Southern California is in for a wild week of weather, with thunderstorms and toasty temperatures bringing both the chance of fire starts and sudden downpours, forecasters say.
Tuesday is expected to be the hottest day of the week, with warmer valley areas in L.A. County expected to reach the triple digits and temperatures in inland coastal areas ranging from the 80s to lower 90s, according to the National Weather Service. The hot weather will continue on Wednesday and coincide with a risk of thunderstorms that will persist through midday Friday.
The storms bring the chance of lightning-sparked fires in areas with high temperatures and dry vegetation. But the storms also bring the possibility of brief, heavy downpours and isolated strong winds, according to the weather service.
“Unfortunately, there’s a lot of uncertainty with the thunderstorms,” said meteorologist Kristan Lund. “We have a lot of different things at play — we have a ridge of high pressure building to our east, a low pressure system dropping out of the northwest, and we have Tropical Storm Mario coming up from the south.”
The confluence of these different pressure systems has resulted in fluctuations in forecast models that make it hard to predict exactly where in Southern California thunder, lightning and rain will land, she said.
From Tuesday night through midday Friday, there is a 15% to 25% chance of thunderstorms and a 60% to 90% chance of showers anywhere in L.A. County, according to the weather service.
The window when the danger of thunderstorms and lightning is expected to be greatest is Wednesday morning through Thursday morning.
“With those storms, we can have wind shifting and being really strong all of a sudden, frequent lightning, and we can see brief, heavy downpours,” said Lund. “We don’t want to rule out the possibility of some dry fire starts because lightning can occur away from the rain core.”
If residents hear thunder, they are advised to seek shelter immediately, especially when at the beach or other open spaces.
Thursday is expected to be the wettest day of the week; however, models vary widely when it comes to the total amount of rainfall predicted.
There is the possibility of a tenth of an inch of rain to half an inch of rain, but there is also the possibility of twice that amount — or no rain at all — according to current models.
“There’s a high risk for wet outdoor events, especially on Thursday. There’s moderate risk for minor urban and roadway flooding, and there’s a low risk for significant flooding and debris flows,” said Lund.
The threat of showers and thunderstorms is expected to continue through at least the first half of Friday before the turbulent weather gives way to a mellow, dry weekend. Elevated temperatures are predicted to drop back down to seasonal norms by Saturday.
