We’re keeping this at the top of the page today.

UPDATE 3 PM: Well, after a white-knuckle drive to pick our son up from school in Sierra Madre (facing floods, thunder, and hail along the way), we’re back …

Via Alice Wesson, a real-time webcam of the Arroyo Seco flow:

http://ca.water.usgs.gov/webcams/jpl/webcam-oper.html

and National Weather service says were are now in flash flood warning mode:

…A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 PM PST FOR THE STATION…MORRIS…AND SANTA ANITA BURN AREAS IN CENTRAL LOS ANGELES COUNTY…

AT 205 PM PST…DOPPLER RADAR INDICATED A LINE OF INTENSIFYING THUNDERSTORM ACTIVITY EXTENDING FROM DOWNTOWN LOS ANGELES NORTHEASTWARD INTO THE MORRIS BURN AREA. THIS LINE OF INTENSE STORMS WAS MOVING SLOWLY NORTHEAST…AND WILL LIKELY IMPACT THE STATION BURN AREA BY 230 PM. VERY INTENSE RAINFALL RATES HAVE BEEN OBSERVED NEAR THE MORRIS BURN AREA…WITH SAN GABRIEL DAM REPORTING .48 INCHES IN 15 MINUTES. THE HEAVY RAINFALL RATES WILL LIKELY GENERATE FLASH FLOODING AND DEBRIS FLOWS IN THE BURN AREAS THROUGH 5 PM.

PRECAUTIONARY/PREPAREDNESS ACTIONS…

RESIDENTS AND MOTORISTS IN AND BELOW RECENTLY BURNED AREAS SHOULD BE ALERT TO FLASH FLOODING AND DEBRIS FLOWS WHICH MAY BLOCK ROADS AND CULVERTS.

UPDATE 1:30 PM: CERT Volunteers requested to be on standby: From the sheriff’s station:

Because of the current storm event, the Altadena Sheriff’s Station is on standby if Incident Command requests CERT trained volunteers to report for duty.

If you are a CERT trained volunteer and can report for duty within two hours of being notified, please call Sergeant Dan Bartlett or Deputy Michael Prince at the Altadena Sheriff’s Station – 626 798 1131, to let them know what your availability is.

If the CERT volunteers are asked to assist, you will be required to show up at Descanso Gardens in LaCanada at a designated time.

We don’t know when that call may come, or that it will, but CERT volunteers should be on standby today, tonight and tomorrow.

Please understand, you must already be a CERT trained volunteer and must be available to report to the command post within two hours of notification.

If you’re willing and available, please contact Sergeant Bartlett or Deputy Prince.

UPDATE NOON: Another missive from Gino Sund — and Meadows residents better check on their stocks of groceries:

There is an unstable cold front heading West that has the potential for heavy to intense showers and thunderstorms starting around noon or before.

There is a high probability that a blockage will occur at Canyon Crest Road which will result in a road closure.  There is no evacuation of the Meadows, and residents are advised to shelter in place.  An unmanned Fire engine is stationed in the neighborhood with a crew prepared to hike in to operate the equipment if necessary.