Tomorrow is forecast to be Much Cooler than today.
Forecast for Ventura County Coastal Valleys
Updated: 2:30 PM PST on December 21, 2009
Tonight
Mostly cloudy. A few sprinkles or light showers possible after midnight. Lows in the upper 30s and 40s. West winds around 15 mph after midnight. Chance of measurable rain 20 percent.
Tuesday
Partly cloudy in the morning then becoming mostly sunny. Windy. Highs in the mid 50s. Northwest winds 20 to 30 mph with gusts to 45 mph.
... Strong winds likely for the Southland Tuesday...
... Sub-freezing temperatures possible across portions of the Southland Tuesday night...
A cold and vigorous upper level low pressure system is expected to dig southward across interior California and Nevada overnight into Tuesday. Due to the expected inland track... this system will likely have limited moisture. A weak cold front is bringing scattered light showers to San Luis Obispo and northern Santa Barbara counties late this afternoon... with a slight chance of showers later this evening into early Tuesday morning for areas south of Point Conception. Any rainfall amounts with this system are expected to be fairly light... generally under a tenth of an inch... with the exception of local amounts up to one quarter inch across San Luis Obispo County.
Snow levels are expected to lower rapidly on Tuesday... generally falling to between 3500 and 4500 feet... with the exception of the north slopes which could see snow down to around 3000 feet. By Tuesday night... very cold air is expected to spread into the area... with snow levels potentially falling as low as 2000 feet. At this point... any threat of snow showers is expected to be confined to the north slopes near the Kern County line... but the expected cold temperatures could bring a threat of black ice to interior portions of the forecast area. A few inches of new snow will be possible across the north facing slopes... with accumulating snow possible along Interstate 5 near the Grapevine.
In addition to the threat of cold temperatures and low snow levels... this system will bring powerful winds across Southern California. In the wake of the front... strong and widespread northwest winds are expected across the region late Tuesday morning into the afternoon... with winds becoming more northerly by Tuesday evening. This system has strong upper level wind support... and could produce damaging wind gusts between 60 and 70 mph across the mountains... Antelope Valley... Santa Barbara South Coast... Santa Clarita valley... and San Fernando Valley. A high wind watch has already been posted for these areas. Many other portions of the Southland will likely require wind advisories... with wind gusts between 35 and 50 mph being common.
The influx of much colder air into the region Tuesday night will also bring the risk of sub-freezing temperatures to wind sheltered portions of southern and central California. Portions of the Antelope Valley... Cuyama Valley... and interior valleys of San Luis Obispo County are expected to have minimum temperatures fall into the lower to mid 20s... but these areas have already experienced two hard freezes this season. Other wind protected locations will likely have minimum temperatures fall into the upper 20s to lower 30s... with frost advisories possibly being issued.
Residents of Southern California are urged to stay tuned to the latest National Weather Service forecasts for this developing weather situation.