Alert archive / California / Flash Flood Warnings in 2011

Flash Flood Warning 7, NWS Phoenix, AZ

September 13, 2011Riverside County, California

NWS Phoenix, AZ issued this flash flood warning at Sep 13, 2011, 3:00 PM PDT for Riverside County, California. It was in force for 106 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Sep 13, 2011, 3:00 PM PDT (22:00 UTC)
Expired: Sep 13, 2011, 4:46 PM PDT
In force: 106 min
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Flood severity: None

County Riverside County, CA

The radar

The Yuma radar (KYUX), 154 km from the middle of the area, began a volume at 22:00 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

Yuma Intl Airpor, AZ (KYUM), launched 12:00Z, 10.0 hours before the alert went out and 139 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: 555 J/kg
Mixed-layer CIN: -307 J/kg
Mixed-layer LCL: 1873 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 87 m²/s²
0-3 km storm-relative helicity: 161 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

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

072 
WGUS55 KPSR 132200
FFWPSR
CAC065-140200-
/O.NEW.KPSR.FF.W.0007.110913T2200Z-110914T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
300 PM PDT TUE SEP 13 2011

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EASTERN RIVERSIDE COUNTY IN SOUTHERN CALIFORNIA...
  THIS INCLUDES THE CITIES OF...DESERT CENTER...CHIRIACO SUMMIT...

* UNTIL 700 PM PDT

* AT 251 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUES 
TO SHOW PERSISTENT SHOWERS AND THUNDERSTORMS ACROSS EASTERN 
RIVERSIDE COUNTY. RAINFALL AMOUNTS IN EXCESS OF THREE INCHES HAVE 
BEEN REPORTED IN CHIRIACO SUMMIT AND SOME SPOTS MAY SEE AN 
ADDITIONAL ONE TO TWO INCHES OF RAIN. RUNNING WATER MAY BE COVERING 
ROADWAYS AND DANGEROUS FLOODING IS POSSIBLE.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO MIDLAND AND
  EAGLE MTN

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 FLASH FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR
VEHICLE INTO AREAS WHERE RUNNING WATER COVERS THE ROADWAY. JUST ONE
FOOT OF FLOWING WATER CAN BE POWERFUL ENOUGH TO SWEEP VEHICLES OFF
THE ROAD. MAKE THE SMART CHOICE TURN AROUND DONT DROWN.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE.

&&

LAT...LON 3407 11455 3400 11450 3387 11465 3376 11488
      3356 11494 3345 11550 3343 11593 3373 11582
      3397 11526 3381 11517 3378 11508 3396 11503
      3406 11492 3409 11483

$$

HIRSCH

2 follow-up statements

451 
WGUS75 KPSR 132307
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
407 PM PDT TUE SEP 13 2011

CAC065-140200-
/O.CON.KPSR.FF.W.0007.000000T0000Z-110914T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-
407 PM PDT TUE SEP 13 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 700 PM PDT FOR
EASTERN RIVERSIDE COUNTY...

AT 353 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUES TO 
SHOW PERSISTENT SHOWERS AND THUNDERSTORMS ACROSS EASTERN RIVERSIDE 
COUNTY. RAINFALL AMOUNTS IN EXCESS OF THREE INCHES HAVE BEEN 
REPORTED IN CHIRIACO SUMMIT...AND SOME AREAS MAY SEE AN ADDITIONAL 
INCH OF RAIN. RUNNING WATER MAY BE COVERING ROADWAYS AND DANGEROUS 
FLOODING IS POSSIBLE.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO 
MIDLAND...AND EAGLE MOUNTAIN.

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.

WHEN ENCOUNTERING FLOODED ROADS MAKE THE SMART CHOICE...TURN 
AROUND...DONT DROWN.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN
PHOENIX.

&&

LAT...LON 3407 11455 3400 11450 3387 11465 3376 11488
      3356 11494 3345 11550 3343 11593 3373 11582
      3397 11526 3381 11517 3378 11508 3396 11503
      3406 11492 3409 11483

$$

MEYERS

254 
WGUS75 KPSR 132346
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
446 PM PDT TUE SEP 13 2011

CAC065-132346-
/O.CAN.KPSR.FF.W.0007.000000T0000Z-110914T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-
446 PM PDT TUE SEP 13 2011

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR EASTERN RIVERSIDE
COUNTY...

SHOWERS AND THUNDERSTORM ACTIVITY CONTINUES TO DIMINISH...WITH JUST 
ISOLATED STORMS PERSISTING OVER THE AREA AND SLOWLY MOVING OFF TO 
THE NORTHEAST. EVEN THOUGH THE WARNING IS CANCELLED...RUNOFF WILL 
CONTINUE TO COLLECT AND FLOW IN WASHES AND LOW LYING AREAS OVER THE 
NEXT SEVERAL HOURS.

MOTORISTS SHOULD USE CAUTION AS LOCAL HIGHWAYS AND ROADWAYS MAY HAVE 
AREAS THAT ARE IMPASSABLE DUE TO WATER OR FLOOD DEBRIS.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY 
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE.

LAT...LON 3407 11455 3400 11450 3387 11465 3376 11488
      3356 11494 3345 11550 3343 11593 3373 11582
      3397 11526 3381 11517 3378 11508 3396 11503
      3406 11492 3409 11483

$$

MEYERS

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 13, 3:54 AM PDT	Flash Flood Watch	PSR		17 hr
Sep 13, 7:05 AM PDT	Severe Thunderstorm Warning	PSR	Riverside, San Bernardino	55 min
Sep 13, 7:10 AM PDT	Flash Flood Warning	PSR	Riverside	110 min
Sep 13, 7:55 AM PDT	Severe Thunderstorm Warning	PSR	Riverside, San Bernardino	55 min
Sep 13, 9:18 AM PDT	Areal Flood Advisory	PSR	Riverside	3 hr
Sep 13, 9:38 AM PDT	Severe Thunderstorm Warning	PSR	Riverside	33 min
Sep 13, 10:00 AM PDT	Severe Thunderstorm Warning	PSR	Imperial, Riverside	60 min
Sep 13, 10:53 AM PDT	Severe Thunderstorm Warning	PSR	Riverside, San Bernardino	40 min
Sep 13, 12:00 PM PDT	Flash Flood Warning	PSR	Riverside, San Bernardino	3 hr
Sep 13, 1:20 PM PDT	Dust Storm Warning	PSR		100 min
Sep 13, 1:21 PM PDT	Severe Thunderstorm Warning	PSR	Imperial	54 min
Sep 13, 2:12 PM PDT	Severe Thunderstorm Warning	PSR	Imperial	63 min
Sep 13, 3:15 PM PDT	Special Weather Statement	PSR	Imperial	45 min
Sep 13, 4:54 PM PDT	Special Weather Statement	PSR	Imperial	21 min

Nearby

Flash Flood Warnings in California, 2011 Every 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.