Alert archive / Arizona / Flash Flood Warnings in 2021
Flash Flood Warning 149, NWS Phoenix, AZ
NWS Phoenix, AZ issued this flash flood warning at Aug 11, 2021, 5:30 PM MST for Maricopa County, Arizona. It was in force for 2 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, 5:30 PM MST (00:30 UTC)
- Expired
- Aug 11, 2021, 7:56 PM MST
- In force
- 2 hr
- Issued by
- NWS Phoenix, AZ
- Area
- Storm-based polygon
- Flood severity
- None
County Maricopa County, AZ
The radar
The Phoenix radar (KIWA), 47 km from the middle of the area, began a volume at 00:33 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, 5:49 PM MST | HEAVY RAIN 1.5 | 7 Ene Glendale, AZ | ALSO RECORDED 0.70 IN ABOUT 20 MINUTES. |
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, 0.5 hours before the alert went out and 17 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.
409
WGUS55 KPSR 120030
FFWPSR
AZC013-120400-
/O.NEW.KPSR.FF.W.0149.210812T0030Z-210812T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
530 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 900 PM MST.
* At 530 PM MST, Doppler radar indicated thunderstorms producing
heavy rain across the warned area. Between 0.5 and 1.5 inches of
rain have fallen. Flash flooding is ongoing or expected to begin
shortly.
HAZARD...Flash flooding caused by thunderstorms.
SOURCE...Radar.
IMPACT...Flash flooding of small creeks and streams, urban
areas, highways, streets and underpasses as well as
other poor drainage and low-lying areas.
* Some locations that will experience flash flooding include...
Phoenix, Glendale, Paradise Valley, North Mountain Park, Piestewa
Peak Park, Metro Center Mall and Camelback Mountain.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3362 11214 3363 11204 3363 11201 3356 11195
3351 11195 3348 11202 3348 11210 3354 11218
FLASH FLOOD...RADAR INDICATED
$$
MS1 follow-up statement
587
WGUS75 KPSR 120256
FFSPSR
Flash Flood Statement
National Weather Service Phoenix AZ
756 PM MST Wed Aug 11 2021
AZC013-120306-
/O.CAN.KPSR.FF.W.0149.000000T0000Z-210812T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
756 PM MST Wed Aug 11 2021
...FLASH FLOOD WARNING IS CANCELLED FOR MARICOPA COUNTY...
The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
LAT...LON 3362 11214 3363 11204 3363 11201 3356 11195
3351 11195 3348 11202 3348 11210 3354 11218
$$
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 | Severe Thunderstorm Warning | PSR | Maricopa, Pinal | 45 min |
| Aug 11, 5:39 PM MST | Flash Flood Warning | PSR | Maricopa | 3 hr |
| 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.