Alert archive / Arizona / Flash Flood Warnings in 2021
Flash Flood Warning 150, NWS Phoenix, AZ
NWS Phoenix, AZ issued this flash flood warning at Aug 11, 2021, 5:39 PM MST for Maricopa 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
- Aug 11, 2021, 5:39 PM MST (00:39 UTC)
- Expired
- Aug 11, 2021, 8:33 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), 110 km from the middle of the area, began a volume at 00:43 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, 0.7 hours before the alert went out and 85 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
- 1157 J/kg
- Mixed-layer CIN
- -4 J/kg
- Mixed-layer LCL
- 1687 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- -3 m²/s²
- 0-3 km storm-relative helicity
- 52 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
038
WGUS55 KPSR 120039
FFWPSR
AZC013-120445-
/O.NEW.KPSR.FF.W.0150.210812T0039Z-210812T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
539 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 945 PM MST.
* At 539 PM MST, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 0.5 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.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
* Some locations that will experience flash flooding include...
Buckeye and Painted Rock Dam.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3307 11275 3313 11289 3323 11301 3331 11305
3337 11300 3338 11286 3328 11272 3316 11266
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
MS2 follow-up statements
901
WGUS75 KPSR 120302
FFSPSR
Flash Flood Statement
National Weather Service Phoenix AZ
802 PM MST Wed Aug 11 2021
AZC013-120445-
/O.CON.KPSR.FF.W.0150.000000T0000Z-210812T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
802 PM MST Wed Aug 11 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 PM MST THIS
EVENING FOR MARICOPA COUNTY...
At 802 PM MST, Doppler radar indicated thunderstorms producing heavy
rain in Winters Wash. Between 0.5 and 2 inches of rain had fallen.
Flash flooding is ongoing or expected to begin shortly.
HAZARD...Life threatening flash flooding. Thunderstorms producing
flash flooding.
SOURCE...Radar.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that will experience flash flooding include...
Buckeye and Painted Rock Dam.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3307 11275 3313 11289 3323 11301 3331 11305
3337 11300 3338 11286 3328 11272 3316 11266
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
MS161
WGUS75 KPSR 120333
FFSPSR
Flash Flood Statement
National Weather Service Phoenix AZ
833 PM MST Wed Aug 11 2021
AZC013-120343-
/O.CAN.KPSR.FF.W.0150.000000T0000Z-210812T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
833 PM MST Wed Aug 11 2021
...FLASH FLOOD WARNING IS CANCELLED FOR MARICOPA COUNTY...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
LAT...LON 3307 11275 3313 11289 3323 11301 3331 11305
3337 11300 3338 11286 3328 11272 3316 11266
$$
MSThe office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 5:03 PM MST | Severe Thunderstorm Warning | PSR | Maricopa | 42 min |
| Aug 11, 5:14 PM MST | Flash Flood Warning | PSR | Maricopa | 3 hr |
| Aug 11, 5:14 PM MST | Special Weather Statement | PSR | Maricopa | 46 min |
| Aug 11, 5:30 PM MST | Flash Flood Warning | PSR | Maricopa | 2 hr |
| Aug 11, 5:30 PM MST | Severe Thunderstorm Warning | PSR | Maricopa, Pinal | 45 min |
| Aug 11, 5:49 PM MST | Special Weather Statement | PSR | 41 min | |
| Aug 11, 5:57 PM MST | Flash Flood Warning | PSR | Maricopa | 6 hr |
| Aug 11, 6:07 PM MST | Dust Storm Warning | PSR | Maricopa, Pinal | 53 min |
| Aug 11, 6:12 PM MST | Severe Thunderstorm Warning | PSR | Maricopa, Pinal | 48 min |
| Aug 11, 6:19 PM MST | Severe Thunderstorm Warning | PSR | Maricopa | 41 min |
| Aug 11, 6:20 PM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 11, 6:40 PM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 11, 7:02 PM MST | Special Weather Statement | PSR | 58 min | |
| Aug 11, 7:11 PM MST | Special Weather Statement | PSR | 64 min | |
| Aug 11, 7:26 PM MST | Flash Flood Warning | PSR | La Paz | 3 hr |
| Aug 11, 7:53 PM MST | Special Weather Statement | PSR | La Paz | 37 min |
| Aug 12, 2:00 AM MST | Special Weather Statement | PSR | 45 min | |
| Aug 12, 2:42 AM MST | Flash Flood Warning | PSR | Gila, Maricopa | 4 hr |
| Aug 12, 2:45 AM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Aug 12, 3:34 AM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Aug 12, 4:16 AM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 12, 4:33 AM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 12, 5:17 AM MST | Flash Flood Warning | PSR | Maricopa | 6 hr |
| Aug 12, 6:04 AM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 12, 6:21 AM MST | Areal Flood Advisory | PSR | Maricopa | 46 min |
| Aug 12, 7:00 AM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 12, 10:09 AM MST | Areal Flood Warning | PSR | Gila | 8 hr |
| Aug 12, 10:46 AM MST | Areal Flood Warning | PSR | Maricopa | 15 hr |
| Aug 12, 1:30 PM MST | Flash Flood Watch | PSR | Gila, Maricopa, Pinal | 5 days |
| Aug 12, 2:11 PM MST | Special Weather Statement | PSR | La Paz | 34 min |
| Aug 12, 2:30 PM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Aug 12, 2:45 PM MST | Areal Flood Advisory | PSR | La Paz | 3 hr |
| Aug 12, 2:54 PM MST | Flash Flood Warning | PSR | La Paz, Maricopa | 4 hr |
| Aug 12, 3:11 PM MST | Flash Flood Warning | PSR | Maricopa | 5 hr |
| Aug 12, 3:34 PM MST | Special Weather Statement | PSR | 41 min | |
| Aug 12, 4:14 PM MST | Areal Flood Advisory | PSR | Maricopa, Yuma | 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.