Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 43, NWS Tucson, AZ

July 18, 2021Graham County, Greenlee County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 18, 2021, 4:36 PM MST for Graham County, Greenlee 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, 4:36 PM MST (23:36 UTC)
Expired: Jul 18, 2021, 7:45 PM MST
In force: 3 hr
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Graham County, AZ, Greenlee County, AZ

The radar

The Tucson radar (KEMX), 147 km from the middle of the area, began a volume at 23:37 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, 11.6 hours before the alert went out and 151 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: 1146 J/kg
Mixed-layer CIN: -124 J/kg
Mixed-layer LCL: 1485 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -4 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

921 
WGUS55 KTWC 182336
FFWTWC
AZC009-011-190245-
/O.NEW.KTWC.FF.W.0043.210718T2336Z-210719T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Tucson has issued a

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

* Until 745 PM MST.

* At 436 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2.5 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, Solomon and Safford Regional Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3290 10959 3290 10938 3290 10930 3278 10934
      3270 10939 3269 10939 3257 10941 3260 10959
      3282 10966

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

$$

KRG

2 follow-up statements

583 
WGUS75 KTWC 190022
FFSTWC

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

AZC009-011-190245-
/O.CON.KTWC.FF.W.0043.000000T0000Z-210719T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Graham AZ-Greenlee AZ-
522 PM MST Sun Jul 18 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM MST THIS 
EVENING FOR SOUTHEASTERN GRAHAM AND CENTRAL GREENLEE COUNTIES...

At 522 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1 and 2.5 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, Solomon and Safford Regional Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3290 10959 3290 10938 3290 10930 3278 10934
      3270 10939 3269 10939 3257 10941 3260 10959
      3282 10966

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

$$

KRG

611 
WGUS75 KTWC 190235
FFSTWC

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

AZC009-011-190245-
/O.EXP.KTWC.FF.W.0043.000000T0000Z-210719T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Graham AZ-Greenlee AZ-
735 PM MST Sun Jul 18 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 745 PM MST THIS EVENING FOR 
SOUTHEASTERN GRAHAM AND CENTRAL GREENLEE COUNTIES...

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 1200 AM MST for a 
portion of Southeast Arizona.

LAT...LON 3290 10959 3290 10938 3290 10930 3278 10934
      3270 10939 3269 10939 3257 10941 3260 10959
      3282 10966

$$

KRG

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 6:50 PM MST	Special Weather Statement	TWC	Cochise	25 min
Jul 17, 8:04 PM MST	Special Weather Statement	TWC	Graham	41 min
Jul 17, 8:28 PM MST	Special Weather Statement	TWC	Cochise	32 min
Jul 18, 6:19 AM MST	Special Weather Statement	TWC	Santa Cruz	41 min
Jul 18, 7:55 AM MST	Areal Flood Advisory	TWC	Santa Cruz	3 hr
Jul 18, 11:57 AM MST	Areal Flood Advisory	TWC	Cochise	3 hr
Jul 18, 1:00 PM MST	Areal Flood Advisory	TWC	Graham	109 min
Jul 18, 1:28 PM MST	Flash Flood Watch	TWC	Cochise, Graham, Greenlee, Pima, Pinal, Santa Cruz	11 hr
Jul 18, 2:36 PM MST	Areal Flood Advisory	TWC	Graham	3 hr
Jul 18, 3:05 PM MST	Severe Thunderstorm Warning	TWC	Graham	40 min
Jul 18, 3:36 PM MST	Areal Flood Advisory	TWC	Graham	114 min
Jul 18, 4:08 PM MST	Flash Flood Warning Considerable damage threat	TWC	Greenlee	112 min
Jul 18, 4:10 PM MST	Special Weather Statement	TWC		35 min
Jul 18, 4:16 PM MST	Areal Flood Advisory	TWC	Graham, Greenlee	119 min
Jul 18, 4:21 PM MST	Areal Flood Advisory	TWC	Graham	114 min
Jul 18, 4:45 PM MST	Areal Flood Advisory	TWC	Cochise	2 hr
Jul 18, 4:50 PM MST	Severe Thunderstorm Warning	TWC	Cochise	40 min
Jul 18, 4:58 PM MST	Flash Flood Warning Considerable damage threat	TWC	Cochise	2 hr

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.