463 FOUS30 KWBC 260634 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 234 AM EDT Thu Mar 26 2026 Day 1 Valid 12Z Thu Mar 26 2026 - 12Z Fri Mar 27 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE MIDWEST THROUGH PORTIONS OF THE CENTRAL AND NORTHERN APPALACHIANS... A strong cold front tracking south out of the Great Lakes and Canada will provide the primary forcing for a line consisting of several segments of severe thunderstorms this evening through the overnight period. Working against flash flooding remains the very fast movement of any individual cells of heavy rain, the progressive southward movement of the cold front, average soil moisture (which usually can stand to soak in lots of rain before the rest converts to runoff), and average PWATs (around 1.25 inches) and instability (between 1,000 and 1,500 J/kg of MUCAPE). Working for flash flooding is the several urban areas which locally lower FFGs and have more flood-prone areas, good potential for training storms, and into portions of southwest Pennsylvania, upslope potential against the mountains. Into Illinois, ongoing slow moving showers and storms are locally saturating soils in east-central portions of the state and into western Indiana. Rainfall forecast amounts have increased a bit across Ohio and southwest Pennsylvania. This moves the threat up into the higher- end Marginal risk category (10-15% chance of exceeding Flash Flood Guidance). Thus, any further increases in the rainfall amounts may require a targeted Slight later today anywhere from Illinois to southwest Pennsylvania, generally along I-70. Wegman Day 2 Valid 12Z Fri Mar 27 2026 - 12Z Sat Mar 28 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Wegman Day 3 Valid 12Z Sat Mar 28 2026 - 12Z Sun Mar 29 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. 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