BORREGO SPRINGS (CNS) - A strong thunderstorm was expected to bring brief road flooding, penny-sized hail and 50 mph winds to Borrego Springs and Agua Caliente Springs today, according to the National Weather Service.
The storm was centered 6 miles northeast of Mount Laguna by National Weather Service observers at 4:24 p.m., and was one of many intense, scattered thunderstorms that swept San Diego County today.
Tomorrow will bring the same.
The inland mountains will get most of the rain, said Noel Isla, a meteorologist with the National Weather Service.
The valleys have only a slight chance of showers, but are forecast to get lots of lightning, he said.
A moist, low pressure system centered off the coast of central California hit the high pressure inland system spun subtropical moisture into the county, causing unseasonal weather, the NWS said.
"This monsoon moisture should've ended mid-September, but we're getting it now," Isla said.
No flash flood warnings are in effect in San Diego County, but rains bring the threat of heavy debris flows near recently burned areas, he said.
The tropical system moved from the coast of Baja California to its current location over the last two days and is forecast to keep moving north, the NWS said.
The NWS warned hikers against venturing into narrow canyons that can be flooded, since runoff from distant storms can suddenly inundate normally dry washes.
People should stay indoors when they see lightning nearby, Isla said.