While some Southern California neighborhoods got doused with up to an inch and a half of rain throughout the day on Wednesday, lots of folks played peekaboo with the sun, as the latest winter storm made its way down from the Bay Area.
The fairly low key (for us) storm is expected to intensify into the night and peak into early Thursday. We'll see scattered showers throughout the day, but we should be all nice and dry by Friday.
The most concerning hazards are going to be isolated pockets of heavy rainfall, which could result in debris flows, and low elevation snow impacting mountain roads. Potential thunderstorms could also bring hail and lightning.
As for tornadoes?
"There's a non-zero chance of a tornado or waterspouts off shore. This is always a threat for us during winter storms," said Todd Hall, meteorologist with the National Weather Service. "We're sitting at less than a 2% chance of a tornado."
It's raining, it's pouring, the old man is 😴💤! Here is our latest forecast for rainfall timing and intensity. There is a slight chance of thunderstorms Wednesday and Thursday. pic.twitter.com/FYiq07REmD
— NWS Los Angeles (@NWSLosAngeles) March 28, 2023
The concerning, heavy bursts of rain are most likely to occur late Wednesday into early Thursday.
As usually happens during storms with heavy rain, debris flows are of particular concern in recently burned areas. The Los Angeles County Department of Public Works has said that minor-to-moderate flooding should be anticipated in La Tuna Canyon, Agua Dulce, Sunland-Tujunga, and a few other spots.
Consider avoiding mountain travel altogether, as snow levels could fall as low as 3,000 to 4,000 feet. As a result, icy conditions on major passes should be expected, including on Interstate 5 and State Routes 14, 2 and 33.
As of mid-morning Wednesday, the Grapevine is still open, while State Route 2 is closed from Mt. Wilson Road to Big Pines Highway.
*State Route 2 in Angeles National Forest*
— Caltrans District 7 (@CaltransDist7) March 28, 2023
SR-2 remains CLOSED from Mt. Wilson Rd. to Big Pines Hwy. Multiple slides west of SR-39 & collapsed roadway at post mile 46/Windy Gap. Unknown duration. Updates at https://t.co/O37QesJHpw. pic.twitter.com/zNkhufJEI5
Six to 10 inches of snow could fall above 5,000 feet, though some mountain peaks could to see up to 18 inches.
There's a winter storm watch in effect for the area as whiteout conditions are a concern. Wind gusts could reach 45 miles per hour in some spots.
The lower elevation snow at places like the Grapevine will mostly be a concern Thursday morning, which is when as much of an inch of snow could fall.
As snowfall is anticipated again along the I-5 #Grapevine, Caltrans snowplow crews are monitoring for potential ice or sticking snow. Please avoid unnecessary travel or anticipate travel delays during the storm. Visit https://t.co/xbyTKr2hic for closure updates. pic.twitter.com/W9aX5jQDeQ
— Caltrans District 7 (@CaltransDist7) March 29, 2023
Last week's storm produced some notable damage including a pair of tornadoes, and a collapsed hillside in Pacific Palisades.
Roadway safety experts advised motorists to:
State law requires residential units to have heating systems that can keep indoor temperatures at a minimum of 70 degrees. That means every dwelling unit and guest room offered for rent or lease should offer heating equipment, usually central air conditioning (A/C) or a wall heater. — Caitlin Hernández
Use heat smartly to save money: Cranking things like the A/C and wall heaters can be expensive. If money is tight, be judicious about how and when you use your utilities. For example, only use heaters at night or only set the thermostat to around 70 degrees.
Open and close those vents: If you have central A/C, look at where the vents are around your home. Are any open in places where you don’t stay long? Practice opening and closing those so warm air only goes where you need it (most vents should have a small toggle lever). Humidifiers can also help you warm things up — and it’s useful to add moisture into our dry air.
Adjust your wall heaters: If you have a wall heater, you can change the output by adjusting the knob (usually at the bottom). Since wall heaters can only warm the areas where they’re placed, it’s essential to close doors to rooms you won’t be in so hot air doesn’t get wasted.
Turn on your ceiling fan (really): If you have a ceiling fan, try turning it on. This sounds counterintuitive, but there’s science behind it. The direction a fan turns can push air in different directions, and since hot air floats up, you’ll want to move that around. Your fan should spin clockwise to create an updraft to circulate. Not all fans will have this option, though.
Here's what you need to know when storms hit Southern California:
