SAN DIEGO (KGTV) — San Diego County is bracing for a stormy weekend as Tropical Storm Rachel approaches Baja California, bringing the potential for heavy rainfall, damaging wind gusts, flash flooding and dangerous coastal conditions.
According to the National Weather Service, the most significant impacts are expected to begin late Saturday night and continue into Sunday, with another round of lighter rain possible Monday into early Tuesday.
Although the center of Rachel is expected to remain south of the U.S.-Mexico border, its tropical moisture could produce significant impacts across Southern California.
When will the heaviest rain arrive?
Most of Saturday is expected to remain dry across San Diego County, with increasing cloud cover and a slight chance of isolated thunderstorms in the mountains and deserts during the afternoon.
The main band of rain is forecast to arrive in San Diego County between 10 p.m. Saturday and midnight, spreading northward across Southern California between 1 a.m. and 4 a.m. Sunday.
Sunday morning is expected to bring some of the most widespread rainfall, with periods of moderate to locally heavy rain.
Along the coast, the steadier rainfall should begin breaking into scattered showers between 8 a.m. and 11 a.m. Sunday.
By Sunday afternoon, most coastal and inland communities should see more isolated showers, although steady rainfall could continue in the foothills and along coastal-facing mountain slopes through Sunday evening.
How much rain could San Diego receive?
Under the most likely storm scenario, which the National Weather Service assigns approximately a 60% probability, San Diego County could receive:
- Coast and inland valleys: 0.75 to 1.5 inches of rain
- Foothills: Around 2 inches
- Mountains: 2 to 3 inches
- Deserts and desert slopes: Generally 0.5 to 1.5 inches
Rainfall rates in the mountains could reach half an inch to one inch per hour, increasing the risk of flash flooding.
Forecasters caution that rainfall totals remain uncertain and will depend heavily on Rachel's eventual track.
If the storm moves closer to San Diego, rainfall totals could climb to 1.25 to 2.5 inches across the coastal basin and 3 to 4 inches in the mountains.
A Flood Watch is in effect from Saturday evening through Sunday evening for San Diego County.
Residents should be especially cautious around flood-prone roads, low-water crossings, canyons and areas near creeks and streams.
Strong winds could create additional hazards
Along with heavy rainfall, Tropical Storm Rachel could bring strong wind gusts beginning early Sunday morning.
Under the most likely wind scenario, coastal communities and inland valleys could experience gusts between 25 and 45 mph.
Mountain ridges and desert slopes could see significantly stronger winds, with gusts reaching 50 to 70 mph.
These winds could make travel difficult, especially for high-profile vehicles, and potentially bring down tree branches or unsecured outdoor objects.
The strongest winds are expected Sunday morning into the afternoon before gradually weakening Sunday evening.
A Tropical Storm Watch is in effect across San Diego County.
Dangerous surf and coastal flooding
San Diego's beaches face an additional threat as tropical storm swells combine with elevated tides and strong winds.
Surf is expected to build to 5 to 8 feet Sunday, with occasional sets reaching 9 feet.
Meanwhile, high tides between 7 and 7.5 feet could contribute to significant coastal flooding and beach erosion.
A Coastal Flood Warning remains in effect through 3 p.m. Sunday.
Beachgoers should avoid entering the water during hazardous conditions and stay away from exposed rocks, jetties and unstable coastal bluffs.
Strong rip currents will also create dangerous swimming conditions.
Although surf and winds should gradually weaken Monday and Tuesday, elevated tides and lingering swells could continue producing minor coastal flooding into Tuesday afternoon.
Another round of rain expected Monday
The wet weather will not necessarily end once Tropical Storm Rachel moves away.
A separate upper-level weather system moving southward into California is expected to bring another round of lighter rainfall Monday.
Most coastal and inland communities could receive an additional 0.05 to 0.25 inches, with higher totals possible in the mountains.
Light snow is also possible at elevations above approximately 8,000 feet.
Scattered showers could linger into Tuesday morning before conditions begin clearing Tuesday afternoon.
Significant cooldown before temperatures rebound
The storm systems will also bring a noticeable drop in temperatures across San Diego County.
Highs are expected to fall approximately 10 to 15 degrees by Sunday, with many coastal and inland communities reaching only the low 70s.
Monday will be even cooler, with highs generally in the 60s west of the mountains and temperatures falling into the 40s at higher mountain elevations.
Conditions should begin warming Tuesday, with a more significant warming trend developing during the second half of next week.
Seasonable temperatures are expected to return by the end of the week, with potentially much warmer weather next weekend.
San Diego County high temperatures
Saturday, October 10:
- Coast: Upper 70s
- Inland valleys: 80s
- Mountains: Exact range not specified in the forecast discussion
- Deserts: High deserts in the 80s; low deserts in the mid-90s
Sunday, October 11:
- Coast: Low 70s
- Inland valleys: Low 70s
- Mountains: 50s to low 60s
- Deserts: Exact range not specified in the forecast discussion
