Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 51, NWS Tucson, AZ

July 18, 2021Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 18, 2021, 9:30 PM MST for 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, 9:30 PM MST (04:30 UTC)
Expired: Jul 19, 2021, 12:30 AM MST
In force: 3 hr
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Pima County, AZ

The radar

The Tucson radar (KEMX), 35 km from the middle of the area, began a volume at 04:31 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, 4.5 hours before the alert went out and 178 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.

091 
WGUS55 KTWC 190430
FFWTWC
AZC019-190730-
/O.NEW.KTWC.FF.W.0051.210719T0430Z-210719T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Tucson has issued a

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

* Until 1230 AM MST.

* At 930 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 3 inches of rain 
  have fallen. A stream gauge at Pantano Wash in Vail has reached 8 
  feet. This will likely lead to flooding in low lying areas along 
  the Pantano Wash in the warned area including at Harrison Rd.

  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...
  Tucson and Saguaro National Park East.
  Intersection of Pantano Wash and Harrison Rd

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.

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 3220 11082 3220 11080 3218 11077 3215 11072
      3213 11075 3217 11080

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

$$

AH

2 follow-up statements

282 
WGUS75 KTWC 190535
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
1035 PM MST Sun Jul 18 2021

AZC019-190730-
/O.CON.KTWC.FF.W.0051.000000T0000Z-210719T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
1035 PM MST Sun Jul 18 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1230 AM MST MONDAY 
FOR EAST CENTRAL PIMA COUNTY...

At 1035 PM MST, Doppler radar indicated thunderstorms producing 
heavy rain across the warned area. Between 1 and 3 inches of rain 
have fallen. The Pantano stream gauge in Vail was at 8 feet at 915 
PM MST. Flash flooding along low lying areas and street crossings 
near the Pantano is expected or is ongoing.

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...
  Tucson and Saguaro National Park East.
  Intersection of Pantano Wash and Harrison Rd

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.

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 3220 11082 3220 11080 3218 11077 3215 11072
      3213 11075 3217 11080

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

$$

AH

648 
WGUS75 KTWC 190725
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
1225 AM MST Mon Jul 19 2021

AZC019-190735-
/O.EXP.KTWC.FF.W.0051.000000T0000Z-210719T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
1225 AM MST Mon Jul 19 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1230 AM MST EARLY THIS MORNING 
FOR EAST CENTRAL PIMA COUNTY...

The heavy rain has ended and flood waters were receding. That said, 
flooding is no longer expected to pose a threat. Please continue to 
heed remaining road closures.

LAT...LON 3220 11082 3220 11080 3218 11077 3215 11072
      3213 11075 3217 11080

$$

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, 7:00 PM MST	Flash Flood Warning Considerable damage threat	TWC	Cochise, 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 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.