The Storm Prediction Center has flagged a 2–4% tornado probability near Big Sur as a storm system pushes rain and severe thunderstorms toward the Central Coast on Wednesday, Oct. 21.

Rain was expected to arrive before midday, with South Monterey County favored for the heaviest downpours, KSBW reporter Kyle Bergerson reported. The Weather Prediction Center (WPC) highlighted the southern Central Coast for a marginal risk of excessive rainfall, meaning locally heavy rain could lead to flooding in vulnerable areas.

The bigger threat sits along the Big Sur coastline Wednesday afternoon into early Thursday, Oct. 22. Scattered severe thunderstorms could produce strong, erratic winds, waterspouts or brief tornadoes near the coast. Any tornado would likely be weak and short-lived, the San Francisco Chronicle reported, but the National Weather Service (NWS) warned of possible wind gusts up to 60 mph.

The NWS placed the coast from Monterey to Orange County at a marginal (level 1 of 5) risk of severe weather Wednesday, according to the Chronicle. Forecasters expect 1 to 1.5 inches of rain near Big Sur and in the Santa Lucia Range.

Burn scars raise debris-flow danger

Heavy bursts of rain could cause the most problems near the Timber and Plaskett fire burn scars on the Big Sur coast. The two fires burned more than 55,000 acres combined this summer, according to Monterey County Now. Forecasters at the NWS Bay Area office said there are "definitely concerns for debris flows," the Chronicle reported.

Just a quarter-inch of rain in 15 minutes could be enough to trigger a slurry of rock, mud and debris across Highway 1, according to the U.S. Geological Survey, the Chronicle reported.

Monterey County officials have also warned that burn scars put Highway 1 and other critical infrastructure at risk, the King City Rustler reported. Three flood-monitoring sites were damaged by the fires and are slated for repairs.

County declared emergency, approved $669,000

The Monterey County Board of Supervisors approved an emergency proclamation Oct. 13 and allocated about $669,000 for emergency readiness, flood-warning system repairs and Carmel River Lagoon sandbar management, the Rustler reported. The funding includes $297,104 to replenish the Emergency Operations Center budget, $107,000 for the county's ALERT Flood Warning System and $265,000 for lagoon sandbar work.

Kelsey Scanlon, the county's director of emergency management, said the county has used lessons from damaging storms in 2023 to improve its response, according to the Rustler.

What residents should do

Never drive through floodwater.

KSBW reported that residents should have multiple ways to receive weather alerts and avoid flooded roads. Anyone living downslope of the Timber or Plaskett fire burn scars should be prepared for possible debris flows.

The county is hosting virtual winter storm preparedness meetings at noon and 5:30 p.m. Wednesday, Oct. 21, streamed on the county's YouTube and Facebook pages. Residents can also visit the county's Storm Resources Center for safety checklists, sandbag locations and evacuation information, or sign up for alerts at AlertMontereyCounty.org.

The severe weather threat is expected to diminish by Thursday morning. Drier conditions should return by Friday as high pressure builds, with warmer weather expected into the weekend.