FSUS46 KLOX 201924 QPSLOX Quantitative Precipitation Forecast National Weather Service Los Angeles/Oxnard CA 1223 PM PDT Mon Apr 20 2026 Precipitation forecasts in inches are provided in 3-hour increments until 0500 followed by 6-hour increments until 1700. Thunderstorm chances cover up to 1700 on day 1 only. Light rainfall amounts greater than zero but less than a tenth of an inch are shown as lgt. The discussion covers the period from: Mon Apr 20 2026 through Sun Apr 26 2026. && 17-20 20-23 23-02 02-05 | 05-11 11-17 San Luis Obispo County... LSRC1:Cambria 0.0 lgt 0.2 0.5 | 0.4 0.2 SMRC1:Santa Margarita 0.0 lgt 0.2 0.5 | 0.4 0.2 NIPC1:Lopez Lake 0.0 0.0 lgt lgt | 0.7 0.1 1-Hr Rates: Coasts/Valleys Foothills/Mountains Expected Peak (in/hr): 0.15-0.35 0.20-0.40 Probability 0.50+ in/hr: 25% 30% Probability 1.00+ in/hr: <5% <5% Peak rates expected to occur between: 0300-1200 Chance of Thunderstorms: 20% Isolated rates around 0.75 in/hr possible near thunderstorms. && 17-20 20-23 23-02 02-05 | 05-11 11-17 Santa Barbara County... SIYC1:Santa Maria 0.0 0.0 0.0 lgt | 0.5 lgt SBTC1:Santa Barbara Potrero 0.0 0.0 0.0 0.0 | lgt 0.2 GBRC1:Gibraltar Dam 0.0 0.0 0.0 0.0 | 0.2 0.6 SMCC1:San Marcos Pass 0.0 0.0 0.0 0.0 | 0.4 0.5 SBFC1:Santa Barbara City 0.0 0.0 0.0 0.0 | 0.2 0.4 1-Hr Rates: Coasts/Valleys Foothills/Mountains Expected Peak (in/hr): 0.20-0.40 0.20-0.40 Probability 0.50+ in/hr: 15% 15% Probability 1.00+ in/hr: <5% <5% Peak rates expected to occur between: 0600-1400 Chance of Thunderstorms: 20% Isolated rates around 0.75 in/hr possible near thunderstorms. && 17-20 20-23 23-02 02-05 | 05-11 11-17 Ventura County... FGWC1:Fagan Canyon 0.0 0.0 0.0 0.0 | lgt 0.3 HRCC1:Hopper Canyon 0.0 0.0 0.0 0.0 | lgt 0.2 MTDC1:Matilija Dam 0.0 0.0 0.0 0.0 | lgt 0.6 VTUC1:Ventura City 0.0 0.0 0.0 0.0 | lgt 0.3 MORC1:Moorpark 0.0 0.0 0.0 0.0 | lgt lgt CRXC1:Circle X Ranch 0.0 0.0 0.0 0.0 | lgt 0.2 1-Hr Rates: Coasts/Valleys Foothills/Mountains Expected Peak (in/hr): 0.05-0.15 0.25-0.35 Probability 0.50+ in/hr: <5% 10% Probability 1.00+ in/hr: <5% <5% Peak rates expected to occur between: 1300-1600 Chance of Thunderstorms: 0% && 17-20 20-23 23-02 02-05 | 05-11 11-17 Los Angeles County... WFKC1:West Fork Heliport 0.0 0.0 0.0 0.0 | 0.0 0.1 BDDC1:Big Dalton Dam 0.0 0.0 0.0 0.0 | 0.0 lgt PCDC1:Pacoima Dam 0.0 0.0 0.0 0.0 | 0.0 0.2 FLTC1:La Canada Flintridge 0.0 0.0 0.0 0.0 | 0.0 lgt SAUC1:Saugus 0.0 0.0 0.0 0.0 | 0.0 lgt CQT:Downtown LA 0.0 0.0 0.0 0.0 | 0.0 lgt MLUC1:Malibu Big Rock Mesa 0.0 0.0 0.0 0.0 | 0.0 0.1 1-Hr Rates: Coasts/Valleys Foothills/Mountains Expected Peak (in/hr): 0.05-0.10 0.01-0.10 Probability 0.50+ in/hr: <5% <5% Probability 1.00+ in/hr: <5% <5% Peak rates expected to occur between: 1300-1600 Chance of Thunderstorms: 0% && DISCUSSION: Rain will begin across SLO county late this afternoon/evening, then will spread south and east tonight through Tuesday evening. Rainfall totals across SLO and SBA counties with widespread 0.50" to 1.00" totals and local amounts up to around 1.50" across some foothill areas. For Ventura and LA counties, totals will be 0.33" or less with local amounts up to around 0.75 across the Ventura county mountains. There is a 10-20% chance of thunderstorms Tuesday, mainly across SLO county. Rainfall rates with this system are expected to be around 0.25" or less per hour. However, with any thunderstorm development, rates up to around 0.50" per hour will be possible. No significant hydrologic issues are expected. Another likely weak storm is possible this weekend or early next week. $$