Rainfall rates and timing
Meteorologists expect light to moderate showers for much of Friday; however, the primary flooding danger is forecast from Friday night into Saturday afternoon. Rainfall rates could approach one inch per hour in the most intense cells, particularly over burn scars where vegetation was lost during recent wildfire seasons.
Between Friday and Saturday, projected precipitation totals include:
- 4 to 6 inches in mountain zones of Santa Barbara, Ventura and Los Angeles Counties.
- 2 to 4 inches across many coastal and valley locations, including Los Angeles, Malibu and Santa Barbara.
- Localized amounts above 6 inches where thunderstorms stall or terrain forces additional uplift.
According to the National Weather Service, a moderate risk of excessive rainfall exists for the Los Angeles and Santa Barbara regions from late Friday through early Saturday afternoon. A broader slight risk encompasses most of Southern California, signaling the possibility of scattered flash-flood events outside the burn scars.
Peak hazard window
Forecasters pinpoint the greatest danger period between 2 a.m. and 3 p.m. local time on Saturday. During those hours, saturated soils, steep slopes and high rainfall rates could combine to generate rapid runoff, mudslides and debris flows. The threat intensifies overnight because reduced visibility complicates both evacuation and emergency response.
Even after the heaviest band exits, additional showers are expected each day next week. With ground already saturated, any new rainfall could quickly trigger renewed slope failures or urban flooding.
State and local preparations
Governor Gavin Newsom announced Thursday that state resources have been pre-deployed to Los Angeles, Orange and Ventura counties. Assets include swift-water rescue teams, road-clearing equipment and emergency operations personnel positioned to assist local authorities if debris flows cut off neighborhoods or damage infrastructure.
Imagem: Internet
Public works crews have inspected storm drains, synchronized debris-basin cleanouts and staged heavy machinery near known trouble spots. Transportation officials warned that temporary road closures are likely on mountain passes and low-lying highways should runoff overwhelm drainage systems.
Storm in historical context
Los Angeles typically records about 0.8 inch of rain during the entire month of November. The standing monthly record, set in 1965, is 9.68 inches. The current system could deliver more than a normal month’s rainfall in roughly 24 hours, setting the stage for runoff totals rarely seen this early in the wet season.
Burn scar areas are especially vulnerable in the first several years after a fire because the loss of vegetation and root structures diminishes soil stability. Hydrophobic layers created by intense heat cause water to race downslope rather than infiltrate, rapidly picking up ash, rocks and fallen trees. Debris flows can travel at high speed, damaging homes, blocking roads and inundating drainage channels.
Safety guidance
Officials urged residents in evacuation zones to:
- Monitor local alerts and move vehicles to higher ground before nightfall.
- Avoid driving through water-covered roadways; just six inches of flowing water can sweep away smaller vehicles.
- Stay clear of storm channels, dry washes and canyon mouths where sudden surges may occur.
- Keep emergency supplies, medications and important documents ready for rapid departure.
Outside mandatory zones, residents across Southern California are advised to secure outdoor furniture, clear gutters and review family communication plans in case power or cellular service is disrupted by falling trees or localized flooding.
Outlook beyond the weekend
Forecast models indicate a series of weaker disturbances could reach the coast next week, prolonging unsettled conditions. With soils already at capacity, even modest rainfall could renew flash-flood concerns, particularly in and below burn scars. Authorities plan to reassess evacuation guidance daily as new data become available.
Crédito da imagem: ABC News
