Alert archive / Arizona / Flash Flood Warnings in 2011

Flash Flood Warning 52, NWS Tucson, AZ

August 20, 2011Santa Cruz County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 20, 2011, 2:59 PM MST for Santa Cruz County, Arizona. It was in force for 2 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 20, 2011, 2:59 PM MST (21:59 UTC)
Expired
Aug 20, 2011, 5:00 PM MST
In force
2 hr
Issued by
NWS Tucson, AZ
Area
Storm-based polygon
Flood severity
None

County Santa Cruz County, AZ

The radar

The Tucson radar (KEMX), 67 km from the middle of the area, began a volume at 22:01 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
Aug 20, 3:15 PM MSTFLASH FLOODNogales, AZUSGS GAUGE AT NOGALES WASH SHOWED 5 FOOT SPIKE

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

The nearest sounding before it

Tuscon, AZ (KTUS), launched 12:00Z, 10.0 hours before the alert went out and 91 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, Tuscon, AZ at 12:00Z on 2011-08-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 233 joules per kilogram.LCLLFCEL10008507005003002001001 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, Tuscon, AZ at 12:00Z on 2011-08-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 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
233 J/kg
Mixed-layer CIN
-69 J/kg
Mixed-layer LCL
1510 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
11 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.

672 
WGUS55 KTWC 202159
FFWTWC
AZC023-210000-
/O.NEW.KTWC.FF.W.0052.110820T2159Z-110821T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
259 PM MST SAT AUG 20 2011

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL SANTA CRUZ COUNTY IN SOUTHEAST ARIZONA...
  THIS INCLUDES THE CITY OF NOGALES...

* UNTIL 500 PM MST

* AT 247 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA. ONE TO TWO 
INCHES OF RAINFALL IN THE LAST HOUR HAS OCCURRED ACROSS NOGALES 
SONORA WITH FLASH FLOODING EXPECTED DOWNSTREAM ALONG THE NOGALES 
WASH INTO NOGALES ARIZONA. 

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF WASHES
AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES AS
WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

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 3133 11102 3141 11100 3142 11088 3133 11084
      3132 11101

$$

GL
2 follow-up statements
396 
WGUS75 KTWC 202259
FFSTWC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
359 PM MST SAT AUG 20 2011

AZC023-210000-
/O.CON.KTWC.FF.W.0052.000000T0000Z-110821T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SANTA CRUZ AZ-
359 PM MST SAT AUG 20 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 PM MST FOR SOUTH
CENTRAL SANTA CRUZ COUNTY...

AT 347 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED ONE 
TO TWO INCHES OF RAINFALL HAD OCCURRED ACROSS NOGALES SONORA. THIS 
HEAVY RAINFALL WILL LEAD TO CONTINUED FLASH FLOODING MAINLY IN THE 
NOGALES WASH AS IT FLOWS FROM NOGALES SONORA INTO NOGALES SONORA. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO NOGALES

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3133 11102 3141 11100 3142 11088 3133 11084
      3132 11101

$$

GL
313 
WGUS75 KTWC 202352
FFSTWC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
452 PM MST SAT AUG 20 2011

AZC023-210002-
/O.EXP.KTWC.FF.W.0052.000000T0000Z-110821T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SANTA CRUZ AZ-
452 PM MST SAT AUG 20 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 500 PM MST FOR SOUTH
CENTRAL SANTA CRUZ COUNTY...

FLOW IN THE NOGALES WASH AND OTHER WASHES IN THE NOGALES AREA WILL 
CONTINUE TO SUBSIDE INTO THE EARLY EVENING HOURS...THUS THE FLASH 
FLOOD WARNING WILL BE ALLOWED TO EXPIRE. 

LAT...LON 3133 11102 3141 11100 3142 11088 3133 11084
      3132 11101

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 19, 5:18 PM MSTSpecial Weather StatementTWCSanta Cruz27 min
Aug 19, 5:57 PM MSTSpecial Weather StatementTWCSanta Cruz33 min
Aug 19, 6:26 PM MSTAreal Flood AdvisoryTWCPima94 min
Aug 19, 7:58 PM MSTSpecial Weather StatementTWCCochise32 min
Aug 20, 12:00 PM MSTFlash Flood WarningTWCCochise90 min
Aug 20, 3:30 PM MSTSpecial Weather StatementTWCSanta Cruz30 min

Nearby

Flash Flood Warnings in Arizona, 2011Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.