SAN FRANCISCO -- A low front spinning off the Northern California coast combined with moist air streaming up from the Hawaii Islands Sunday, fueling a potent winter storm that threatened to dump several inches of rain on the Bay Area.

According to the National Weather Service, the showers were particularly heavy in the North Bay where 2 inches of rain had already fallen at Cazadero in the northwestern part of Sonoma County.

San Rafael had gotten 1.11 inches between 3-9 a.m. St. Helena received 1.32 inches over the same time span while 0.31 inches had fallen in San Francisco and 0.33 inches in Oakland.

Forecasters warned local residents to be on the lookout for localized flooding as the rains of February had saturated the once drought parched soil.

At San Francisco International, the storm was creating havoc for travelers. Airport officials warned that flight delays up to an hour could be expected after noon Sunday due to the rainy weather.

Forecasters said periods of rain were expected to continue across the region through Monday, with locally heavy rain likely today across southwest-facing slopes in the coastal mountain ranges.

Locally gusty south winds are also expected through Monday, according to the weather service.

The storm comes after parts of the Bay Area absorbed up to 11 inches in some areas since the start of the month, causing easier runoff and also raising the possibility of mudslides and sliding rocks, according to the weather service.