Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 120, NWS Tucson, AZ

August 13, 2021Cochise County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 13, 2021, 2:42 PM MST for Cochise County, Arizona. It was in force for 3 hr. 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 13, 2021, 2:42 PM MST (21:42 UTC)
Expired
Aug 13, 2021, 5:45 PM MST
In force
3 hr
Issued by
NWS Tucson, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Cochise County, AZ

The radar

The Tucson radar (KEMX), 75 km from the middle of the area, began a volume at 21:42 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

Tuscon, AZ (KTUS), launched 12:00Z, 9.7 hours before the alert went out and 115 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 2021-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 544 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 2021-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -36 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
544 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
1049 m above ground
0-6 km bulk shear
1 kt
0-1 km storm-relative helicity
-36 m²/s²
0-3 km storm-relative helicity
-1 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

701 
WGUS55 KTWC 132142
FFWTWC
AZC003-140045-
/O.NEW.KTWC.FF.W.0120.210813T2142Z-210814T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
242 PM MST Fri Aug 13 2021

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  Southwestern Cochise County in southeastern Arizona...

* Until 545 PM MST.

* At 242 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2.5 inches of 
  rain have fallen. Additional rainfall amounts up to 1 inch are 
  possible in the warned area. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Eastern Portions of Sierra Vista, Hereford and Palominas.

This includes the following streams and drainages...
  San Pedro River and Spring Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Stay away or be swept away. River banks and culverts can become 
unstable and unsafe.

&&

LAT...LON 3133 11012 3136 11012 3147 11015 3157 11019
      3162 11003 3154 11001 3146 10997 3139 10996
      3133 10996 3133 11000

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

JRM
1 follow-up statement
147 
WGUS75 KTWC 132231
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
331 PM MST Fri Aug 13 2021

AZC003-140045-
/O.CON.KTWC.FF.W.0120.000000T0000Z-210814T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cochise AZ-
331 PM MST Fri Aug 13 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM MST THIS 
AFTERNOON FOR SOUTHWESTERN COCHISE COUNTY...

At 331 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1 and 2.5 inches of rain have 
fallen. Additional rainfall amounts up to 1 inch are possible in the 
warned area. Flash flooding is already occurring on portions of 
Highway 92 around Palominas and Mile marker 339. Additional flash 
flooding is likely ongoing across the rest of the warned area.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Sierra Vista, Hereford and Palominas.

This includes the following streams and drainages...
  San Pedro River and Spring Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

Stay away or be swept away. River banks and culverts can become 
unstable and unsafe.

&&

LAT...LON 3133 11012 3136 11012 3147 11015 3157 11019
      3162 11003 3154 11001 3146 10997 3139 10996
      3133 10996 3133 11000

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

JRM

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 6:10 PM MSTAreal Flood AdvisoryTWCCochise3 hr
Aug 12, 6:42 PM MSTFlash Flood Warning Considerable damage threatTWCCochise2 hr
Aug 12, 11:08 PM MSTAreal Flood AdvisoryTWCSanta Cruz112 min
Aug 13, 1:56 PM MSTAreal Flood AdvisoryTWCCochise, Santa Cruz118 min
Aug 13, 2:04 PM MSTAreal Flood AdvisoryTWCSanta Cruz109 min
Aug 13, 2:25 PM MSTSpecial Weather StatementTWCGraham50 min
Aug 13, 3:14 PM MSTSpecial Weather StatementTWCGraham46 min
Aug 13, 3:20 PM MSTSpecial Weather StatementTWC40 min
Aug 13, 3:30 PM MSTSevere Thunderstorm WarningTWCGraham, Pinal45 min
Aug 13, 3:56 PM MSTFlash Flood Warning Considerable damage threatTWCCochise5 hr
Aug 13, 4:06 PM MSTSpecial Weather StatementTWCCochise39 min
Aug 13, 4:35 PM MSTSpecial Weather StatementTWCSanta Cruz25 min
Aug 13, 4:37 PM MSTAreal Flood AdvisoryTWCGraham, Greenlee113 min
Aug 13, 4:43 PM MSTSevere Thunderstorm WarningTWCSanta Cruz47 min

Nearby

Flash Flood Warnings in Arizona, 2021Every flash flood warning in 2021

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.