SAN FRANCISCO (KRON) — A strong storm system in the Bay Area on Thursday is brought heavy rain, gusty winds, and flooding to the region.

The rain started in the North Bay and made its way south across the Bay Area by the afternoon. The rain has caused some urban flooding throughout the region and will have a major impact on the evening commute.

Drivers should be aware of slippery roads. Make sure to leave early, reduce your speed, and turn on your wipers and headlights.

A flash flood warning has been issued for Sonoma County and northern Marin County until 5 p.m., according to the National Weather Service.

A flood warning in Fairfield is in effect until 10 a.m. Friday.

A flash flood watch has been issued in parts of San Jose as well.

A high wind advisory has also been issued for all day Thursday due to the storm.

FORECAST:San Francisco Bay Area Weather

Incoming flight to San Francisco International Airports are experiencing delays of up to three hours due to low visibility.

So far Thursday, the airport has announced 85 cancellations, which are fairly evenly split between arrivals and departures and are mostly for short-haul flights along the West Coast, according to SFO spokesman Doug Yakel.

Delays are averaging between 60 and 90 minutes and could increase as the storm strengthens throughout the day.

Passengers are being urged to check with their airline for the most recent flight status updates, Yakel said.

Rainfall totals from the Wednesday night into Thursday are forecast to range from 2″-4″ with higher amounts along the coastal mountains and higher elevations across the North Bay.

In San Rafael, several streets are flooded and creeks are overflowing, including on Highway 37.  The weather service also issued a minor to moderate flood warning at 2 p.m. for the Napa River Basin near St. Helena, forecaster Bob Benjamin said. That alert has since been canceled.

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The Napa River at St. Helena was at about 14 feet at 2 p.m. and was expected to rise above flood stage at 17.7 feet early Thursday evening, then fall later in the evening, Benjamin said.

Major flooding occurs at 19 feet, he said.

Sonoma County officials reported 24 road closures throughout the day that included Austin Creek Road in Cazadero, Eastside Road in Windsor, Freestone Flat Road and Green Valley Road in the Sebastopol area, Mark West Station Road north of Santa Rosa, Valley Ford Road in the Valley Ford area and the western portion of Rohnert Park Expressway to Stony Point Road.A large tree fell and blocked Calistoga Road at Alpine Road in

A large tree fell and blocked Calistoga Road at Alpine Road in Sonoma County, according to the CHP.

Most urban areas from San Francisco southward can expect between 3/4″ to 1 1/2″ as the system rapidly moves across the region.

The storm has also caused king tides, the naturally occurring and very high tides that can contribute to flooding, along coastal areas and near creeks and estuaries.

The high tide at the Golden Gate Bridge will arrive around noon Thursday, just as the heaviest rains are expected, according to the weather service.

Forecasters have issued flash-flood warnings for the areas burned by the Loma and Soberanes fires and say drought-weakened trees are particularly vulnerable to being downed and could result in power outages around the region.

Showers may linger into Friday, but dry conditions are expected to return by the weekend.

Rainfall is expected to be particularly hazardous in areas of Santa Clara and Monterey counties where the Loma and Soberanes fires burned earlier this year. The weather service said heavy rain could result in an increased threat of flash floods, debris flows and mudslides.

Vacaville police have provided a link to where you can check creek levels.

Flash flood advisories were issued for areas of Lake County burned by wildfires in the summer, according to Benjamin.

The Venado rain gauge in Sonoma County west of Healdsburg recorded 6.44 inches of rain at 11 a.m., and gauges in the Monte Rio area recorded between 3.68 and 4.25 inches of rain, Benjamin said.

The heaviest rain in northern Sonoma County has subsided and the storm was moving south toward San Francisco, Benjamin said.

EVACUATIONS:

Flooded homes are reported in Marin County’s San Geronimo Valley in Forest Knolls and Woodacre. Evacuations are in place along Castro Street.

The San Geronimo Community Center, at 6350 Sir Francis Drake Blvd, has opened its doors for persons who have temporarily left their homes.ROAD CLOSURES:

Highway 1 between Pt Reyes Station to Olema reported as currently “impassible” by sheriff’s deputies due to flooding.

Lucas Valley Road is closed in Marin Co., about a half mile west of Big Rock through Friday morning.

A traffic alert has been issued for Hwy 113 east of Vacaville due to flooding. Road closed in both directions.

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