Tropical Storm Mario remnants bring heavy rain, flash flood potential to San Diego

Dante Ulanday - News Moderator Dante Ulanday - News Moderator
Sep 16, 2025 - 21:45
Tropical Storm Mario remnants bring heavy rain, flash flood potential to San Diego

SAN DIEGO (FOX 5/KUSI) -- As Tropical Storm Mario off the coast of Baja California weakens, the remnants are expected to bring heavy rain and thunderstorms to Southern California this week.

Rain and the chance of thunderstorms moves into the region on Wednesday, with the highest chances of rain in San Diego County expected Wednesday night into Thursday, according to the National Weather Service in San Diego.

Tropical Storm Mario off the southern tip of Baja California has weakened to a remnant low and the moisture will bring storms to the southwestern U.S. by Thursday, the National Hurricane Center reports.

Rain chances on Wednesday will be between 20 and 30% from San Ysidro north to Oceanside and east into the deserts and mountains. Chances increase to 40 to 50% across San Diego County Wednesday night into Thursday morning with 30 mph winds expected.

Rain and storm chances will linger Wednesday night into Thursday morning (PHOTO: National Weather Service)
Rain and storm chances will linger Wednesday night into Thursday morning (PHOTO: National Weather Service)
Moisture from Tropical Storm Mario will increase chances for rain and storms beginning Wednesday afternoon (PHOTO: National Weather Service)
Moisture from Tropical Storm Mario will increase chances for rain and storms beginning Wednesday afternoon (PHOTO: National Weather Service)
High temperatures for inland areas will slowly cool through Friday (PHOTO: National Weather Service)
High temperatures for inland areas will slowly cool through Friday (PHOTO: National Weather Service)

Then on Thursday, rain chances increase even more -- from 50 to 60% -- until the remnants from the tropical storm fully dissipate.

Rain and storm chances peak by Thursday afternoon with the highest chances over the mountains (PHOTO: National Weather Service)
Rain and storm chances peak by Thursday afternoon with the highest chances over the mountains (PHOTO: National Weather Service)
Overcast skies, rain and storms will help to cool high temperatures Thursday afternoon (PHOTO: National Weather Service)
Overcast skies, rain and storms will help to cool high temperatures Thursday afternoon (PHOTO: National Weather Service)

The County of San Diego Public Works is warning residents the heavy rain could bring the potential for flash flooding. Turn around, don't drown when driving near flooded roads. Learn more about preparing for a flood, what to do during a flood, after a flood, and flood insurance facts at ready.gov/floods.

Rain and storm chances increase as moisture from Tropical Storm Mario filters into the area. Take caution as you make your commute to and from work as roads may become slick from rain. (PHOTO: National Weather Service)
Rain and storm chances increase as moisture from Tropical Storm Mario filters into the area. Take caution as you make your commute to and from work as roads may become slick from rain. (PHOTO: National Weather Service)

Full forecast fox5sandiego.com/weather

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