Porter Ranch, California

... High wind watch now in effect from Tuesday afternoon through
late Tuesday night...

The high wind watch is now in effect from Tuesday afternoon
through late Tuesday night.

* Timing: Tuesday afternoon and Tuesday night.

* Winds: north winds 30 to 40 mph with possible gusts to 60 mph.
Winds strongest below passes and canyons.

* Impacts: the gusty winds will make travel difficult for high
profile vehicles.

Precautionary/preparedness actions...

A high wind watch means there is the potential for a hazardous
high wind event. Sustained winds of at least 40 mph... or gusts of
58 mph or stronger may occur. Continue to monitor the latest
forecasts.

... 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.


Gomberg/asr