Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 32, NWS San Diego, CA

August 30, 2012San Diego County, California

NWS San Diego, CA issued this flash flood warning at Aug 30, 2012, 12:11 PM PDT for San Diego 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, 12:11 PM PDT (19:11 UTC)
Expired: Aug 30, 2012, 3:15 PM PDT
In force: 3 hr
Issued by: NWS San Diego, CA
Area: Storm-based polygon
Flood severity: None

County San Diego County, CA

The radar

The San Diego radar (KNKX), 72 km from the middle of the area, began a volume at 19:11 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.

What was reported inside it

Time	Report	Where	Remark
Aug 30, 3:01 PM PDT	FLASH FLOOD	7 Nw Agua Caliente Spri, CA	HEAVY RAIN RESULTED IN DEBRIS FLOW ON HIGHWAY 78 NEAR SHELTER VALLEY AND LIZARD CREEK. A 2 FOOT BOULDER HAD TO BE REMOVED FROM THE ROADWAY AND ONE LANE OF THE HIGHWAY WAS CLOSED. PICTURES TO COME.

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

The nearest sounding before it

San Diego, CA (KNKX), launched 12:00Z, 7.2 hours before the alert went out and 89 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2209 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 73 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.

108 
WGUS56 KSGX 301911
FFWSGX
CAC073-302215-
/O.NEW.KSGX.FF.W.0032.120830T1911Z-120830T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
1211 PM PDT THU AUG 30 2012

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL SAN DIEGO COUNTY IN SOUTHWEST CALIFORNIA...

* UNTIL 315 PM PDT

* AT 1206 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED  
  A STORM CAPABLE OF PRODUCING FLASH FLOODING OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO OCOTILLO   
  WELLS...SHELTER VALLEY...AND CANEBRAKE.

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.

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 3278 11611 3287 11631 3299 11642 3314 11653
      3323 11641 3320 11608

$$

SS

2 follow-up statements

045 
WGUS76 KSGX 302021
FFSSGX

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

CAC073-302215-
/O.CON.KSGX.FF.W.0032.000000T0000Z-120830T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-
121 PM PDT THU AUG 30 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 315 PM PDT FOR EAST
CENTRAL SAN DIEGO COUNTY...

AT 112 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE HEAVY RAIN CAPABLE OF PRODUCING FLASH FLOODING OVER THE 
WARNED AREA.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO OCOTILLO 
WELLS AND SHELTER VALLEY.

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 3278 11611 3287 11631 3299 11642 3314 11653
      3323 11641 3320 11608

$$

SS

862 
WGUS76 KSGX 302211
FFSSGX

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

CAC073-302221-
/O.EXP.KSGX.FF.W.0032.000000T0000Z-120830T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-
311 PM PDT THU AUG 30 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 315 PM PDT FOR EAST CENTRAL
SAN DIEGO COUNTY...

LIGHT RAINFALL CONTINUES OVER THE AREA AND MINOR ADDITIONAL RUNOFF 
MAY OCCUR OVER THE NEXT TWO HOURS. HOWEVER...THE FLASH FLOOD THREAT 
HAS ENDED AND THE FLASH FLOOD WARNING WILL BE ALLOWED TO EXPIRE AT 
315 PM.

LAT...LON 3278 11611 3287 11631 3299 11642 3314 11653
      3323 11641 3320 11608

$$

SS

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 29, 8:47 PM PDT	High Surf Advisory	SGX	San Diego	4 days
Aug 30, 3:18 AM PDT	Flash Flood Watch	SGX	Riverside, San Bernardino, San Diego	16 hr
Aug 30, 11:57 AM PDT	Flash Flood Warning	SGX	Riverside, San Bernardino	2 hr
Aug 30, 12:04 PM PDT	Areal Flood Advisory	SGX	San Diego	116 min
Aug 30, 12:11 PM PDT	Severe Thunderstorm Warning	SGX	San Diego	34 min
Aug 30, 12:18 PM PDT	Severe Thunderstorm Warning	SGX	San Diego	57 min
Aug 30, 12:45 PM PDT	Flash Flood Warning	SGX	Riverside	3 hr
Aug 30, 12:50 PM PDT	Special Weather Statement	SGX	San Diego	55 min
Aug 30, 1:05 PM PDT	Flash Flood Warning	SGX	San Bernardino	3 hr
Aug 30, 1:30 PM PDT	Areal Flood Advisory	SGX	Riverside, San Bernardino, San Diego	3 hr
Aug 30, 1:52 PM PDT	Severe Thunderstorm Warning	SGX	Riverside, San Bernardino	53 min
Aug 30, 1:58 PM PDT	Flash Flood Warning	SGX	San Bernardino	2 hr
Aug 30, 2:31 PM PDT	Flash Flood Warning	SGX	Riverside	119 min
Aug 30, 2:38 PM PDT	Areal Flood Advisory	SGX	San Bernardino	40 min
Aug 30, 2:45 PM PDT	Severe Thunderstorm Warning	SGX	Riverside	60 min
Aug 30, 3:10 PM PDT	Flash Flood Warning	SGX	San Bernardino	2 hr

Nearby

Flash Flood Warnings in California, 2012 Every 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.