Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 24, NWS San Diego, CA

August 17, 2012Riverside County, San Bernardino County, California

NWS San Diego, CA issued this flash flood warning at Aug 17, 2012, 1:07 PM PDT for Riverside County, San Bernardino County, California. It was in force for 3 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 17, 2012, 1:07 PM PDT (20:07 UTC)
Expired
Aug 17, 2012, 4:30 PM PDT
In force
3 hr
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

Counties Riverside County, CA, San Bernardino County, CA

The radar

The Santa Ana Mts radar (KSOX), 67 km from the middle of the area, began a volume at 20:07 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.

What was reported inside it

TimeReportWhereRemark
Aug 17, 2:16 PM PDTFLOODForest Falls, CAMILL CREEK TRIBUTARY...RATTLESNAKE CREEK...IS AT FLOOD STAGE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Edwards AFB, CA (KEDW), launched 12:00Z, 8.1 hours before the alert went out and 122 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.

Skew-T log-pSkew-T log-p diagram, Edwards AFB, CA at 12:00Z on 2012-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Edwards AFB, CA at 12:00Z on 2012-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -3 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3028 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-3 m²/s²
0-3 km storm-relative helicity
92 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

279 
WGUS56 KSGX 172007
FFWSGX
CAC065-071-172130-
/O.NEW.KSGX.FF.W.0024.120817T2007Z-120817T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
107 PM PDT FRI AUG 17 2012

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN RIVERSIDE COUNTY IN SOUTHERN CALIFORNIA...  
SOUTHWESTERN SAN BERNARDINO COUNTY IN SOUTHERN CALIFORNIA...THIS 
INCLUDES THE CITIES OF YUCAIPA AND CALIMESA...

* UNTIL 230 PM PDT

* AT 1258 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM A STORM OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO FOREST   
FALLS...OAK GLEN...AND EASTERN PARTS OF YUCAIPA AND CALIMESA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

&&

LAT...LON 3410 11701 3411 11683 3396 11688 3397 11708

$$

MM
5 follow-up statements
267 
WGUS76 KSGX 172043
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
143 PM PDT FRI AUG 17 2012

CAC065-071-172130-
/O.CON.KSGX.FF.W.0024.000000T0000Z-120817T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-SAN BERNARDINO CA-
143 PM PDT FRI AUG 17 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 PM PDT FOR
SOUTHWESTERN SAN BERNARDINO AND NORTHWESTERN RIVERSIDE COUNTIES...

AT 137 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE HEAVY RAIN PRODUCING FLASH FLOODING OVER THE WARNED AREA.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO FOREST 
FALLS...OAK GROVE...AND EASTERN PORTIONS OF YUCAIPA AND CALIMESA.

LAT...LON 3410 11701 3411 11683 3396 11688 3397 11708

$$

MM
295 
WGUS76 KSGX 172100
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
200 PM PDT FRI AUG 17 2012

CAC065-071-172130-
/O.CON.KSGX.FF.W.0024.000000T0000Z-120817T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-SAN BERNARDINO CA-
200 PM PDT FRI AUG 17 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 PM PDT FOR
SOUTHWESTERN SAN BERNARDINO AND NORTHWESTERN RIVERSIDE COUNTIES...

AT 150 PM PDT...TRAINED WEATHER SPOTTERS REPORTED HEAVY RAIN 
PRODUCING FLASH FLOODING OVER THE WARNED AREA IN THE MILL CREEK 
DRAINAGE. TRAVEL ON VALLEY OF THE FALLS DRIVE IS NOT POSSIBLE. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO FOREST 
FALLS...OAK GLEN...YUCAIPA AND CALIMESA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLOOD WATERS ARE MOVING DOWN MILL CREEK.
 
DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
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 ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

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

&&

LAT...LON 3410 11701 3411 11683 3396 11688 3397 11708

$$

MM
009 
WGUS56 KSGX 172126
FFWSGX
CAC065-071-172330-
/O.EXT.KSGX.FF.W.0024.000000T0000Z-120817T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
226 PM PDT FRI AUG 17 2012

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  NORTHWESTERN RIVERSIDE COUNTY IN SOUTHERN CALIFORNIA...
  SOUTHWESTERN SAN BERNARDINO COUNTY IN SOUTHERN CALIFORNIA...
  THIS INCLUDES THE CITY OF YUCAIPA...

* UNTIL 430 PM PDT.

* AT 218 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR 
  CONTINUES TO INDICATE HEAVY RAINFALL OVER THE FOREST FALLS
  AND YUCAIPA AND SURROUNDING AREAS. ALSO...A TRAINED WEATHER 
  SPOTTER REPORTED FLOODING OF MILL CREEK WITH BOULDERS AND 
  DEBRIS FLOWING ACROSS THE VALLEY OF THE FALLS.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO FOREST
  FALLS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
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 ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 3410 11701 3411 11683 3396 11688 3397 11708

$$

HARRISON
392 
WGUS76 KSGX 172225
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
325 PM PDT FRI AUG 17 2012

CAC065-071-172330-
/O.CON.KSGX.FF.W.0024.000000T0000Z-120817T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-SAN BERNARDINO CA-
325 PM PDT FRI AUG 17 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM PDT FOR
SOUTHWESTERN SAN BERNARDINO AND NORTHWESTERN RIVERSIDE COUNTIES...

AT 315 PM PDT...TRAINED WEATHER SPOTTERS REPORTED HEAVY RAIN 
PRODUCING FLASH FLOODING OVER THE WARNED AREA AND A MUD SLIDE EAST 
OF FOREST FALLS.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO FOREST 
FALLS...OAK GLEN AND YUCAIPA

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DEBRIS FLOWS...INCLUDING MUD AND ROCK SLIDES...ARE EXPECTED WITH THIS
STORM. MUD SLIDES AND ROCK SLIDES CAN POTENTIALLY TRAP AND KILL
PEOPLE CAUGHT IN THEIR PATH.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
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 ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 3410 11701 3411 11683 3396 11688 3397 11708

$$

MM
905 
WGUS76 KSGX 172328
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
428 PM PDT FRI AUG 17 2012

CAC065-071-172336-
/O.EXP.KSGX.FF.W.0024.000000T0000Z-120817T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-SAN BERNARDINO CA-
428 PM PDT FRI AUG 17 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 430 PM PDT FOR SOUTHWESTERN
SAN BERNARDINO AND NORTHWESTERN RIVERSIDE COUNTIES...

RAIN HAS BEEN DECREASING OVER THE PAST TWO HOURS OVER THE FOREST 
FALLS AREA. MILL CREEK AND OTHER TRIBUTARY CREEKS MAY STILL BE 
RUNNING FULL THE REST OF THE AFTERNOON...BUT WILL RAPIDLY RECEDE.

LAT...LON 3410 11701 3411 11683 3396 11688 3397 11708

$$

MM

The office that day

Everything else NWS San Diego, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 16, 7:07 PM PDTFlash Flood WatchSGXRiverside, San Bernardino, San Diego25 hr
Aug 17, 12:14 PM PDTFlash Flood WarningSGXRiverside61 min
Aug 17, 12:28 PM PDTFlash Flood WarningSGXRiverside, San Diego2 hr
Aug 17, 12:55 PM PDTSevere Thunderstorm WarningSGXRiverside50 min
Aug 17, 1:39 PM PDTSevere Thunderstorm WarningSGXSan Diego51 min
Aug 17, 1:40 PM PDTFlash Flood WarningSGXSan Diego95 min
Aug 17, 2:19 PM PDTFlash Flood WarningSGXRiverside46 min
Aug 17, 3:19 PM PDTAreal Flood AdvisorySGXSan Bernardino86 min
Aug 17, 4:47 PM PDTAreal Flood AdvisorySGXSan Bernardino75 min

Nearby

Flash Flood Warnings in California, 2012Every flash flood warning in 2012

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.