SAN DIEGO (CNS) - A flood watch is in effect for the San Diego County coastal areas, valleys and mountains through Tuesday evening due to excessive rainfall expected through the day with isolated afternoon thunderstorms.
Rainfall rates are anticipated to be a half inch per hour with higher rainfall rates on coastal mountain slopes.
Excessive runoff could result in flooding of rivers, creeks, streams, and other low-lying flood-prone locations. Debris flows and flash flooding are possible near recent burn areas, including Apple, El Dorado and Bond.
The forecast calls for rainfall to reach 1 to 1.5 inches west of the mountains and 2 to 3 inches along the San Diego County mountains below 5,000 feet.
PINPOINT WEATHER FORECAST | CHECK TRAFFIC CONDITIONS
The dynamic storm is forecast to move inland, the National Weather Service said. Periods of moderate to heavy rain and snow were expected to move in from the northwest Tuesday morning and continue through the early evening before the system rapidly ejects to the east, forecasters said.
Periods of damaging winds were likely across the region.
Rainfall totals could reach an inch over some parts of the high deserts as well, which can cause flooding where water is unable to drain properly on roadways.
Above 6,000 feet, heavy snow was possible, but the snow level will fluctuate and likely be above 7,000 feet until late Tuesday evening, forecasters said.
No hazardous marine conditions were expected through Tuesday morning, but southerly winds were predicted to increase Tuesday ahead of the storm, becoming west-northwest late Tuesday afternoon after a cold front passes. Wind gusts between 25 and 37 knots, combined seas of 8-10 feet, and rough seas were likely, producing conditions hazardous to small craft late Tuesday through early Wednesday.
The potential for gale force winds Tuesday afternoon and evening was increasing, and a gale watch was issued for 4 a.m. through 4 a.m. Wednesday to cover the period of small craft and gale conditions.
At county beaches, a large fresh swell was forecast to produce elevated to high surf Tuesday afternoon through Wednesday morning. Rough, choppy surf of 4 to 7 feet was possible, with local sets as high as 8 to 9 feet in San Diego County. Surf was expected to lower through Wednesday.
Temperatures were expected to stay below average for the remainder of the week with another chance for some light precipitation late Thursday into Friday.