Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 96, NWS Tucson, AZ

August 8, 2021Cochise County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 8, 2021, 6:46 PM MST for Cochise County, Arizona. It was in force for 5 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 8, 2021, 6:46 PM MST (01:46 UTC)
Expired
Aug 8, 2021, 11:45 PM MST
In force
5 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), 46 km from the middle of the area, began a volume at 01:49 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 8, 8:13 PM MSTFLASH FLOOD1 N Saint David, AZDRAGOON WASH FLOWING OVER ROAD. BLOCKING VEHICLES FROM CROSSING.

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 00:00Z, 1.8 hours before the alert went out and 76 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 00:00Z on 2021-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 742 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 00:00Z on 2021-08-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -60 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
742 J/kg
Mixed-layer CIN
-62 J/kg
Mixed-layer LCL
2449 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-60 m²/s²
0-3 km storm-relative helicity
31 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

303 
WGUS55 KTWC 090146
FFWTWC
AZC003-090445-
/O.NEW.KTWC.FF.W.0096.210809T0146Z-210809T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
646 PM MST Sun Aug 8 2021

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  West Central Cochise County in southeastern Arizona...

* Until 945 PM MST.

* At 646 PM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  1 and 2 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 and automated gauges.

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

* Some locations that will experience flash flooding include...
  Benson, St. David and Kartchner Caverns State Park.

This includes the following Flash Flood Prone Locations...
	Sibyl Rd at Gila/Dragoon Wash.

This includes the following streams and drainages...
  Middle Canyon Wash, Dragoon Wash, Clifford Wash, San Pedro River, 
  Slavin Wash and Escalante Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3193 10997 3182 11003 3182 11017 3177 11036
      3187 11037 3196 11029 3202 11022 3203 11017
      3201 11014 3202 11009 3198 11001

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

$$

JRM
3 follow-up statements
061 
WGUS75 KTWC 090226
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
726 PM MST Sun Aug 8 2021

AZC003-090445-
/O.CON.KTWC.FF.W.0096.000000T0000Z-210809T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cochise AZ-
726 PM MST Sun Aug 8 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 PM MST THIS 
EVENING FOR WEST CENTRAL COCHISE COUNTY...

At 726 PM MST, Doppler radar and automated rain gauges indicated 
thunderstorms produced heavy rain across the warned area. Between 1 
and 2 inches of rain have fallen. Additional rainfall amounts up to 
0.25 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 and automated gauges.

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

Some locations that will experience flash flooding include...
  Benson, St. David and Kartchner Caverns State Park.

This includes the following Flash Flood Prone Locations...
	Sibyl Rd at Gila/Dragoon Wash.

This includes the following streams and drainages...
  Middle Canyon Wash, Dragoon Wash, Clifford Wash, San Pedro River, 
  Slavin Wash and Escalante Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3193 10997 3182 11003 3182 11017 3177 11036
      3187 11037 3196 11029 3202 11022 3203 11017
      3201 11014 3202 11009 3198 11001

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

$$

JRM
512 
WGUS55 KTWC 090321
FFWTWC
AZC003-090645-
/O.EXT.KTWC.FF.W.0096.000000T0000Z-210809T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
821 PM MST Sun Aug 8 2021

The National Weather Service in Tucson has extended the

* Flash Flood Warning for...
  West Central Cochise County in southeastern Arizona...

* Until 1145 PM MST.

* At 821 PM MST, Doppler radar indicated additional thunderstorms 
  with heavy rain developing in the warned area. Trained weather 
  spotters also reported flash flooding along Dragoon and Gila Wash 
  in the vicinity of St. David and Sibyl Road. Between 1 and 3 
  inches of rain have fallen. Additional rainfall amounts of 0.5 to 
  1 inch are possible in the warned area. Flash flooding is already 
  occurring.

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

  SOURCE...Trained spotters reported.

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

* Some locations that will experience flash flooding include...
  Benson, St. David and Kartchner Caverns State Park.

This includes the following Flash Flood Prone Locations...
	Sibyl Rd at Gila/Dragoon Wash.

This includes the following streams and drainages...
  Middle Canyon Wash, Dragoon Wash, Clifford Wash, San Pedro River, 
  Slavin Wash and Escalante Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3193 10997 3182 11003 3182 11017 3177 11036
      3187 11037 3196 11029 3202 11022 3203 11017
      3201 11014 3202 11009 3198 11001

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

JRM
564 
WGUS75 KTWC 090642
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
1142 PM MST Sun Aug 8 2021

AZC003-090652-
/O.EXP.KTWC.FF.W.0096.000000T0000Z-210809T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cochise AZ-
1142 PM MST Sun Aug 8 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1145 PM MST THIS EVENING FOR 
WEST CENTRAL COCHISE COUNTY...

Flood waters have receded. The heavy rain has ended. Flooding is no 
longer expected to pose a threat. Please continue to heed remaining 
road closures.

LAT...LON 3193 10997 3182 11003 3182 11017 3177 11036
      3187 11037 3196 11029 3202 11022 3203 11017
      3201 11014 3202 11009 3198 11001

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 5:03 PM MSTSpecial Weather StatementTWCCochise42 min
Aug 8, 5:18 PM MSTSpecial Weather StatementTWCSanta Cruz27 min
Aug 8, 5:22 PM MSTSpecial Weather StatementTWCPima38 min
Aug 8, 5:22 PM MSTSevere Thunderstorm WarningTWCCochise38 min
Aug 8, 5:28 PM MSTSpecial Weather StatementTWCCochise47 min
Aug 8, 5:51 PM MSTSpecial Weather StatementTWCPima24 min
Aug 8, 6:09 PM MSTSevere Thunderstorm WarningTWCCochise66 min
Aug 8, 6:10 PM MSTAreal Flood AdvisoryTWCPima2 hr
Aug 8, 6:13 PM MSTSpecial Weather StatementTWCPima32 min
Aug 8, 6:14 PM MSTSevere Thunderstorm WarningTWCCochise20 min
Aug 8, 6:19 PM MSTSevere Thunderstorm WarningTWCPima41 min
Aug 8, 6:37 PM MSTAreal Flood AdvisoryTWCCochise5 hr
Aug 8, 6:56 PM MSTDust Storm AdvisoryTWCCochise, Pima, Pinal70 min
Aug 8, 8:45 PM MSTSevere Thunderstorm WarningTWCPima, Santa Cruz45 min
Aug 8, 9:03 PM MSTFlash Flood Warning Considerable damage threatTWCPima117 min
Aug 8, 9:28 PM MSTAreal Flood AdvisoryTWCCochise, Pima, Santa Cruz2 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.