Thunderstorms capable of producing heavy rain and flash flooding are expected in San Diego County’s mountains and deserts again Monday, as are strong rip currents and elevated surf along the coastline, forecasters said.
A National Weather Service flash flood watch will remain in effect through Monday evening in the mountains and deserts, as a deep monsoonal flow in the atmosphere draws moisture from the subtropics north through Southern California.
The main threat for flooding will be late Monday morning through early afternoon near mountain slopes and foothills, and across the deserts, forecasters said. The risk of flash flooding will be the greatest in steep canyons, downstream from mountain slopes and in areas recently denuded by wildfire, where runoff and debris can quickly fill dry washes.
“Due to the rich moisture supply, heating over the mountains each day will result in thunderstorms capable of torrential rain and local flash flooding,” according to a weather service statement.
Forecasters said more than three inches of rain could fall in some areas and flooding would be likely near slow-moving thunderstorms.
Flash flooding can develop miles from a thunderstorm and can lead to dangerous flows in normally dry creek beds, forecasters said.
A beach hazards statement for the county’s coastal areas for rip currents and 4- to 6-foot surf with sets of up to 8 feet resulting from a swell generated by Tropical Storm Norbert is set to expire late Monday. Minor coastal flooding could be possible at high tide.
“The elevated surf and large tidal swings will mean strong rip and long shore currents at area beaches,” according to the weather service. “Swell and surf will decrease late tonight.”
The currents could result in dangerous swimming conditions, especially for those with little experience in the water, according to the weather service. Beachgoers were advised to obey posted warning signs, use caution in and around the water and to swim near a lifeguard.
— City News Service
