Alert archive / Arizona / Flash Flood Warnings in 2012

Flash Flood Warning 53, NWS Phoenix, AZ

August 22, 2012La Paz County, Arizona; Riverside County, California

NWS Phoenix, AZ issued this flash flood warning at Aug 22, 2012, 6:42 PM MST for La Paz County, Arizona; Riverside County, California. It was in force for 70 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: Aug 22, 2012, 6:42 PM MST (01:42 UTC)
Expired: Aug 22, 2012, 7:52 PM MST
In force: 70 min
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Flood severity: None

Counties La Paz County, AZ, Riverside County, CA

The radar

The Yuma radar (KYUX), 124 km from the middle of the area, began a volume at 01:42 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 00:00Z, 1.7 hours before the alert went out and 106 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: 950 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 2077 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 39 m²/s²
0-3 km storm-relative helicity: 57 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

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

523 
WGUS55 KPSR 230142
FFWPSR
AZC012-CAC065-230345-
/O.NEW.KPSR.FF.W.0053.120823T0142Z-120823T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
642 PM MST WED AUG 22 2012

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL RIVERSIDE COUNTY IN SOUTHERN CALIFORNIA...
  WEST CENTRAL LA PAZ COUNTY IN WEST CENTRAL ARIZONA...

* UNTIL 845 PM MST/845 PM PDT/

* AT 637 PM MST...VERY HEAVY RAIN THAT WILL CAUSE FLASH FLOODING WAS 
REPORTED IN THE CITY OF BLYTHE. UP TO AN INCH OF RAIN HAS FALLEN SO 
FAR AND AN ADDITIONAL INCH IS POSSIBLE THROUGH 8 PM.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO BLYTHE

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF NORMALLY
DRY WASHES AND CREEKS...STREETS AND UNDERPASSES...AND DETENTION
BASINS AFFECTING SOME COMMUNITY PARKS. UNBRIDGED CROSSINGS WILL BE
ESPECIALLY DANGEROUS.

TO REPORT FLOODING...PLEASE RELAY YOUR REPORT TO LOCAL LAW
ENFORCEMENT WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 3360 11464 3371 11463 3371 11440 3351 11448
      3350 11458 3360 11458

$$

HIRSCH

1 follow-up statement

696 
WGUS75 KPSR 230252
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
752 PM MST WED AUG 22 2012

AZC012-CAC065-230257-
/O.CAN.KPSR.FF.W.0053.000000T0000Z-120823T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LA PAZ AZ-RIVERSIDE CA-
752 PM MST WED AUG 22 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR EAST CENTRAL
RIVERSIDE AND WEST CENTRAL LA PAZ COUNTIES...

HEAVY RAIN HAS MOVED EAST OF BLYTHE AND FLASH FLOODING IS NO LONGER 
ANTICIPATED. HOWEVER...ISOLATED SHOWERS MAY STILL PRODUCE BRIEF 
PERIODS OF MODERATE TO HEAVY RAIN THROUGH MIDNIGHT. PONDING OF WATER 
ON ROADWAYS AND MINOR FLOODING OF NEARBY CREEKS AND WASHES WILL 
REMAIN A THREAT THIS EVENING.

LAT...LON 3360 11464 3371 11463 3371 11440 3351 11448
      3350 11458 3360 11458

$$

HIRSCH

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 22, 5:47 PM MST	Flash Flood Warning	PSR	La Paz	3 hr
Aug 22, 6:21 PM MST	Areal Flood Advisory	PSR	La Paz	114 min
Aug 22, 6:44 PM MST	Special Weather Statement	PSR		46 min
Aug 22, 7:16 PM MST	Special Weather Statement	PSR		44 min
Aug 22, 8:53 PM MST	Areal Flood Advisory	PSR	La Paz, Yuma	112 min
Aug 22, 9:08 PM MST	Areal Flood Advisory	PSR	La Paz	112 min
Aug 22, 11:01 PM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Aug 23, 1:05 AM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Aug 23, 1:46 AM MST	Areal Flood Advisory	PSR	Maricopa	119 min
Aug 23, 2:03 AM MST	Special Weather Statement	PSR		27 min
Aug 23, 2:08 AM MST	Special Weather Statement	PSR		37 min
Aug 23, 2:22 AM MST	Areal Flood Advisory	PSR	Maricopa	113 min
Aug 23, 5:29 AM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Aug 23, 9:37 AM MST	River Flood Advisory	PSR	Yuma	5 hr

Nearby

Flash Flood Warnings in Arizona, 2012 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.