SAN DIEGO — A storm system coming from the Gulf of Alaska is expected to bring some rain and cold temperatures to San Diego County starting Sunday, the National Weather Service in San Diego said.

"It will be a bit cooler than average today and an increase in clouds into Monday," forecasters said Saturday, "as the marine layer deepens and a storm system approaches from the northwest."

Some rain could break out on Sunday, but the best chance for heavy rain and high mountain snow will come on Monday and Tuesday, the NWS said.

"Periods of rain and snow showers will continue through midweek before this slow-moving storm exits the region," forecasters said. "Temperatures will be well below average until next weekend, when high pressure builds from the west."

High temperatures along the coast were expected to be between 63 degrees and 68 degrees, the NWS said. Inland high temperatures are predicted to be between 65 degrees and 70 degrees. The mountain low temperatures could be between 59 degrees and 65 degrees, the weather service said.

"For snow, it looks like it will be heavy at times above 5,500 feet and a Winter Storm Watch has been posted from Sunday night through Wednesday night," the NWS said. "So far, next weekend looks dry and warmer."

There is a slight chance of thunderstorms over the coastal waters Monday night into Tuesday morning, and again Wednesday afternoon and evening, forecasters said. The cold front will produce gusty southwest winds 20-25 knots over coastal waters on Monday, they said.

SUNDAY MICROCLIMATE HIGHS:

  • Coastal highs near 64°, seasonal norm: 67°
  • Inland highs near 64°, seasonal norm: 74°
  • Mountain highs near 55°, seasonal norm: 59°
  • Desert highs near 75°, seasonal norm: 82°