Much Cooler Temperatures, Rain Coming to Santee Wednesday

After the weekend's Santa Ana winds, much cooler temperatures and light rain are in store for Santee and San Diego County starting Wednesday, including a 100 percent chance of precipitation in Santee, according to the National Weather Service.

"A cold low pressure system will develop over the Pacific Northwest, then move quickly southward through Central California on Wednesday and through Southern California late Wednesday through early Thursday," the NWS said in an advisory.

High temperatures in the region will be 15 to 25 degrees below average for the time of year. 

NWS Forecast for Santee:

• Tuesday night: Increasing clouds, with a low around 56.
• Wednesday: A 40 percent chance of rain after 11am. Cloudy, with a high near 64. Southeast wind 5 to 10 mph becoming southwest 10 to 15 mph in the afternoon. Winds could gust as high as 30 mph.
• Wednesday Night: Showers, mainly before 11pm. Low around 53. West wind 10 to 15 mph, with gusts as high as 30 mph. Chance of precipitation is 100%.
• Thursday: A 20 percent chance of showers before 11am. Mostly sunny, with a high near 68. 

The weather service expects highs in the mid-50s to mid-60s in coastal and valley areas, mid-30s to mid-50s in the mountains, 60s in the upper deserts and 70s in the lower deserts.

Rainfall from the system was expected to range from one to two-tenths of an inch of rainfall near the coast to a quarter to three-quarters of an inch in the mountains.

The cold low pressure system was also expected to bring sustained 20 to 30 mile per hour westerly winds to the mountains and deserts, and widespread gusts of up to 50 mph. Isolated gusts up to 65 mph were also possible, the weather service said.

The agency issued a wind advisory for the mountains and deserts from 5 p.m. Tuesday to 5 a.m. Wednesday, and a high wind watch from late Tuesday night to late Wednesday night. 

A wind advisory means winds in excess of 35 mph are expected, while a high wind watch is issued when winds capable of causing property damage are expected or occurring.

"The winds will make driving difficult, especially for motorists with high profile vehicles," the weather service advisory said. "Watch for broken tree limbs and downed power lines."

Snowfall was possible in the county's highest peaks, though it would be a small amount, if any. 

The weather service said the snow level would drop to 5,500 to 6,000 feet Wednesday night through early Thursday, with a few inches of snowfall possible above 6,000 feet and around a half-foot above 7,000 feet.