Alert archive / Arizona / Flash Flood Warnings in 2023

Flash Flood Warning 28, NWS Phoenix, AZ

September 2, 2023La Paz County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Sep 2, 2023, 12:16 PM MST for La Paz County, Arizona. It was in force for 7 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 2, 2023, 12:16 PM MST (19:16 UTC)
Expired: Sep 2, 2023, 6:54 PM MST
In force: 7 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County La Paz County, AZ

The radar

The Yuma radar (KYUX), 151 km from the middle of the area, began a volume at 19:18 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

Phoenix, AZ (KPSR), launched 12:00Z, 7.3 hours before the alert went out and 189 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2443 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 1 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 2, 10:00 AM MST, 2 hours 16 minutes earlier.

Area forecast discussion, Sep 2, 10:00 AM MST, 2 hours 16 minutes before

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In the hours before

Special weather statement, Sep 2, 11:42 AM MST, 34 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
1142 AM MST Sat Sep 2 2023

AZZ530-533-021930-
Parker Valley AZ-Central La Paz AZ-
1142 AM MST Sat Sep 2 2023

...A strong thunderstorm will impact portions of north central La Paz
County through 1230 PM MST...

At 1141 AM MST, Doppler radar was tracking a strong thunderstorm near
Bouse, or 17 miles southeast of Parker, moving north at 15 mph.

HAZARD...Winds in excess of 40 mph and heavy rainfall.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Bouse.

This includes AZ Route 72 between mile markers 15 and 27.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3386 11402 3387 11418 3415 11422 3419 11395
TIME...MOT...LOC 1841Z 178DEG 14KT 3392 11411

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

TF

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 1, 7:32 PM MST	Areal Flood Warning	PSR	La Paz	3 hr
Sep 2, 2:54 AM MST	Areal Flood Advisory	PSR	Yuma	111 min
Sep 2, 3:05 AM MST	Special Weather Statement	PSR		40 min
Sep 2, 11:42 AM MST	Special Weather Statement	PSR	La Paz	48 min
Sep 2, 12:32 PM MST	Special Weather Statement	PSR	La Paz, Yuma	3 hr
Sep 2, 12:43 PM MST	Flash Flood Warning Considerable damage threat	PSR	Yuma	3 hr
Sep 2, 2:24 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	4 hr
Sep 2, 2:34 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	4 hr
Sep 2, 2:46 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	4 hr
Sep 2, 2:48 PM MST	Areal Flood Advisory	PSR	Yuma	3 hr
Sep 2, 3:27 PM MST	Flash Flood Warning Considerable damage threat	PSR	Yuma	5 hr
Sep 2, 3:34 PM MST	Special Weather Statement	PSR	La Paz	86 min
Sep 2, 3:46 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz, Yuma	3 hr
Sep 2, 4:36 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz, Maricopa	5 hr
Sep 2, 4:46 PM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Sep 1, 5:52 PM MST	Areal Flood Warning	PSR	Imperial	5 hr
Sep 1, 8:29 PM MST	Areal Flood Warning	PSR	Riverside, San Bernardino	2 hr
Sep 1, 9:15 PM MST	Areal Flood Warning	PSR	Imperial, Riverside, San Bernardino	2 hr
Sep 2, 1:42 PM MST	Flash Flood Warning Considerable damage threat	PSR	Riverside	3 hr

Nearby

Flash Flood Warnings in Arizona, 2023 Every flash flood warning in 2023

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.