Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 60, NWS Phoenix, AZ

September 3, 2012Riverside County, California

NWS Phoenix, AZ issued this flash flood warning at Sep 3, 2012, 4:23 PM PDT for Riverside County, California. It was in force for 112 min. 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
Sep 3, 2012, 4:23 PM PDT (23:23 UTC)
Expired
Sep 3, 2012, 6:15 PM PDT
In force
112 min
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Flood severity
None

County Riverside County, CA

The radar

The Yuma radar (KYUX), 159 km from the middle of the area, began a volume at 23:24 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
Sep 3, 4:36 PM PDTFLASH FLOOD5 Ne Desert Center, CACHP REPORTS ROADWAY FLOODING PROMPTING CLOSURE OF SR 177 NE OF DESERT CENTER.

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, 11.4 hours before the alert went out and 209 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, San Diego, CA at 12:00Z on 2012-09-03Temperature 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, San Diego, CA at 12:00Z on 2012-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 square meters per square second.193958Sfc1 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
3323 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
46 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.

780 
WGUS55 KPSR 032323
FFWPSR
CAC065-040115-
/O.NEW.KPSR.FF.W.0060.120903T2323Z-120904T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
423 PM PDT MON SEP 3 2012

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL RIVERSIDE COUNTY IN SOUTHERN CALIFORNIA...

* UNTIL 615 PM PDT

* AT 414 PM PDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED
  VERY HEAVY RAIN THAT WILL CAUSE FLASH FLOODING.

* THE STORM PRODUCING VERY HEAVY RAIN THAT WILL CAUSE FLASH 
  FLOODING HAS BEEN NEARLY STATIONARY OVER DESERT CENTER RICE
  ROAD FOR THE LAST HOUR. RADAR ESTIMATES THAT ONE HALF TO NEAR 
  TWO INCHES OF RAIN HAS FALLEN OVER THE AREA HEAVY RAINFALL 
  WILL CONTINUE AS THE STORM SLOWLY MOVES ACROSS THE ROADWAY...
  APPROXIMATELY 10 TO 12 MILES NORTHEAST OF DESERT CENTER. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT PEOPLE ALONG THE BANKS OF WASHES AND
CREEKS SHOULD MOVE TO HIGHER GROUND IMMEDIATELY. NORMALLY DRY WASHES
AND STREAMS WILL SUDDENLY HAVE RUNNING WATER AND MAKE UNBRIDGED
CROSSINGS IMPASSABLE. STREETS...UNDERPASSES...AND LOW SPOTS WILL
BECOME INUNDATED MAKING DRIVING HAZARDOUS IN THE WARNED AREA.

MOST FLOOD DEATHS OCCUR IN MOTORIZED VEHICLES. WHEN ENCOUNTERING
FLOODED ROADS...MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

&&

LAT...LON 3384 11536 3386 11523 3378 11524 3376 11534

$$

NOLTE
2 follow-up statements
241 
WGUS75 KPSR 032346
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
446 PM PDT MON SEP 3 2012

CAC065-040115-
/O.CON.KPSR.FF.W.0060.000000T0000Z-120904T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-
446 PM PDT MON SEP 3 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM PDT FOR
CENTRAL RIVERSIDE COUNTY...

AT 438 PM PDT...HIGHWAY PATROL HAS REPORTED ROADWAY FLOODING ALONG 
DESERT CENTER RICE ROAD OR STATE ROUTE 177 NORTH OF DESERT CENTER. A 
THUNDERSTORM PRODUCING VERY HEAVY RAIN THAT HAS CAUSED FLASH 
FLOODING IS SLOWING MOVING SOUTH OF THE AREA. WHILE THE RAINFALL 
MIGHT HAVE DISSIPATED OR ENDED ACROSS THE AREA...CONCERNS FOR FLASH 
FLOOD STILL CONTINUE AS RUNOFF WILL MOVE THROUGH THE 
AREA...IMPACTING ROADWAYS...ESPECIALLY THOSE WITH LOW WATER 
CROSSINGS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLOOD DEATHS OCCUR IN MOTORIZED VEHICLES. WHEN ENCOUNTERING
FLOODED ROADS...MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF NORMALLY
DRY WASHES AND CREEKS...ROADS...AND LOW LYING SPOTS. UNBRIDGED
CROSSINGS WILL BE ESPECIALLY DANGEROUS.

&&

LAT...LON 3384 11536 3386 11523 3378 11524 3376 11534

$$

NOLTE
620 
WGUS75 KPSR 040108 RRA
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
608 PM PDT MON SEP 3 2012

CAC065-040116-
/O.EXP.KPSR.FF.W.0060.000000T0000Z-120904T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-
608 PM PDT MON SEP 3 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 615 PM PDT FOR CENTRAL
RIVERSIDE COUNTY...

THE ISOLATED THUNDERSTORM THAT PRODUCED HEAVY RAINFALL AND ROADWAY 
FLOODING NORTH OF DESERT CENTER HAS SINCE DISSIPATED. AS SUCH...THE 
FLASH FLOOD WARNING WILL BE ALLOWED TO EXPIRE.

ROADWAY FLOODING AND RUNNING OF NORMALLY DRY WASHES WILL CONTINUE 
FOR THE NEXT FEW HOURS. DO NOT DRIVE AROUND ROAD BARRICADES OR WATER 
COVERED ROADWAYS. MAKE THE SMART CHOICE...TURN AROUND DONT DROWN.

LAT...LON 3384 11536 3386 11523 3378 11524 3376 11534

$$

NOLTE

The office that day

Everything else NWS Phoenix, AZ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 3, 3:52 PM PDTAreal Flood AdvisoryPSRRiverside79 min
Sep 3, 4:23 PM PDTBlowing Dust AdvisoryPSR97 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.