National Weather Service tells us:
...THREAT OF BLACK ICE ACROSS THE MOUNTAINS...DESERTS...AND INTERIOR
VALLEY LOCATIONS TONIGHT... VERY COLD AIR COMING INTO SOUTHERN
CALIFORNIA TONIGHT IN THE WAKE OF A VIGOROUS COLD FRONT. SNOW LEVELS
WILL CONTINUE TO FALL QUICKLY TONIGHT...LOWERING TO AS LOW AS 1500 FEET
OVERNIGHT IN SOME AREAS. IN MANY LOCATIONS...THE PRECIPITATION WILL END
LATER THIS EVENING... WITH THE EXCEPTION OF THE NORTH SLOPES OF THE
MOUNTAINS...WHERE A WINTER STORM WARNING REMAINS IN EFFECT.
HOWEVER...THE INFLUX OF VERY COLD AIR WILL BRING THE THREAT OF BLACK
ICE ACROSS MANY INTERIOR SECTIONS OF SOUTHERN CALIFORNIA. THE GREATEST
THREAT OF ICY CONDITIONS WILL BE ACROSS THE MOUNTAINS AND ANTELOPE
VALLEY... BUT ALL INTERIOR VALLEY LOCATIONS WILL ALSO BE VULNERABLE TO
BLACK ICE CONDITIONS... INCLUDING WIND SHELTERED AREAS OF THE SANTA
CLARITA VALLEY...SAN FERNANDO VALLEY...AND VENTURA COUNTY VALLEYS.
Instruction:
MOTORISTS TRAVELLING INTO THE MOUNTAINS... DESERTS... AND INTERIOR
VALLEYS SHOULD BE PREPARED FOR SUB-FREEZING TEMPERATURES... VERY COLD
WIND CHILL READINGS... AND DANGEROUS BLACK ICE CONDITIONS. PLEASE
REFER TO THE LATEST WINTER STORM WARNING PRODUCT FOR DETAILS ON SNOW...
AND NON PRECIPITATION WEATHER PRODUCT FOR DETAILS ON UPCOMING FROST AND
FREEZE POTENTIAL.
Area: SAN LUIS OBISPO COUNTY CENTRAL COAST-SANTA BARBARA COUNTY
CENTRAL COAST-SANTA YNEZ VALLEY-SAN LUIS OBISPO COUNTY INTERIOR
VALLEYS-CUYAMA VALLEY-SANTA BARBARA COUNTY SOUTH COAST-VENTURA COUNTY
COAST-LOS ANGELES COUNTY COAST INCLUDING DOWNTOWN LOS ANGELES-VENTURA
COUNTY INTERIOR VALLEYS-VENTURA COUNTY COASTAL VALLEYS-SANTA MONICA
MOUNTAINS RECREATIONAL AREA-SAN LUIS OBISPO COUNTY MOUNTAINS-SANTA
BARBARA COUNTY MOUNTAINS-VENTURA COUNTY MOUNTAINS-LOS ANGELES COUNTY
MOUNTAINS EXCLUDING THE SANTA MONICA RANGE-ANTELOPE VALLEY-CATALINA
ISLAND-SANTA CLARITA VALLEY-LOS ANGELES COUNTY SAN FERNANDO VALLEY-LOS
ANGELES COUNTY SAN GABRIEL VALLEY-
