Alert archive / Arizona / Flash Flood Warnings in 2021
Flash Flood Warning 133, NWS Phoenix, AZ
NWS Phoenix, AZ issued this flash flood warning at Aug 10, 2021, 8:00 AM MST for Maricopa County, Arizona. It was in force for 3 hr. 3 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, 8:00 AM MST (15:00 UTC)
- Expired
- Aug 10, 2021, 11:26 AM 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), 12 km from the middle of the area, began a volume at 15:03 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, 8:05 AM MST | HEAVY RAIN 0.95 | 3 Wsw Higley, AZ | A TRAINED SPOTTER IN GILBERT MEASURED 0.95 INCHES OF RAIN BETWEEN 735 AM AND 805 AM NEAR LINDSAY ROAD AND PECOS RD. THE STORM TOTAL BETWEEN 720AM AND 905 AM WAS 1.34 INCHES. |
| Aug 10, 8:29 AM MST | FLASH FLOOD | 4 Wsw Higley, AZ | LOOP-202 WESTBOUND EXIT RAMP TO GILBERT ROAD CLOSED DUE TO FLOODING. |
| Aug 10, 9:05 AM MST | HEAVY RAIN 2.72 | 3 Se Chandler, AZ | 2.72 INCHES FELL BETWEEN 7:00 AND 9:05 AM. 2.13 INCHES IN 1 HOUR (BETWEEN 7:17 AND 8:17 AM) AT CHANDLER AIRPORT FCDMC AZ ALERT GAGE. |
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, 3.0 hours before the alert went out and 22 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.
077
WGUS55 KPSR 101500
FFWPSR
AZC013-101900-
/O.NEW.KPSR.FF.W.0133.210810T1500Z-210810T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
800 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...
* Until noon MST.
* At 800 AM 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. The expected rainfall rate
is 0.75 to 1.5 inches in 1 hour. Additional rainfall amounts of
0.5 to 1.5 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...
Mesa, Chandler, Gilbert, Queen Creek, Tumbleweed Park, Gilbert
City Hall, Chandler City Hall, San Tan Village Mall and Higley.
This includes the following highways...
AZ Route 202 between mile markers 40 and 49.
AZ Route 87 between mile markers 161 and 166.
This includes the following streams and drainages...
Queen Creek.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 3332 11184 3334 11178 3329 11166 3324 11175
3322 11184 3328 11191
FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...0.75-1.5 INCHES IN 1 HOUR
$$
SDB2 follow-up statements
126
WGUS75 KPSR 101536
FFSPSR
Flash Flood Statement
National Weather Service Phoenix AZ
836 AM MST Tue Aug 10 2021
AZC013-101900-
/O.CON.KPSR.FF.W.0133.000000T0000Z-210810T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
836 AM MST Tue Aug 10 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL NOON MST TODAY FOR
MARICOPA COUNTY...
At 836 AM MST, Doppler radar and automated rain gauges indicated
that heavy rain was falling across the warned area. Between 2 and
2.5 inches of rain have fallen. Additional rainfall amounts of 0.25
to 0.75 inches are possible in the warned area. Flash flooding is
ongoing or expected to begin shortly.
HAZARD...Life threatening flash flooding. Heavy rain producing
flash flooding.
SOURCE...Radar and automated gauges.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that will experience flash flooding include...
Mesa, Chandler, Gilbert, Queen Creek, Tumbleweed Park, Gilbert
City Hall, Chandler City Hall, San Tan Village Mall and Higley.
This includes the following highways...
AZ Route 202 between mile markers 40 and 49.
AZ Route 87 between mile markers 161 and 167.
This includes the following streams and drainages...
Queen Creek.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
Be aware of your surroundings and do not drive on flooded roads.
&&
LAT...LON 3332 11184 3334 11178 3329 11166 3324 11175
3322 11184 3328 11191
FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
SDB936
WGUS75 KPSR 101826
FFSPSR
Flash Flood Statement
National Weather Service Phoenix AZ
1126 AM MST Tue Aug 10 2021
AZC013-101836-
/O.CAN.KPSR.FF.W.0133.000000T0000Z-210810T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
1126 AM MST Tue Aug 10 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 3332 11184 3334 11178 3329 11166 3324 11175
3322 11184 3328 11191
$$
SDBThe 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, 8:06 AM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 10, 8:30 AM MST | Flash Flood Warning | PSR | Maricopa, Pinal | 7 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.