Alert archive / Arizona / Flash Flood Warnings in 2022

Flash Flood Warning 290, NWS Phoenix, AZ

September 21, 2022Maricopa County, Yuma County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Sep 21, 2022, 5:41 PM MST for Maricopa County, Yuma 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 counties it named.

The facts

Issued: Sep 21, 2022, 5:41 PM MST (00:41 UTC)
Expired: Sep 21, 2022, 9:09 PM MST
In force: 3 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Maricopa County, AZ, Yuma County, AZ

The radar

The Phoenix radar (KIWA), 145 km from the middle of the area, began a volume at 00:40 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

Tuscon, AZ (KTUS), launched 00:00Z, 0.7 hours before the alert went out and 237 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1176 J/kg
Mixed-layer CIN: -42 J/kg
Mixed-layer LCL: 1004 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 6 m²/s²
0-3 km storm-relative helicity: 50 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.6

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Phoenix, AZ wrote its last area forecast discussion before this flash flood warning went out at Sep 21, 4:40 PM MST, 1 hour 1 minute earlier.

Area forecast discussion, Sep 21, 4:40 PM MST, 1 hour 1 minute before

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In the hours before

Local storm report, Sep 21, 3:26 PM MST, 2 hours 15 minutes before

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Special weather statement, Sep 21, 4:48 PM MST, 53 minutes before

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Special weather statement, Sep 21, 4:52 PM MST, 49 minutes before

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Special weather statement, Sep 21, 5:24 PM MST, 17 minutes before

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Special weather statement, Sep 21, 5:32 PM MST, 9 minutes before

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Special weather statement, Sep 21, 5:34 PM MST, 7 minutes before

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The office that day

Everything else NWS Phoenix, AZ issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 21, 5:16 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	3 hr
Sep 21, 5:24 PM MST	Special Weather Statement	PSR		66 min
Sep 21, 5:32 PM MST	Special Weather Statement	PSR	Yuma	43 min
Sep 21, 5:34 PM MST	Special Weather Statement	PSR		56 min
Sep 21, 6:01 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz, Yuma	3 hr
Sep 21, 6:12 PM MST	Special Weather Statement	PSR	La Paz	63 min
Sep 21, 7:04 PM MST	Special Weather Statement	PSR	La Paz	56 min
Sep 21, 8:18 PM MST	Special Weather Statement	PSR	La Paz	57 min
Sep 21, 9:05 PM MST	Areal Flood Warning	PSR	Maricopa, Pinal	11 hr
Sep 22, 10:19 AM MST	Special Weather Statement	PSR	Gila	26 min
Sep 22, 12:26 PM MST	Special Weather Statement	PSR	La Paz	49 min
Sep 22, 12:28 PM MST	Special Weather Statement	PSR		47 min
Sep 22, 1:17 PM MST	Special Weather Statement	PSR	Gila	43 min
Sep 22, 1:22 PM MST	Special Weather Statement	PSR	La Paz	53 min
Sep 22, 1:27 PM MST	Special Weather Statement	PSR	Maricopa	48 min
Sep 22, 1:58 PM MST	Special Weather Statement	PSR	Gila	47 min
Sep 22, 2:10 PM MST	Special Weather Statement	PSR		50 min
Sep 22, 2:17 PM MST	Special Weather Statement	PSR	La Paz	43 min
Sep 22, 2:25 PM MST	Areal Flood Advisory	PSR	La Paz	2 hr
Sep 22, 3:02 PM MST	Areal Flood Advisory	PSR	Maricopa	23 min
Sep 22, 3:25 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	3 hr
Sep 22, 3:58 PM MST	Areal Flood Advisory	PSR	La Paz	3 hr
Sep 22, 4:57 PM MST	Areal Flood Advisory	PSR	La Paz	4 hr

Nearby

Flash Flood Warnings in Arizona, 2022 Every flash flood warning in 2022

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.