Residents in the North County awoke to thunder, lightning and rain early Wednesday as a summer storm swept across San Diego County.
A cloud-to-water lightning strike has prompted lifeguards to warn beachgoers in Encinitas and the City of San Diego.
The National Weather Service has issued a warning for cloud to ground lightning at San Diego's Lindbergh Field.
People living near Camp Pendleton, Oceanside and Fallbrook have received moderate to heavy rain fall since around midnight with Fallbrook reporting half an inch of rain by 9 a.m.
"House shaking thunder here in San Elijo Hills!" Dena Everton posted to NBC 7's Facebook page.
"That was a loud alarm clock this morning! The loudest thunder we've heard in a long time! Loving nature!" Sandra Marie reports from her home in Vista.
Downtown resident Jodie Lehrer Booras enjoyed a "constant lightning show" while driving along I-5 on the way to Carlsbad before 6 a.m.
There have also been reports of hail. The National Weather Service said hail the size of nickels may fall.
A thunderstorm warning was issued for Riverside County north of Hemet through 9:30 a.m. PT.
A flash flood watch was in effect for the deserts and mountains through Wednesday evening, according to the NWS.
An urban and small stream flood advisory for San Diego County was also in effect through 9:15 a.m. PT. Minor flooding is possible due to the heavy rain over the burn scars of the recent fires on Camp Pendleton.
San Diego Lifeguards say city beaches are closed right now due to the threat of lightning. So lifeguards are asking beachgoers to leave the water.
They say they do not have the resources to actually remove people from the water. So, in reality it is a voluntary closure.
Encinitas lifeguards told NBC 7 they have not closed the beaches, but are warning people of the potential dangers from lightning strikes.
In July, a young man was killed on Venice Beach when he was struck by lightning along with seven others.
NBC 7 Meteorologist Jodi Kodesh said this storm is more indicative of a winterlike storm in that it's coming from the northwest.
The cold air clashing with our already warm air is creating a line of thunderstorms, she said.
Along the coast, just over a quarter of an inch of rain recorded in Carlsbad. A half an inch of rain was recorded in Santa Ysabel and just a trace of rain has fallen so far in Borrego Springs.
An area of low pressure will bring the entire county a 30 percent chance of showers or thunderstorms.
"Just know that we have the potential all day today to have a shower or thunderstorm," Kodesh said.
She adds that if you are in an area with thunder and lightning, be safe and head indoors.