FOUS30 KWBC 050100 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 900 PM EDT Sat Apr 4 2026 Day 1 Valid 01Z Sun Apr 05 2026 - 12Z Sun Apr 05 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF THE LOWER MISSISSIPPI VALLEY... ...0100 UTC Update... Based on the latest observational trends (including satellite, radar, and mesoanalysis), we were able to remove the Slight Risk area over eastern TX into the ArkLaTex, while also paring back the western periphery of the Marginal Risk from TX to the Midwest- western OH Valley. Meanwhile, we also removed the Slight Risk across Northeast IN-northern OH-southwest PA, also based on current trends and the latest high-res guidance (including recent HRRR runs and 18Z HREF QPF exceedance probabilities). Per the latest SPC mesoanalysis, MUCAPEs are struggling across this region, generally ranging between 100-500 J/Kg, with the MUCAPE trends actually down over the past several hours. Per the observed KPIT 00Z sounding, there's quite a bit of dry air below 750 mb, which is helping to stabilize the lower layers with the rain falling from the more elevated cloud bases. Hurley Day 2 Valid 12Z Sun Apr 05 2026 - 12Z Mon Apr 06 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF SOUTH TEXAS ON SUNDAY... Steady progression of a cold front from the north will lead to the first 6hrs of the period being the highlight for any flash flooding concerns across Deep South Texas. The trends have been for the front to clear the Rio Grande in the morning, so some lingering heavy rainfall across the four southernmost counties from Zapata to Cameron will be the most susceptible to localized flash flood concerns in the D2. The NAM Nest continues to be the least progressive with the cold front leading to lingering heavy convection up by Jim Hogg to Kleberg counties, so kept the MRGL risk in a similar alignment to the previous forecast to account for the potential. Much of the rainfall will be beneficial, so the primary threat will be within the more urbanized portions of South TX. Rainfall totals between 1-2" will be most common with prob fields indicating a low-end potential for 3-5" in the strongest storms. Kleebauer Day 3 Valid 12Z Mon Apr 06 2026 - 12Z Tue Apr 07 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Bann/Kleebauer 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