash flooding are the urban centers from Houston east through New Orleans, Montgomery, and Atlanta. Wegman Day 3 Valid 12Z Tue Dec 02 2025 - 12Z Wed Dec 03 2025 The probability of rainfall exceeding flash flood guidance is less than 5 percent. The inherited Marginal Risk along much of the Eastern Seaboard from South Carolina north through Massachusetts was dropped, resulting in another blank ERO map with this update. The progressive nature of the low as it moves up the coast, despite somewhat rapid deepening, has resulted in an eastward shift of the heaviest precipitation more off the coast. For those areas not impacted by wintry weather in the interior Northeast/Appalachians, the rainfall along the coastal plain will be almost entirely stratiform, with any convection confined perhaps to the eastern Carolinas. Even in the Carolinas any convection will be fast-moving and embedded within a much larger stratiform rain shield. Thus, the combination of lower forecast rainfall amounts and the stratiform nature of the rain should result in a rather long-duration light rain along the coast in most areas. The heaviest rains Tuesday could even remain east of the I-95 corridor, and thus largely missing the bigger metros. Just like in the Deep South, soils along the Eastern Seaboard are also drier to much drier than normal for this time of year. Thus, any rainfall will be largely beneficial in these areas as well. Wegman Day 1 threat area: https://www.wpc.ncep.noaa.gov/qpf/94epoints.txt Day 2 threat area: https://www.wpc.ncep.noaa.gov/qpf/98epoints.txt Day 3 threat area: https://www.wpc.ncep.noaa.gov/qpf/99epoints.txt