Alert archive / Arizona / Flash Flood Warnings in 2012

Flash Flood Warning 40, NWS Tucson, AZ

August 21, 2012Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 21, 2012, 2:49 PM MST for Pima County, Arizona. It was in force for 86 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 21, 2012, 2:49 PM MST (21:49 UTC)
Expired
Aug 21, 2012, 4:15 PM MST
In force
86 min
Issued by
NWS Tucson, AZ
Area
Storm-based polygon
Flood severity
None

County Pima County, AZ

The radar

The Tucson radar (KEMX), 51 km from the middle of the area, began a volume at 21:50 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

Tuscon, AZ (KDMA), launched 12:00Z, 9.8 hours before the alert went out and 24 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 2012-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1386 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 2012-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 square meters per square second.1939Sfc1 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
1386 J/kg
Mixed-layer CIN
-110 J/kg
Mixed-layer LCL
1261 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
32 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.

191 
WGUS55 KTWC 212149
FFWTWC
AZC019-212315-
/O.NEW.KTWC.FF.W.0040.120821T2149Z-120821T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
249 PM MST TUE AUG 21 2012

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN PIMA COUNTY IN SOUTH CENTRAL ARIZONA...

* UNTIL 415 PM MST

* AT 236 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  A THUNDERSTORM WITH HEAVY RAIN NEAR SABINO CANYON...MOVING  
  SOUTHWEST AT 5 MPH. DOPPLER RADAR INDICATED THAT UP TO ONE INCH OF 
  RAIN HAS FALLEN IN PORTIONS OF THE SABINO CANYON AREA.

* THE STORM PRODUCING FLASH FLOODING WILL OTHERWISE REMAIN NEAR THE 
  CATALINA FOOTHILLS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF WASHES 
AND STREAMS AND ROADS.

&&

LAT...LON 3229 11075 3236 11083 3242 11074 3236 11066

$$
2 follow-up statements
470 
WGUS75 KTWC 212232
FFSTWC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
332 PM MST TUE AUG 21 2012

AZC019-212315-
/O.CON.KTWC.FF.W.0040.000000T0000Z-120821T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PIMA AZ-
332 PM MST TUE AUG 21 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 415 PM MST FOR
NORTHEASTERN PIMA COUNTY...

AT 325 PM MST...SHOWERS WERE WEAKENING NEAR SABINO CANYON. EARLIER 
VERY HEAVY RAINFALL BETWEEN 1 AND 2 INCHES NEAR AND NORTH OF SABINO 
CANYON WILL CONTINUE HEAVY RUNOFF IN THE AREA THIS AFTERNOON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS INCLUDES THE FOLLOWING STREAMS AND DRAINAGES...
SABINO CREEK...BIRD CANYON AND AGUA CALIENTE WASH.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOW
LYING AREAS ARE SUBJECT TO FLOODING.

&&

LAT...LON 3229 11075 3236 11083 3242 11074 3236 11066

$$

MEYER
914 
WGUS75 KTWC 212316
FFSTWC

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
416 PM MST TUE AUG 21 2012

AZC019-212325-
/O.EXP.KTWC.FF.W.0040.000000T0000Z-120821T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
PIMA AZ-
416 PM MST TUE AUG 21 2012

...THE FLASH FLOOD WARNING HAS EXPIRED FOR NORTHEASTERN PIMA
COUNTY...

HEAVY FLOW IS STILL POSSIBLE INTO THE EARLY EVENING HOURS IN SABINO 
CANYON. ELSEWHERE STRONG TO SEVERE THUNDERSTORMS CONTINUED TO 
GENERATE LOCALLY HEAVY RAINFALL OVER OTHER AREAS OF EASTERN PIMA 
COUNTY.

LAT...LON 3229 11075 3236 11083 3242 11074 3236 11066

$$

MEYER

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 5:59 PM MSTFlash Flood WarningTWCPima2 hr
Aug 20, 6:10 PM MSTAreal Flood AdvisoryTWCPima80 min
Aug 20, 7:26 PM MSTAreal Flood AdvisoryTWCPima109 min
Aug 20, 7:40 PM MSTSpecial Weather StatementTWCPima50 min
Aug 21, 12:17 PM MSTSevere Thunderstorm WarningTWCGraham28 min
Aug 21, 1:04 PM MSTSevere Thunderstorm WarningTWCPinal26 min
Aug 21, 2:10 PM MSTSpecial Weather StatementTWCCochise50 min
Aug 21, 3:12 PM MSTSpecial Weather StatementTWC48 min
Aug 21, 3:28 PM MSTSevere Thunderstorm WarningTWCCochise, Pima47 min
Aug 21, 3:34 PM MSTSevere Thunderstorm WarningTWCPima41 min
Aug 21, 3:53 PM MSTAreal Flood AdvisoryTWCPima112 min
Aug 21, 4:15 PM MSTSevere Thunderstorm WarningTWCPima45 min
Aug 21, 4:34 PM MSTAreal Flood AdvisoryTWCPima116 min
Aug 21, 4:42 PM MSTAreal Flood AdvisoryTWCPima, Santa Cruz2 hr

Nearby

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