619 FOUS30 KWBC 180016 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 716 PM EST Tue Feb 17 2026 Day 1 Valid 01Z Wed Feb 18 2026 - 12Z Wed Feb 18 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF CENTRAL AND SOUTHERN CALIFORNIA... 18/01Z update: Leading shortwave within the larger scale trough has continued to dig into portions of central California during the afternoon...focusing low level WAA along/ahead of a cold front. MRMS has depicted hourly rainfall rates generally 0.2 inches or lower although isolated spots have briefly seen rates approach 0.5 inches. The southward progression will continue to limit overall totals to below 2.5" even within the terrain (or below freezing level along the lower slopes of the Sierra Nevada), but as noted below the antecedent upper soils are fairly saturated and that slightly above average run-off remains expected into the middle of the night. Even so...any flooding would likely be minor or localized and mostly affect urban settings and/or recent burn scars, initially through central CA. Through evening, there is some hint of some increased southerly flow in the surface to boundary layer intersecting the pre-frontal plume and IVT values may reach 500+ kg/m/s, however, the intersection with terrain will be a bit more oblique than it was 24 hours ago...maintaining or slightly reducing the deep layer moisture convergence that will be driving the rainfall rates (still generally about .3-.5"/hr) mainly through 18/06Z. Removed the northern portion of the Marginal Risk area where the plume of deepest moisture and greatest coverage of rainfall has pushed south. Given the steep mid-level lapse rates near the core of the mid/upper level feature...there could still be isolated moderate rainfall rates from passing showers but not with enough intensity or duration to support a Marginal Risk. There were no substantial changes to the Marginal Risk area farther south. Gallina/Bann ~~~~Prior Discussion~~~~ 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