Hard to believe, as it’s 83 degrees out at six PM with no cloud in the sky, but hear it from the National Weather Service:

SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE OXNARD CA 440 PM PDT SAT JUL 12 2008

THE NATIONAL WEATHER SERVICE IN OXNARD HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR… EAST CENTRAL LOS ANGELES COUNTY IN SOUTHWEST CALIFORNIA…

* UNTIL 545 PM PDT

* AT 429 PM PDT…NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL…AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED 12 MILES EAST OF PEARBLOSSOM…OR ABOUT 25 MILES NORTH OF UPLAND…AND MOVING WEST AT 6 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR… PEARBLOSSOM BY 545 PM PDT…

THIS STORM WILL AFFECT TRAVELERS AND COMMUNITIES ALONG HIGHWAY 138. IN ADDITION TO LARGE HAIL AND DAMAGING WINDS…CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS IMMEDIATELY! LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.

And this:
THE NATIONAL WEATHER SERVICE IN OXNARD HAS ISSUED A

* FLASH FLOOD WARNING FOR… EAST CENTRAL LOS ANGELES COUNTY IN SOUTHWEST CALIFORNIA INCLUDING THE EASTERN ANTELOPE VALLEY AND EASTERN SAN GABRIELS…

* UNTIL 600 PM PDT

* AT 423 PM PDT…DOPPLER RADAR INDICATED A STRONG CLUSTER OF THUNDERSTORMS THAT WILL LIKELY PRODUCE FLASH FLOODING ACROSS EAST CENTRAL LOS ANGELES COUNTY…AFFECTING EXTREME EASTERN ANTELOPE VALLEY ALONG HIGHWAYS 18 AND 138…AS WELL AS THE EASTERN SAN GABRIELS…INCLUDING THE COMMUNITIES OF BIG PINES…FALLING SPRINGS AND MOUNT BALDY. THESE STORMS WERE DRIFTING SLOWLY TO THE SOUTHWEST AND WILL LIKELY PRODUCE RAINFALL INTENSITIES OF ONE INCH PER HOUR.

IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY. RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE PRECAUTIONS TO PROTECT LIFE AND PROPERTY.

DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. ONLY A FEW INCHES OF RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR VEHICLE.