845 FOUS30 KWBC 170829 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 329 AM EST Tue Feb 17 2026 Day 1 Valid 12Z Tue Feb 17 2026 - 12Z Wed Feb 18 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF CENTRAL AND SOUTHERN CALIFORNIA... A mid-level disturbance centered over the Pacific Northwest Coast will shift south and east into California today. At the surface, a cold front will propagate through the Great Basin and arrive in the Intermountain West by Wednesday morning. Scattered showers and thunderstorms are expected to spread south from the north/central California Coast to SoCal this evening. Instability will be modest, between 50-150 J/Kg MUCAPE, between 00z-12z tonight, which coincides with when the mid-level vort max will be directly overhead. Precipitable water values in the 0.5-0.75" range won't be very anomalous (1-2 stndv), however isolated pockets of efficient rain rates around 1" are possible within areas of higher instability and PWATs. Upslope enhancement along the Central California and Transverse ranges could lead to higher totals in those areas. Lower snow levels on the backside of Monday's cold frontal passage will see most of the higher mountain peaks realize higher QPF in the form of snow. Antecedent conditions from Monday's rainfall will make soils and burn scars susceptible to runoff today. Urban areas will continue to be vulnerable. HREF neighborhood probabilities show a strong signal for at least 1 inch within much of the current marginal risk area. Kebede Day 2 Valid 12Z Wed Feb 18 2026 - 12Z Thu Feb 19 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Kebede Day 3 Valid 12Z Thu Feb 19 2026 - 12Z Fri Feb 20 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Kebede 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