Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 49, NWS Tucson, AZ

July 18, 2021Cochise County, Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 18, 2021, 7:00 PM MST for Cochise County, Pima 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: Jul 18, 2021, 7:00 PM MST (02:00 UTC)
Expired: Jul 18, 2021, 10:00 PM MST
In force: 3 hr
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Cochise County, AZ, Pima County, AZ

The radar

The Tucson radar (KEMX), 37 km from the middle of the area, began a volume at 02:01 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.

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 2.0 hours before the alert went out and 211 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: 1031 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 2190 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: -20 m²/s²
0-3 km storm-relative helicity: 86 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.2

Open this sounding in Storm Lab

The text

As transmitted.

048 
WGUS55 KTWC 190200
FFWTWC
AZC003-019-190500-
/O.NEW.KTWC.FF.W.0049.210719T0200Z-210719T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
700 PM MST Sun Jul 18 2021

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  Northwestern Cochise County in southeastern Arizona...
  East Central Pima County in southeastern Arizona...

* Until 1000 PM MST.

* At 700 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. 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,
           streets and underpasses.

* Some locations that will experience flash flooding include...
  Benson, Mescal and Cascabel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

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.

Remain alert for flooding even in locations not receiving rain. 
Washes, streams, and rivers can become raging killer currents in a 
matter of minutes, even from distant rainfall.

&&

LAT...LON 3200 11045 3204 11048 3210 11049 3225 11051
      3227 11050 3229 11047 3229 11034 3229 11024
      3228 11022 3224 11018 3219 11017 3208 11015
      3204 11016 3200 11018 3197 11026 3198 11031
      3196 11038 3197 11045

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

$$

CC

1 follow-up statement

112 
WGUS75 KTWC 190456
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
956 PM MST Sun Jul 18 2021

AZC003-019-190506-
/O.EXP.KTWC.FF.W.0049.000000T0000Z-210719T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Cochise AZ-Pima AZ-
956 PM MST Sun Jul 18 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 10 PM MST THIS EVENING FOR 
NORTHWESTERN COCHISE AND EAST CENTRAL PIMA COUNTIES...

The heavy rainfall that prompted the warning had ended. Flash 
flooding is no longer expected to pose a threat. However, please 
continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 1200 AM MST for a 
portion of Southeast Arizona.

LAT...LON 3200 11045 3204 11048 3210 11049 3225 11051
      3227 11050 3229 11047 3229 11034 3229 11024
      3228 11022 3224 11018 3219 11017 3208 11015
      3204 11016 3200 11018 3197 11026 3198 11031
      3196 11038 3197 11045

$$

JD

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 5:06 PM MST	Special Weather Statement	TWC		39 min
Jul 18, 5:10 PM MST	Special Weather Statement	TWC	Cochise	35 min
Jul 18, 5:27 PM MST	Severe Thunderstorm Warning	TWC	Cochise, Graham	48 min
Jul 18, 5:30 PM MST	Flash Flood Warning Considerable damage threat	TWC	Cochise	3 hr
Jul 18, 5:37 PM MST	Flash Flood Warning Considerable damage threat	TWC	Cochise, Graham, Greenlee	3 hr
Jul 18, 5:42 PM MST	Areal Flood Advisory	TWC	Cochise, Santa Cruz	3 hr
Jul 18, 5:46 PM MST	Special Weather Statement	TWC		44 min
Jul 18, 6:01 PM MST	Special Weather Statement	TWC	Cochise	59 min
Jul 18, 6:02 PM MST	Severe Thunderstorm Warning	TWC	Cochise, Santa Cruz	43 min
Jul 18, 6:06 PM MST	Flash Flood Warning Considerable damage threat	TWC	Cochise	2 hr
Jul 18, 6:11 PM MST	Areal Flood Advisory	TWC	Santa Cruz	3 hr
Jul 18, 6:12 PM MST	Severe Thunderstorm Warning	TWC	Cochise, Graham	48 min
Jul 18, 6:24 PM MST	Severe Thunderstorm Warning	TWC	Cochise, Pima	36 min
Jul 18, 6:33 PM MST	Flash Flood Warning Considerable damage threat	TWC	Cochise, Graham	3 hr
Jul 18, 6:39 PM MST	Special Weather Statement	TWC		66 min
Jul 18, 6:43 PM MST	Areal Flood Advisory	TWC	Cochise, Graham, Pima	3 hr
Jul 18, 7:07 PM MST	Severe Thunderstorm Warning	TWC	Cochise, Pima	38 min
Jul 18, 7:23 PM MST	Areal Flood Advisory	TWC	Cochise, Pima, Santa Cruz	3 hr
Jul 18, 7:29 PM MST	Severe Thunderstorm Warning	TWC	Pima	61 min
Jul 18, 7:36 PM MST	Special Weather Statement	TWC	Cochise	39 min
Jul 18, 7:45 PM MST	Areal Flood Advisory	TWC	Cochise	3 hr
Jul 18, 7:51 PM MST	Special Weather Statement	TWC		39 min
Jul 18, 8:20 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 18, 9:30 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 19, 3:23 PM MST	Special Weather Statement	TWC	Greenlee	22 min
Jul 19, 4:03 PM MST	Areal Flood Advisory	TWC	Greenlee	3 hr
Jul 19, 4:06 PM MST	Severe Thunderstorm Warning	TWC	Graham, Greenlee	39 min

Nearby

Flash Flood Warnings in Arizona, 2021 Every 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.