SAN DIEGO — Another, colder storm is expected to hit San Diego County Sunday night with showers breaking out this evening and becoming widespread overnight through early Monday, the National Weather Service said.
In the mountains Sunday night, rain will turn to snow as very cold air pours in from the north, dropping snow levels to 2,000 to 3,000 feet, forecasters said.
Over the coastal waters, gale force winds and dangerous seas will develop with strong winds along the coast as well.
High temperatures along the coast Sunday were expected to be around 58 degrees, with lows of 42-47 and widespread showers overnight, the NWS said. Highs in the western valleys will be around 58. Near the foothills, highs will be 48-53 with overnight lows of 36-44 and heavy rainfall.
Mountain highs were expected to be 40-47 with overnight lows of 23-33 and five to seven inches of snow. Desert highs will be 61-66 with overnight lows of 39-48 and showers.
"The bulk of the precipitation will fall Sunday night through Monday morning, with snow levels lowering from around 4,000 feet Sunday, to around 2,000-2,500 feet by Monday afternoon," forecasters said.
Travel impacts are expected to be severe on Monday, with several inches of snow affecting all mountain areas and major passes such as Interstate 15, the Cajon Pass, and particularly Interstate 8, where snow may be heaviest. More minor accumulations were expected for lower elevation areas including the far inland valleys and the foothills of San Diego County, the NWS said.
The cold air mass aloft will contribute to an unstable environment and a chance of thunderstorms through Monday.
"In addition to the rain and snow, this system will pack a punch when it comes to winds," forecasters said. "This is especially the case for our coastal communities, particularly San Diego County coast, where sustained winds of 25 to 35 mph, and gusts to 50 mph, and locally even higher, can be expected on Monday, strongest in the afternoon."
This will be a significant wind event for the coast, the NWS said, as coastal zones are rarely impacted by winds this strong, so there is a high likelihood of downed trees and tree limbs, and damage to weak fencing.
The midweek period will feature quiet weather with gradual warming ahead of another large and slower-moving storm bringing heavy rain and mountain snow to northern and central portions of the state. That one could arrive in San Diego on Thursday night or Friday with more widespread rain and higher snow levels.
The following warnings and advisories were issued Sunday by the weather service:
-- A winter storm watch will be in effect from Sunday evening through Monday evening for San Diego County mountains.
-- A high surf advisory will be in effect from 6 a.m. Monday to 6 p.m. Tuesday for San Diego County coastal areas.
-- A small craft advisory will be in effect from noon Sunday to 2 a.m. Monday for coastal waters from San Mateo Point to the Mexican border and out to 30 nautical miles from San Mateo point to the Mexican border extending 30 to 60 nautical miles out including San Clemente Island.
-- A gale warning from 2 a.m. Monday to 10 p.m. Tuesday for coastal waters from San Mateo Point to the Mexican border and out to 30 nautical miles from San Mateo point to the Mexican border.
SUNDAY MICRO CLIMATE HIGHS:
- Coastal highs near 60°, seasonal norm: 65°
- Inland valley highs near 59°, seasonal norm: 66°
- Mountain highs near 45°, seasonal norm: 50°
- Desert highs near 60°, seasonal norm: 70°