Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 34, NWS San Diego, CA

August 30, 2012San Bernardino County, California

NWS San Diego, CA issued this flash flood warning at Aug 30, 2012, 1:05 PM PDT for 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 30, 2012, 1:05 PM PDT (20:05 UTC)
Expired
Aug 30, 2012, 4:00 PM PDT
In force
3 hr
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

County San Bernardino County, CA

What was reported inside it

TimeReportWhereRemark
Aug 30, 2:40 PM PDTFLOODLucerne Valley, CADRIVING INTO LUCERNE VALLEY FROM BARSTOW, SPOTTER SBD342 REPORTED STRONG WINDS AND PLENTY OF LIGHTNING. 1 TO 2 INCHES OF STANDING WATER ALONG HIGHWAY 47 ON THE NORTH SIDE OF TOWN.

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 92 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 2012-08-30Temperature 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 2012-08-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -36 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
2894 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
-36 m²/s²
0-3 km storm-relative helicity
16 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.

767 
WGUS56 KSGX 302005
FFWSGX
CAC071-302300-
/O.NEW.KSGX.FF.W.0034.120830T2005Z-120830T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
105 PM PDT THU AUG 30 2012

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL SAN BERNARDINO COUNTY IN SOUTHERN CALIFORNIA...

* UNTIL 400 PM PDT

* AT 1254 PM PDT...THUNDERSTORMS WITH VERY HEAVY RAINS COVERED AREAS 
  FROM THE NORTH SLOPES OF THE SAN BERNARDINO MOUNTAINS NORTH
  THROUGH LUCERNE VALLEY AND INTO THE HIGH DESERTS. RAIN RATES ARE
  EXCEEDING ONE INCH PER HOUR IN SOME AREAS.

* THE STORM PRODUCING FLASH FLOODING WILL OTHERWISE REMAIN OVER
  MAINLY RURAL AREAS OF THE INDICATED COUNTY.

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.

&&

LAT...LON 3471 11705 3470 11662 3425 11668 3429 11707

$$

MAXWELL
3 follow-up statements
559 
WGUS76 KSGX 302043
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
143 PM PDT THU AUG 30 2012

CAC071-302300-
/O.CON.KSGX.FF.W.0034.000000T0000Z-120830T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
143 PM PDT THU AUG 30 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 400 PM PDT FOR
CENTRAL SAN BERNARDINO COUNTY...

AT 136 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR SHOWED VERY 
HEAVY RAIN ALONG HIGHWAY 247 BETWEEN LUCERNE VALLEY AND BARSTOW. THE 
HEAVY RAIN WAS MOVING SLOWLY NORTHWEST AND WILL LIKELY PRODUCE FLASH 
FLOODING ALONG PARTS OF HIGHWAY 247 NORTH OF LUCERNE VALLEY.

RAINFALL HAD BECOME LESS HEAVY ALONG HIGHWAY 247 SOUTH OF LUCERNE 
VALLEY...BUT RUNOFF FROM PREVIOUS HEAVY RAIN WILL CONTINUE THROUGH 
230 PM...AND WATER COULD COVER SOME ROADWAYS IN THIS AREA.

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.

&&

LAT...LON 3471 11705 3470 11662 3425 11668 3429 11707

$$

MAXWELL
630 
WGUS76 KSGX 302201
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
301 PM PDT THU AUG 30 2012

CAC071-302300-
/O.CON.KSGX.FF.W.0034.000000T0000Z-120830T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
301 PM PDT THU AUG 30 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 400 PM PDT FOR
CENTRAL SAN BERNARDINO COUNTY...

AT 254 PM PDT...DOPPLER RADAR INDICATES THE STORMS OVER LUCERNE 
VALLEY HAVE WEAKENED SIGNIFICANTLY. HOWEVER...ADDITIONAL RUNOFF FROM 
LIGHT TO MODERATE RAIN WILL CONTINUE THE THREAT OF FLASH FLOODING.

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.

IN HILLY TERRAIN THERE ARE HUNDREDS OF LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS
FLOODED ROADS. FIND ALTERNATE ROUTES. IT TAKES ONLY A FEW INCHES OF
SWIFTLY FLOWING WATER TO CARRY VEHICLES AWAY.

&&

LAT...LON 3471 11705 3470 11662 3425 11668 3429 11707

$$

SS
937 
WGUS76 KSGX 302255
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
355 PM PDT THU AUG 30 2012

CAC071-302305-
/O.EXP.KSGX.FF.W.0034.000000T0000Z-120830T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
355 PM PDT THU AUG 30 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 400 PM PDT FOR CENTRAL SAN
BERNARDINO COUNTY...

LIGHT RAINFALL IN THE AREA MAY CAUSE ADDITIONAL MINOR 
RUNOFF...HOWEVER THE FLASH FLOOD THREAT HAS ENDED. THE FLASH FLOOD 
WARNING WILL BE ALLOWED TO EXPIRE AT 400 PM.

LAT...LON 3471 11705 3470 11662 3425 11668 3429 11707

$$

SS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 8:47 PM PDTHigh Surf AdvisorySGXSan Diego4 days
Aug 30, 3:18 AM PDTFlash Flood WatchSGXRiverside, San Bernardino, San Diego16 hr
Aug 30, 11:57 AM PDTFlash Flood WarningSGXRiverside, San Bernardino2 hr
Aug 30, 12:04 PM PDTAreal Flood AdvisorySGXSan Diego116 min
Aug 30, 12:11 PM PDTFlash Flood WarningSGXSan Diego3 hr
Aug 30, 12:11 PM PDTSevere Thunderstorm WarningSGXSan Diego34 min
Aug 30, 12:18 PM PDTSevere Thunderstorm WarningSGXSan Diego57 min
Aug 30, 12:45 PM PDTFlash Flood WarningSGXRiverside3 hr
Aug 30, 12:50 PM PDTSpecial Weather StatementSGXSan Diego55 min
Aug 30, 1:30 PM PDTAreal Flood AdvisorySGXRiverside, San Bernardino, San Diego3 hr
Aug 30, 1:52 PM PDTSevere Thunderstorm WarningSGXRiverside, San Bernardino53 min
Aug 30, 1:58 PM PDTFlash Flood WarningSGXSan Bernardino2 hr
Aug 30, 2:31 PM PDTFlash Flood WarningSGXRiverside119 min
Aug 30, 2:38 PM PDTAreal Flood AdvisorySGXSan Bernardino40 min
Aug 30, 2:45 PM PDTSevere Thunderstorm WarningSGXRiverside60 min
Aug 30, 3:10 PM PDTFlash Flood WarningSGXSan Bernardino2 hr

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.