Alert archive / Arizona / Flash Flood Warnings in 2021
Flash Flood Warning 146, NWS Phoenix, AZ
NWS Phoenix, AZ issued this flash flood warning at Aug 11, 2021, 4:01 PM MST for Maricopa 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
- Aug 11, 2021, 4:01 PM MST (23:01 UTC)
- Expired
- Aug 11, 2021, 7:00 PM MST
- In force
- 3 hr
- Issued by
- NWS Phoenix, AZ
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
County Maricopa County, AZ
The radar
The Phoenix radar (KIWA), 129 km from the middle of the area, began a volume at 23:04 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 |
|---|---|---|---|
| Aug 11, 4:55 PM MST | FLASH FLOOD | 2 W Wickenburg, AZ | PHOTO ON SOCIAL MEDIA OF FLASH FLOODING IN FLYING E WASH WITH SIGNIFICANT FLOW OVER VULTURE MINE ROAD, RESULTING IN THE CLOSURE OF THE ROAD. |
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 12:00Z, 11.0 hours before the alert went out and 97 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.
- Mixed-layer CAPE
- 735 J/kg
- Mixed-layer CIN
- -36 J/kg
- Mixed-layer LCL
- 905 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 12 m²/s²
- 0-3 km storm-relative helicity
- 53 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
887
WGUS55 KPSR 112301
FFWPSR
AZC013-120200-
/O.NEW.KPSR.FF.W.0146.210811T2301Z-210812T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
401 PM MST Wed Aug 11 2021
The National Weather Service in Phoenix has issued a
* Flash Flood Warning for...
Maricopa County in south central Arizona...
* Until 700 PM MST.
* At 401 PM MST, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between
1 and 1.5 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 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...
Wickenburg.
This includes the following streams and drainages...
Jackrabbit Wash, Hartman Wash, Flying E Wash, Star Wash, Jimmie
Wash, Mill Wash, Sols Wash, Powerline Wash, Cemetery Wash, Red
Cloud Wash, and Daggs Wash.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3400 11285 3398 11274 3395 11271 3378 11290
3383 11297
FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
AJ1 follow-up statement
655
WGUS75 KPSR 112319
FFSPSR
Flash Flood Statement
National Weather Service Phoenix AZ
419 PM MST Wed Aug 11 2021
AZC013-120200-
/O.CON.KPSR.FF.W.0146.000000T0000Z-210812T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
419 PM MST Wed Aug 11 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 7 PM MST THIS EVENING
FOR MARICOPA COUNTY...
At 419 PM MST, Doppler radar and automated rain gauges indicated
thunderstorms producing heavy rain across the warned area. Between 1
and 2 inches of rain have fallen. Flash flooding is ongoing or
expected to begin shortly.
HAZARD...Life threatening flash flooding. Thunderstorms producing
flash flooding.
SOURCE...Radar and automated gauges.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that will experience flash flooding include...
Wickenburg.
This includes the following streams and drainages...
Jackrabbit Wash, Hartman Wash, Flying E Wash, Star Wash, Jimmie
Wash, Mill Wash, Sols Wash, Powerline Wash, Cemetery Wash, Red
Cloud Wash, and Daggs Wash.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3400 11285 3398 11274 3395 11271 3378 11290
3383 11297
FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
AJThe office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 10, 5:23 PM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Aug 10, 5:35 PM MST | Special Weather Statement | PSR | 40 min | |
| Aug 10, 5:51 PM MST | Areal Flood Advisory | PSR | La Paz | 3 hr |
| Aug 10, 5:55 PM MST | Special Weather Statement | PSR | La Paz | 50 min |
| Aug 10, 6:30 PM MST | Severe Thunderstorm Warning | PSR | La Paz, Yuma | 45 min |
| Aug 10, 6:36 PM MST | Flash Flood Warning | PSR | La Paz, Maricopa | 4 hr |
| Aug 10, 7:15 PM MST | Dust Storm Warning | PSR | La Paz, Yuma | 60 min |
| Aug 10, 7:26 PM MST | Severe Thunderstorm Warning | PSR | La Paz, Maricopa, Yuma | 49 min |
| Aug 10, 7:33 PM MST | Flash Flood Warning | PSR | La Paz, Yuma | 4 hr |
| Aug 10, 7:43 PM MST | Dust Storm Advisory | PSR | Maricopa, Pinal, Yuma | 62 min |
| Aug 10, 8:18 PM MST | Severe Thunderstorm Warning | PSR | La Paz, Yuma | 57 min |
| Aug 10, 8:38 PM MST | Dust Storm Warning | PSR | La Paz, Yuma | 52 min |
| Aug 10, 9:08 PM MST | Flash Flood Warning | PSR | La Paz, Yuma | 6 hr |
| Aug 10, 9:12 PM MST | Flash Flood Warning | PSR | Maricopa, Yuma | 6 hr |
| Aug 10, 9:23 PM MST | Special Weather Statement | PSR | Yuma | 97 min |
| Aug 10, 9:42 PM MST | Dust Storm Warning | PSR | Yuma | 93 min |
| Aug 10, 10:35 PM MST | Flash Flood Warning | PSR | La Paz, Maricopa, Yuma | 6 hr |
| Aug 11, 12:01 AM MST | Flash Flood Warning | PSR | La Paz, Yuma | 5 hr |
| Aug 11, 2:00 AM MST | Areal Flood Advisory | PSR | Gila | 3 hr |
| Aug 11, 3:29 AM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Aug 11, 4:33 AM MST | Areal Flood Advisory | PSR | Maricopa, Pinal | 3 hr |
| Aug 11, 6:06 AM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Aug 11, 6:11 AM MST | Areal Flood Advisory | PSR | Maricopa, Pinal | 3 hr |
| Aug 11, 6:15 AM MST | Areal Flood Advisory | PSR | Gila, Maricopa | 3 hr |
| Aug 11, 7:30 AM MST | Flash Flood Warning | PSR | Gila, Maricopa | 6 hr |
| Aug 11, 7:46 AM MST | Areal Flood Advisory | PSR | Maricopa, Pinal | 3 hr |
| Aug 11, 8:12 AM MST | Flash Flood Warning | PSR | Maricopa, Pinal | 6 hr |
| Aug 11, 9:13 AM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Aug 11, 1:01 PM MST | Special Weather Statement | PSR | Yuma | 59 min |
| Aug 11, 1:29 PM MST | Areal Flood Warning | PSR | Maricopa | 6 hr |
| Aug 11, 1:43 PM MST | Areal Flood Warning | PSR | Gila | 4 hr |
| Aug 11, 1:49 PM MST | Areal Flood Advisory | PSR | Yuma | 3 hr |
| Aug 11, 2:01 PM MST | Dust Storm Advisory | PSR | Yuma | 59 min |
| Aug 11, 2:17 PM MST | Severe Thunderstorm Warning | PSR | Yuma | 43 min |
| Aug 11, 3:02 PM MST | Flash Flood Warning | PSR | Yuma | 4 hr |
| Aug 11, 3:11 PM MST | Special Weather Statement | PSR | 64 min | |
| Aug 11, 3:29 PM MST | Special Weather Statement | PSR | Maricopa | 46 min |
| Aug 11, 3:34 PM MST | Special Weather Statement | PSR | 56 min | |
| Aug 11, 3:44 PM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Aug 11, 3:47 PM MST | Areal Flood Advisory | PSR | Maricopa | 14 min |
| Aug 11, 3:50 PM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Aug 11, 4:33 PM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Aug 11, 4:44 PM MST | Dust Storm Advisory | PSR | Maricopa, Pinal | 61 min |
| Aug 11, 4:56 PM MST | Flash Flood Warning | PSR | Maricopa | 3 hr |
Nearby
Flash Flood Warnings in Arizona, 2021Every 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.