SAN DIEGO – A weekend of wild weather swings is on tap: cool to cold temperatures, powerful west winds in the mountains and deserts, the first Santa Ana of the season, and maybe even a smattering of rain.

A powerful low-pressure system, called an “inside slider” because it took an inland route as it dropped south from Alaska, should be near Southern California late Friday.

The low is expected to kick up strong winds in the mountains and deserts, where a high-wind warning will be in effect from 6 p.m. Friday to 6 a.m. Saturday. Blowing sand and dust could reduce visibility in the deserts, and driving could be difficult for high-profile vehicles.

That same low pressure could bring light showers throughout the county late Friday or early Saturday. The National Weather Service does not expect the rainfall to amount to more than a few hundredths of an inch.

Once the low moves out to the east, temperatures could drop to the lowest levels in six months. Sunday morning, San Diego could be in the low 50s, and Mount Laguna could drop into the high 20s.

Later Sunday, the weather is expected to change dramatically. The air should dry out and warm up, and the winds should shift to out of the northeast – the typical Santa Ana pattern.

Weather service meteorologist James Oh said a red-flag warning signifying high fire danger is likely to take affect Sunday afternoon or evening for the county's mountains. Sustained winds of 30 to 40 mph are expected at the peak early Monday, and gusts could top 50 mph.

The winds are not expected to be as strong in the inland valleys and at the coast, but 25 mph gusts are possible. The winds should die down by Tuesday afternoon.

The coast is expected to continue its temperature roller-coaster ride. San Diego, which was 24 degrees cooler Thursday (70) than Wednesday (94), should cool off more Friday and Saturday, when highs are expected to be in the 60s. By Monday, highs could be back up near 80.

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