Light rain fell on parts of the Southland Wednesday, beginning two days of anticipated precipitation which is expected to douse the region but will likely be too sparse to trigger significant mud or debris flows in recent burn areas.
Rain began falling in some coastal areas during the morning rush hour, with the system then spreading slowly inland. “Steady rain” is expected to linger in the evening hours in much of Los Angeles County, but overall rain totals are expected to be relatively low, according to the National Weather Service.
Wednesday’s system “will not be that much of a rainmaker, producing only a third to two-thirds of an inch of rain,” according to the NWS. “Rainfall rates will be under a quarter-inch per hour, so there is no threat to the recent burn areas.
“Max temps will tumble 8 to 12 degrees today and will end up mostly in the mid to upper 50s across the coasts and valleys.”
A “lull” in the rain is expected overnight, with only some scattered showers expected, forecasters said.
But more showers are anticipated on Thursday, with the strongest rain anticipated in the afternoon and evening hours, when there will also be a slight chance of thunderstorms.
“Even though less rain will fall during the day — generally a tenth to a quarter-inch, locally a half-inch — the local rainfall rates could approach a half-inch per hour under thunderstorms or convective bursts,” forecasters said.
Snow levels will drop to about 4,000 feet Wednesday night, and down to around 3,500 feet Thursday. As much as 2 inches of snow is possible in the Grapevine area on Thursday, “but there is a greater chance of just snow in the air with less than inch accumulations,” according to the NWS.
Gustier winds are also expected Thursday, with most areas seeing temperatures in the mid-50s.
Rainy conditions will taper off by Thursday night, forecasters said.
“Dry and warmer weather expected Friday through the weekend, then another series of storm systems will bring more rain and mountain snow to the region next week,” according to the NWS.
Los Angeles County public works crews were mobilized due to the rainy forecast to ensure flood-control systems were prepared. County officials warned that some streets could be flooded or blocked by debris, particularly in recent burn zones.
The city of Sierra Madre issued evacuation warnings that will be in effect until 6 a.m. Friday for “high-risk areas.” Residents were urged to visit project.genasys.com/search to review evacuation warnings in their neighborhoods.
Other areas in the Eaton Fire burn area were also placed under evacuation warnings Wednesday, with the county sheriff’s department warning of a “low risk” of debris flows and flash flooding.
“Anticipate minor to moderate flooding and mudflow/sediment deposition,” sheriff’s officials said in a statement.