Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 50, NWS Tucson, AZ

July 18, 2021Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Jul 18, 2021, 8:20 PM MST for Pima County, Arizona. It was in force for 3 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 18, 2021, 8:20 PM MST (03:20 UTC)
Expired: Jul 18, 2021, 11:30 PM 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), 18 km from the middle of the area, began a volume at 03:20 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 18, 8:33 PM MST	FLOOD	19 Se Tucson, AZ	FLOWING WATER ACROSS DIPS ON E SAHUARITA RD BETWEEN HOUGHTON AND HWY 83. SAHUARITA WAS PASSABLE.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 3.3 hours before the alert went out and 196 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.

451 
WGUS55 KTWC 190320
FFWTWC
AZC019-190630-
/O.NEW.KTWC.FF.W.0050.210719T0320Z-210719T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  Eastern Pima County in southeastern Arizona...

* Until 1130 PM MST.

* At 820 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. Automated gauges along the 
  Pantano have recorded over an inch in a half hour. Additional 
  rainfall amounts of 1 to 2 inches 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...
  Tucson, Vail and Saguaro National Park East.

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.

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

&&

LAT...LON 3197 11070 3196 11045 3215 11050 3215 11074
      3215 11077 3204 11073

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

$$

AH

2 follow-up statements

484 
WGUS75 KTWC 190504
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
1004 PM MST Sun Jul 18 2021

AZC019-190630-
/O.CON.KTWC.FF.W.0050.000000T0000Z-210719T0630Z/
/00000.U.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
1004 PM MST Sun Jul 18 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1130 PM MST THIS 
EVENING FOR EASTERN PIMA COUNTY...

At 1004 PM MST, Doppler radar and automated rain gauges 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 at least 8 feet. This could lead to flooding in low 
lying areas and road crossings near the Pantano Wash. 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...
  Tucson, Vail and Saguaro National Park East.

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.

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

&&

LAT...LON 3197 11070 3204 11073 3215 11077 3215 11074
      3215 11050 3196 11045

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

$$

AH

146 
WGUS75 KTWC 190626
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
1126 PM MST Sun Jul 18 2021

AZC019-190636-
/O.EXP.KTWC.FF.W.0050.000000T0000Z-210719T0630Z/
/00000.U.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
1126 PM MST Sun Jul 18 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1130 PM MST THIS EVENING FOR 
EASTERN PIMA COUNTY...

Flood waters continued to receded. The heavy rain has ended. 
Flooding is no longer expected to pose a threat in this area. A 
flash flood warning remains in effect until 1230 PM MST for the 
downstream portion of the Pantano Wash to Harrison Road. 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 3197 11070 3204 11073 3215 11077 3215 11074
      3215 11050 3196 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, 7:00 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, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.