Alert archive / California / Flash Flood Warnings in 2011
Flash Flood Warning 2, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this flash flood warning at Mar 24, 2011, 3:08 PM PDT for Santa Cruz County, California. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.
The area
The outline as issued.
The facts
- Issued
- Mar 24, 2011, 3:08 PM PDT (22:08 UTC)
- Expired
- Mar 24, 2011, 5:45 PM PDT
- In force
- 3 hr
- Issued by
- NWS San Francisco Bay Area, CA
- Area
- Storm-based polygon
- Flood severity
- None
County Santa Cruz County, CA
The radar
The San Francisco radar (KMUX), 20 km from the middle of the area, began a volume at 22:11 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Oakland, CA (KOAK), launched 12:00Z, 10.1 hours before the alert went out and 79 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 152 J/kg
- Mixed-layer CIN
- -6 J/kg
- Mixed-layer LCL
- 587 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 121 m²/s²
- 0-3 km storm-relative helicity
- 154 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
883
WGUS56 KMTR 242208
FFWMTR
CAC087-250000-
/O.NEW.KMTR.FF.W.0002.110324T2208Z-110325T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
308 PM PDT THU MAR 24 2011
THE NATIONAL WEATHER SERVICE IN THE SAN FRANCISCO BAY AREA HAS
ISSUED A
* FLASH FLOOD WARNING FOR...
THE SAN LORENZO RIVER IN SANTA CRUZ COUNTY IN WESTERN CALIFORNIA...
* UNTIL 500 PM PDT.
* AT 303 PM PDT...NWS DOPPLER RADAR AND AUTOMATED RAIN GAGES
INDICATED HEAVY RAINFALL MOVING THROUGH THE AREA OVER THE LAST
HOUR AND A HALF. THE SAN LORENZO RIVER AT BIG TREES GAGE
LOCATION IS NOW AT JUST UNDER FLOOD STAGE OF 18 FEET AND IS
EXPECTED TO EXCEED THAT WITHIN THE NEXT HOUR. RAINFALL IS
EXPECTED TO TAPER OFF AFTER ANOTHER HOUR OR SO BUT THE RIVER COULD
STAY OVER FLOOD STAGE FOR THAT TIME.
* LOCATIONS IN THE WARNING INCLUDE COMMUNITIES AND INTERESTS ALONG
THE SAN LORENZO RIVER.
A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT.
RUNOFF FROM HEAVY RAINFALL WILL CAUSE LOCALIZED FLOODING OF SMALL
CREEKS AND STREAMS AS WELL AS ROADWAYS...UNDERPASSES AND OTHER LOW
LYING SPOTS. DO NOT ATTEMPT TO CROSS SWIFTLY FLOWING WATER OR WATER
OF UNKNOWN DEPTH. TURN AROUND...DONT DROWN.
IT IS IMPORTANT FOR CAMPERS AND HIKERS TO KNOW WHERE THEY ARE
RELATIVE TO CREEKS...STREAMS...OR RIVERS WHICH CAN BECOME DANGEROUS
IN HEAVY RAINS. BE PARTICULARLY AWARE IN HILLY TERRAIN WHERE MANY LOW
WATER CROSSINGS CAN QUICKLY BECOME KILLERS.
TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE.
LAT...LON 3712 12208 3695 12199 3694 12204 3695 12205
3711 12213
$$
WJK2 follow-up statements
584
WGUS56 KMTR 242357
FFWMTR
CAC087-250100-
/O.EXT.KMTR.FF.W.0002.000000T0000Z-110325T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
457 PM PDT THU MAR 24 2011
THE NATIONAL WEATHER SERVICE IN THE SAN FRANCISCO BAY AREA HAS
EXTENDED THE
* FLASH FLOOD WARNING FOR...
THE SAN LORENZO RIVER IN SANTA CRUZ COUNTY IN WESTERN CALIFORNIA...
* UNTIL 600 PM PDT.
* AT 455 PM PDT...THE SAN LORENZO RIVER AT BIG TREES WAS STILL JUST
OVER FLOOD STAGE AND AT 18.3 FEET. THE RIVER HAS CRESTED AND IS
SLOWLY ON ITS WAY DOWN BUT WILL TAKE APPROXIMATLY ANOTHER HOUR TO
DROP BELOW FLOOD STAGE.
* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO FELTON AND
BEN LOMOND
A FLASH FLOOD WARNING MEANS THAT FLOODING IS OCCURRING OR IS
IMMINENT.
TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE.
LAT...LON 3712 12208 3695 12199 3694 12204 3695 12205
3711 12213
$$
WJK041 WGUS76 KMTR 250045 FFSMTR FLASH FLOOD STATEMENT NATIONAL WEATHER SERVICE SAN FRANCISCO CA 545 PM PDT THU MAR 24 2011 CAC087-250053- /O.CAN.KMTR.FF.W.0002.000000T0000Z-110325T0100Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ SANTA CRUZ CA- 545 PM PDT THU MAR 24 2011 ...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR THE SAN LORENZO RIVER IN SANTA CRUZ COUNTY... THE SAN LORENZO RIVER AT BIG TREES IS BELOW THE FLOOD STAGE OF 18 FEET AND IS CURRENTLY AT 17.1 FEET AND CONTINUING TO RECEDE. WHILE ADDITIONAL SHOWERS MAY DEVELOP OVER THE NEXT FEW HOURS OF THE EVENING...RENEWED RISES ON THE SAN LORENZO TO FLOOD STAGE AGAIN IS NOT EXPECTED. THEREFORE THE FLASH FLOOD WARNING IS CANCELLED. LAT...LON 3712 12208 3695 12199 3694 12204 3695 12205 3711 12213 $$ WJK
The office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 23, 10:27 PM PDT | Areal Flood Advisory | MTR | Monterey, San Benito, Santa Clara, Santa Cruz | 19 hr |
| Mar 24, 3:45 AM PDT | High Surf Advisory | MTR | Marin, Monterey, City and County of San Francisco, San Mateo, Santa Cruz, Sonoma | 20 hr |
| Mar 24, 12:06 PM PDT | Special Weather Statement | MTR | San Mateo | 39 min |
| Mar 24, 2:55 PM PDT | High Surf Warning | MTR | Marin, Monterey, City and County of San Francisco, San Mateo, Santa Cruz, Sonoma | 24 hr |
| Mar 24, 3:05 PM PDT | Small Craft Advisory | MTR | 42 hr | |
| Mar 24, 4:04 PM PDT | Flash Flood Warning | MTR | Santa Cruz | 56 min |
Nearby
Flash Flood Warnings in California, 2011Every flash flood warning in 2011
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.