772 FOUS30 KWBC 051547 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 1147 AM EDT Sun Apr 5 2026 Day 1 Valid 16Z Sun Apr 05 2026 - 12Z Mon Apr 06 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER A PORTION OF SOUTH TEXAS... 16Z update... The latest observations continue to show convection across South Texas this morning although coverage and intensity have been decreasing from the west. Hires guidance is depicting hourly rainfall rates of at least 0.50"/hr persisting at least into the mid afternoon hours, especially along the coast and points inland. The Marginal Risk was trimmed across the western/northern boundary to account for observations and model trends. Campbell Previous discussion... Surface analysis overnight showed a surface cold front having made its way across much of Texas leading up to the start of the Day 1 period. Consequently, much of the deepest moisture and best instability needed for intense downpours will have already been ushered out to sea. The HREF and RRFS both lingered the potential for 1 inch per hour rainfall across the southern-most tip of Texas where post-frontal winds had enough of on-shore flow component into the mid- or late-morning. Given the coverage of impervious surfaces due to urbanization that would result in run-off...opted to maintain the Marginal risk area after continuing to shrink the areal coverage from the previous issuance. Bann Day 2 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 Day 3 Valid 12Z Tue Apr 07 2026 - 12Z Wed Apr 08 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF THE EAST COAST OF THE FLORIDA PENINSULA... A cold front will be passing over Florida and provide a focus for above average moisture there and possibly into Gulf Coastal areas. The strongest signals from the 05/00Z numerical guidance was for the heaviest rainfall to be off-shore on Tuesday. Even so...post- frontal on-shore flow has could allow for some showers and thunderstorms to come on-shore with localized downpours. Bann 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