Alert archive / Arizona / Flash Flood Warnings in 2021
Flash Flood Warning 240, NWS Phoenix, AZ
NWS Phoenix, AZ issued this flash flood warning at Sep 1, 2021, 1:07 AM MST for Maricopa County, Arizona. It was in force for 5 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
- Sep 1, 2021, 1:07 AM MST (08:07 UTC)
- Expired
- Sep 1, 2021, 6:00 AM MST
- In force
- 5 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), 150 km from the middle of the area, began a volume at 08:07 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 |
|---|---|---|---|
| Sep 1, 3:37 AM MST | FLASH FLOOD | 9 Nne Centennial, AZ | A MARICOPA COUNTY FLOOD CONTROL DISTRICT STREAM GAUGE ON TIGER WASH EXCEEDED ALARM STAGE AT 232 AM CREATING A FLOODING PROBLEM ON EAGLE EYE ROAD DOWNSTREAM AN ESTIMATED 65 MINUTES LATER. |
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, 8.1 hours before the alert went out and 119 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
- 70 J/kg
- Mixed-layer CIN
- -132 J/kg
- Mixed-layer LCL
- 1562 m above ground
- 0-6 km bulk shear
- 29 kt
- 0-1 km storm-relative helicity
- -43 m²/s²
- 0-3 km storm-relative helicity
- 95 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
689
WGUS55 KPSR 010807
FFWPSR
AZC013-011300-
/O.NEW.KPSR.FF.W.0240.210901T0807Z-210901T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
107 AM MST Wed Sep 1 2021
The National Weather Service in Phoenix has issued a
* Flash Flood Warning for...
Maricopa County in south central Arizona...
* Until 600 AM MST.
* At 107 AM MST, Doppler radar indicated thunderstorms producing
heavy rain across northwestern Maricopa County within the Tiger
Wash and Centennial Wash. Up to 1 inch of rain has fallen.
Additional rainfall amounts up to 1 inch 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.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
* Some locations that will experience flash flooding include...
mainly rural areas of Maricopa County
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
&&
LAT...LON 3384 11333 3388 11319 3381 11309 3373 11311
3358 11326 3354 11322 3347 11313 3339 11308
3337 11311 3351 11333 3380 11333 3381 11333
3383 11333
FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
CK2 follow-up statements
949
WGUS75 KPSR 010955
FFSPSR
Flash Flood Statement
National Weather Service Phoenix AZ
255 AM MST Wed Sep 1 2021
AZC013-011300-
/O.CON.KPSR.FF.W.0240.000000T0000Z-210901T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
255 AM MST Wed Sep 1 2021
...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 AM MST EARLY THIS
MORNING FOR MARICOPA COUNTY...
At 255 AM MST, Doppler radar and automated rain gauges indicated
thunderstorms produced heavy rain in Tiger Wash and Centennial Wash.
Up to 1 inch of rain has fallen. Flash flooding is ongoing or
expected to begin shortly.
HAZARD...Life threatening flash flooding. Thunderstorms producing
flash flooding.
SOURCE...Radar and automated gauges.
IMPACT...Life threatening flash flooding of creeks and streams,
urban areas, highways, streets and underpasses.
Some locations that will experience flash flooding include...
mainly rural areas of Maricopa County
Eagle Eye Road along Tiger Wash between US 60 and Interstate 10.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.
In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.
&&
LAT...LON 3384 11333 3388 11319 3381 11309 3373 11311
3358 11326 3354 11322 3347 11313 3339 11308
3337 11311 3351 11333 3380 11333 3381 11333
3383 11333
FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
$$
Iniguez843
WGUS75 KPSR 011258
FFSPSR
Flash Flood Statement
National Weather Service Phoenix AZ
558 AM MST Wed Sep 1 2021
AZC013-011308-
/O.EXP.KPSR.FF.W.0240.000000T0000Z-210901T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
558 AM MST Wed Sep 1 2021
...FLASH FLOOD WARNING WILL EXPIRE AT 6 AM MST EARLY THIS MORNING
FOR MARICOPA COUNTY...
Flood waters have receded. Flooding is no longer expected to pose a
threat. Please continue to heed remaining road closures.
A Flash Flood Watch remains in effect until 500 AM MST Thursday for
portions of south central Arizona and southwest Arizona.
LAT...LON 3384 11333 3388 11319 3381 11309 3373 11311
3358 11326 3354 11322 3347 11313 3339 11308
3337 11311 3351 11333 3380 11333 3381 11333
3383 11333
$$
IniguezThe office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 31, 10:36 PM MST | Flash Flood Warning | PSR | La Paz | 6 hr |
| Sep 1, 12:02 AM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Sep 1, 6:44 AM MST | Areal Flood Warning | PSR | Gila | 5 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.