The Los Angeles region forecasts begin Tuesday, with hazardous weather conditions for thunderstorms, dry lightning and RIP current forecasts.
According to the National Weather Service, Interior Mountains in San Gabriel Mountains, Antelope Valley, Ventura and Santa Barbara County bring the latest thunderstorms and the latest thunderstorms throughout the region, and a quick read of Southern California coasts from Tuesday through Wednesday. The most likely windows for the storm are 2pm to 10pm on Tuesdays.
“With dry air near the surface, the thunderstorms that form can cause windings up to 50 mph, especially due to hilly areas and lower mountains, creating the possibility of dry lightning,” the Meteorological Bureau said. “As elevation increases, there is less risk of dry lightning, and the risk of short-term heavy rains is higher, with rain rates up to about 0.75 inches per hour.”
There is enough moisture in the atmosphere to cause thunderstorms to produce dry lightning, but the air near the ground is so dry that the sediment can evaporate, explained Rose Schenfeld, a meteorologist with the Meteorological Bureau. This dangerous weather event is the major natural cause of wildfires.
“In many cases, if you have lightning, it’s raining too, and the ground is wet, obviously there won’t be a fire,” Schoenfeld said. “What we’re sending here is that storm clouds can really not rain. So you can get lightning bolts that can hit dry ground and start a fire.”
She said higher elevation areas have a lower risk of experiencing dry lightning, as the rain travels to the ground shorter and therefore less time to evaporate.
This reduces the chances of fires starting in mountainous areas, but storms can cause flash floods and landslides in areas previously burned by wildfires. In particular, the Weather Service identified the scars of bridge burns in the Angeles National Forest and Eton Fire Burn Scar in Altadena on Tuesday as a risk of debris flow.
Along the coast there is another danger lurking. A south swell raises waves, rising to 6 feet tall, tearing rip currents. The National Weather Service will have Beach Hazardous Doves in Ventura County Beach and Los Angeles Beach on the Malibu coast until Tuesday afternoon.
“There is a higher risk of marine drowning,” the Meteorological Bureau said. “The RIP flow allows swimmers and surfers to be drawn into the ocean. The waves can wash people off the beach and rocks and mask small boats near the coast.”
The Weather Service also announced on Monday that it will officially take part in the fire high season operation and will begin publishing Southern California twice a day.
“We want people to start thinking about the next fire season,” Schoenfeld said. “It’s important for the public to start thinking about what they need to do to prepare their home, their family and their go-bags, learn evacuation routes and sign up to get emergency notifications.”
As the last heavy area rain event took place in March and the weather began to warm, the vegetation was dry and fuel beds were being made for the fire, she said. In summers when Southern California typically has slight rainfall and high temperatures, the weather risk of fires increases.
