Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 31, NWS Tucson, AZ

July 15, 2021Graham County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 15, 2021, 4:29 PM MST for Graham 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: Jul 15, 2021, 4:29 PM MST (23:29 UTC)
Expired: Jul 15, 2021, 6:30 PM MST
In force: 2 hr
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Graham County, AZ

The radar

The Tucson radar (KEMX), 142 km from the middle of the area, began a volume at 23:29 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

Time	Report	Where	Remark
Jul 15, 5:30 PM MST	FLASH FLOOD	3 N Thatcher, AZ	SHERIFF REPORTED MULTIPLE WASHOUTS AND/OR DEBRIS ACROSS THE THE SAFFORD-BRYCE ROAD AND THE N BRYCE-EDEN ROAD.

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, 11.5 hours before the alert went out and 138 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: 1024 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 1408 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 14 m²/s²
0-3 km storm-relative helicity: 41 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

224 
WGUS55 KTWC 152329
FFWTWC
AZC009-160130-
/O.NEW.KTWC.FF.W.0031.210715T2329Z-210716T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
429 PM MST Thu Jul 15 2021

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  Central Graham County in southeastern Arizona...

* Until 630 PM MST.

* At 429 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain in Coyote Wash and Watson Wash. Between 2 and 3 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.

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

* Some locations that will experience flash flooding include...
  Safford and Thatcher.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Move to higher ground now. Act quickly to protect your life.

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

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

&&

LAT...LON 3288 10968 3284 10971 3286 10977 3290 10979
      3290 10982 3303 10972 3297 10960 3290 10964

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

$$

CC

1 follow-up statement

185 
WGUS75 KTWC 160127
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
627 PM MST Thu Jul 15 2021

AZC009-160137-
/O.EXP.KTWC.FF.W.0031.000000T0000Z-210716T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Graham AZ-
627 PM MST Thu Jul 15 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 630 PM MST THIS EVENING FOR 
CENTRAL GRAHAM COUNTY...

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

A Flash Flood Watch remains in effect until 1100 PM MST Friday for a 
portion of Southeast Arizona.

LAT...LON 3288 10968 3284 10971 3286 10977 3290 10979
      3290 10982 3303 10972 3297 10960 3290 10964

$$

RH

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 14, 5:33 PM MST	Special Weather Statement	TWC		27 min
Jul 14, 5:41 PM MST	Special Weather Statement	TWC		49 min
Jul 15, 6:07 AM MST	Areal Flood Advisory	TWC	Pima	113 min
Jul 15, 6:33 AM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 15, 8:12 AM MST	Areal Flood Advisory	TWC	Pima	2 hr
Jul 15, 8:32 AM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 15, 8:40 AM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	114 min
Jul 15, 1:51 PM MST	Areal Flood Advisory	TWC	Cochise, Graham	3 hr
Jul 15, 1:55 PM MST	Special Weather Statement	TWC	Greenlee	35 min
Jul 15, 2:19 PM MST	Severe Thunderstorm Warning	TWC	Cochise, Graham	41 min
Jul 15, 2:31 PM MST	Areal Flood Advisory	TWC	Cochise	119 min
Jul 15, 2:52 PM MST	Severe Thunderstorm Warning	TWC	Cochise	38 min
Jul 15, 3:15 PM MST	Severe Thunderstorm Warning	TWC	Graham	45 min
Jul 15, 3:30 PM MST	Areal Flood Advisory	TWC	Graham, Greenlee	3 hr
Jul 15, 3:57 PM MST	Severe Thunderstorm Warning	TWC	Graham	33 min
Jul 15, 4:42 PM MST	Special Weather Statement	TWC	Graham	33 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.