Alert archive / Arizona / Flash Flood Warnings in 2021
Flash Flood Warning 135, NWS Phoenix, AZ
NWS Phoenix, AZ issued this flash flood warning at Aug 10, 2021, 8:30 AM MST for Maricopa County, Pinal County, Arizona. It was in force for 7 hr. 2 reports 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 10, 2021, 8:30 AM MST (15:30 UTC)
- Expired
- Aug 10, 2021, 3:05 PM MST
- In force
- 7 hr
- Issued by
- NWS Phoenix, AZ
- Area
- Storm-based polygon
- Damage threat
- Considerable
- Flood severity
- None
Counties Maricopa County, AZ, Pinal County, AZ
The radar
The Phoenix radar (KIWA), 66 km from the middle of the area, began a volume at 15:29 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 10, 12:20 PM MST | FLASH FLOOD | 3 Sw Ak-Chin Village, AZ | CORRECTS TIME OF PREVIOUS FLASH FLOOD REPORT FROM 3 SW AK-CHIN VILLAGE. A PINAL COUNTY STREAM GAUGE ON VEKOL WASH AT RALSTON ROAD REGISTERED AN ABRUPT TWO FOOT RISE. A WEBCAM VIEW AT THE GAUGE SITE SHOWED A SUBSTANTIAL FLOW OF WATER OVER THE ROAD WHICH IS UNBR |
| Aug 10, 12:35 PM MST | FLASH FLOOD | 3 Sw Ak-Chin Village, AZ | A PINAL COUNTY STREAM GAUGE ON VEKOL WASH AT RALSTON ROAD REGISTERED AN ABRUPT TWO FOOT RISE. A WEBCAM VIEW AT THE GAUGE SITE SHOWED A SUBSTANTIAL FLOW OF WATER OVER THE ROAD WHICH IS UNBRIDGED. |
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, 3.5 hours before the alert went out and 64 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
- 110 J/kg
- Mixed-layer CIN
- -193 J/kg
- Mixed-layer LCL
- 1490 m above ground
- 0-6 km bulk shear
- 9 kt
- 0-1 km storm-relative helicity
- 11 m²/s²
- 0-3 km storm-relative helicity
- 93 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
344
WGUS55 KPSR 101530
FFWPSR
AZC013-021-102015-
/O.NEW.KPSR.FF.W.0135.210810T1530Z-210810T2015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
830 AM MST Tue Aug 10 2021
The National Weather Service in Phoenix has issued a
* Flash Flood Warning for...
Maricopa County in south central Arizona...
Pinal County in southeastern Arizona...
* Until 115 PM MST.
* At 830 AM MST, gauge reports indicated heavy rain fell in Vekol
Wash. The streamgauge in Vekol Wash along Interstate-8 has
exceeded alarm stage. Floodwaters may impact SR-238 in Maricopa
and Ak-Chin Village in 4 to 5 hrs. Additional rainfall amounts of
0.25 to 0.75 inches are possible in the warned area. Flash
flooding is ongoing or expected to begin shortly.
HAZARD...Life threatening flash flooding. Heavy rain producing
flash flooding.
SOURCE...Gauges reported.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
* Some locations that will experience flash flooding include...
Maricopa and Ak-Chin Village.
This includes the following highways...
AZ Route 238 between mile markers 41 and 43.
AZ Route 347 between mile markers 167 and 170.
AZ Interstate 8 between mile markers 143 and 148.
This includes the following streams and drainages...
Waterman Wash and Vekol Wash.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3269 11225 3284 11229 3288 11229 3298 11223
3309 11210 3307 11205 3296 11204 3292 11218
3270 11220
FLASH FLOOD...GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
SDB3 follow-up statements
539
WGUS75 KPSR 101648
FFSPSR
Flash Flood Statement
National Weather Service Phoenix AZ
948 AM MST Tue Aug 10 2021
AZC013-021-102015-
/O.CON.KPSR.FF.W.0135.000000T0000Z-210810T2015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-Pinal AZ-
948 AM MST Tue Aug 10 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 115 PM MST THIS
AFTERNOON FOR MARICOPA AND PINAL COUNTIES...
At 948 AM MST, gauge reports indicated that heavy rain fell in Vekol
Wash. The streamflow gauge in Vekol Wash along Interstate-8 has
fallen below alarm stage, but a flood wave may still continue to
push downstream and reach the Ak-Chin Village and Maricopa areas in
the next 2 to 4 hours. Flash flooding is ongoing or expected to
begin shortly.
HAZARD...Life threatening flash flooding. Heavy rain producing
flash flooding.
SOURCE...Gauges reported.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that will experience flash flooding include...
Maricopa and Ak-Chin Village.
This includes the following highways...
AZ Route 238 between mile markers 41 and 43.
AZ Route 347 between mile markers 167 and 173.
AZ Interstate 8 between mile markers 143 and 148.
This includes the following streams and drainages...
Waterman Wash and Vekol Wash.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3284 11229 3288 11229 3298 11222 3309 11210
3307 11205 3296 11204 3292 11218 3283 11219
FLASH FLOOD...GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
SDB236
WGUS55 KPSR 101954
FFWPSR
AZC013-021-102215-
/O.EXT.KPSR.FF.W.0135.000000T0000Z-210810T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
1254 PM MST Tue Aug 10 2021
The National Weather Service in Phoenix has extended the
* Flash Flood Warning for...
Maricopa County in south central Arizona...
Pinal County in southeastern Arizona...
* Until 315 PM MST.
* At 1254 PM MST, gauge reports indicated that heavy rain fell in
Vekol Wash. A Pinal County Flood Control District webcam along
Vekol Wash at Ralston Road in the Ak-Chin area shows 1-2 feet of
flowing water over Ralston Road. Flash flooding is already
occurring.
HAZARD...Life threatening flash flooding. Heavy rain producing
flash flooding.
SOURCE...Gauges reported.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
* Some locations that will experience flash flooding include...
Maricopa and Ak-Chin Village.
This includes the following highways...
AZ Route 238 between mile markers 41 and 42.
AZ Interstate 8 between mile markers 143 and 146.
This includes the following streams and drainages...
Vekol Wash.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3284 11229 3288 11228 3298 11221 3298 11220
3301 11212 3309 11210 3308 11208 3305 11205
3298 11205 3296 11211 3294 11220 3284 11223
FLASH FLOOD...GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
SDB886
WGUS75 KPSR 102205
FFSPSR
Flash Flood Statement
National Weather Service Phoenix AZ
305 PM MST Tue Aug 10 2021
AZC013-021-102215-
/O.CAN.KPSR.FF.W.0135.000000T0000Z-210810T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-Pinal AZ-
305 PM MST Tue Aug 10 2021
...FLASH FLOOD WARNING FOR MARICOPA AND PINAL COUNTIES HAS BEEN
REPLACED WITH A FLOOD WARNING...
Vekol Wash continues to flow and cause unbridged crossings to be
impassable for the next few hours.
LAT...LON 3284 11229 3288 11228 3298 11221 3298 11220
3301 11212 3309 11210 3308 11208 3305 11205
3298 11205 3296 11211 3294 11220 3284 11223
$$
AJThe office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 9, 5:24 PM MST | Areal Flood Advisory | PSR | La Paz | 3 hr |
| Aug 9, 5:44 PM MST | Special Weather Statement | PSR | La Paz | 46 min |
| Aug 9, 6:22 PM MST | Special Weather Statement | PSR | 38 min | |
| Aug 9, 10:11 PM MST | Special Weather Statement | PSR | Gila | 34 min |
| Aug 9, 10:40 PM MST | Flash Flood Warning | PSR | Gila | 4 hr |
| Aug 9, 11:51 PM MST | Flash Flood Warning | PSR | Maricopa | 8 hr |
| Aug 10, 1:40 AM MST | Special Weather Statement | PSR | Maricopa | 50 min |
| Aug 10, 1:54 AM MST | Special Weather Statement | PSR | Maricopa | 51 min |
| Aug 10, 2:15 AM MST | Special Weather Statement | PSR | Maricopa | 45 min |
| Aug 10, 2:23 AM MST | Areal Flood Advisory | PSR | Maricopa, Pinal | 2 hr |
| Aug 10, 4:27 AM MST | Special Weather Statement | PSR | La Paz | 48 min |
| Aug 10, 5:07 AM MST | Special Weather Statement | PSR | La Paz | 53 min |
| Aug 10, 5:09 AM MST | Areal Flood Advisory | PSR | La Paz | 2 hr |
| Aug 10, 5:52 AM MST | Areal Flood Advisory | PSR | Maricopa, Pinal | 5 hr |
| Aug 10, 6:21 AM MST | Special Weather Statement | PSR | La Paz | 39 min |
| Aug 10, 7:39 AM MST | Areal Flood Advisory | PSR | Maricopa, Pinal | 3 hr |
| Aug 10, 8:00 AM MST | Flash Flood Warning | PSR | Maricopa | 3 hr |
| Aug 10, 8:06 AM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 10, 9:54 AM MST | Areal Flood Advisory | PSR | La Paz | 3 hr |
| Aug 10, 3:05 PM MST | Areal Flood Warning | PSR | Maricopa, Pinal | 7 hr |
| Aug 10, 4:43 PM MST | Special Weather Statement | PSR | 62 min | |
| Aug 10, 4:44 PM MST | Special Weather Statement | PSR | 61 min | |
| Aug 10, 4:56 PM MST | Severe Thunderstorm Warning | PSR | Maricopa | 49 min |
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.