A dynamic storm was forecast to generate strong winds and significant precipitation across San Diego County as it moves inland Tuesday, the National Weather Service said Sunday.
“A storm will arrive Tuesday morning, bringing windy and wet weather,” the weather service said. “Rain will be heavy at times, with heavy snow in the mountains.”
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 also likely across the region during the storm.
Ample moisture and instability could produce very heavy rainfall, and even a few thunderstorms, resulting in periods of urban flooding and possible debris flows near and below recent burn scars as well as elsewhere on steep terrain. Current indications indicate a half-inch per hour Tuesday morning and afternoon.
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 is possible, but the snow level will fluctuate and likely be above 7,000 feet until late Tuesday night, forecasters said.
No hazardous marine conditions were expected through early Monday, but southerly winds were predicted to increase Monday through 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 are likely, producing conditions hazardous to small craft late Monday 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. Tuesday 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 4-7 feet was possible, with local sets as high as 8-9 feet in San Diego County. Surf was expected to lower through the day Wednesday.
As for Monday, cooler weather is expected with increasing clouds and a slight chance of showers in the afternoon.
High temperatures will be around 61 near the coast, 59 in the western valleys, 53 to 58 near the foothills, 49 to 56 in the mountains and 65 to 70 in the deserts.
Temperatures were expected to stay below average for the remainder of the week with another chance for some light precipitation late Thursday into Friday.
City News Service contributed to this article.