Alert archive / Arizona / Severe Thunderstorm Warnings in 2025

Severe Thunderstorm Warning 66, NWS Phoenix, AZ

September 17, 2025Yuma County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Sep 17, 2025, 5:59 PM MST for Yuma County, Arizona. It was in force for 46 min. 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 17, 2025, 5:59 PM MST (00:59 UTC)
Expired: Sep 17, 2025, 6:45 PM MST
In force: 46 min
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Yuma County, AZ

The radar

The Yuma radar (KYUX), 77 km from the middle of the area, began a volume at 01:02 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, 1.0 hours before the alert went out and 290 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: 239 J/kg
Mixed-layer CIN: -100 J/kg
Mixed-layer LCL: 2270 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 51 m²/s²
0-3 km storm-relative helicity: 68 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 severe thunderstorm 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 severe thunderstorm warning went out at Sep 17, 4:40 PM MST, 1 hour 19 minutes earlier.

Area forecast discussion, Sep 17, 4:40 PM MST, 1 hour 19 minutes before

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In the hours before

Special weather statement, Sep 17, 2:06 PM MST, 3 hours 53 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
206 PM PDT Wed Sep 17 2025

CAZ564-570-172130-
Chuckwalla Mountains CA-Chuckwalla Valley CA-
206 PM PDT Wed Sep 17 2025

...A STRONG THUNDERSTORM WILL IMPACT RIVERSIDE COUNTY THROUGH 230 PM
PDT...

At 206 PM PDT, Doppler radar was tracking a strong thunderstorm 14
miles south of Desert Center. This thunderstorm was nearly
stationary.

HAZARD...Wind gusts up to 50 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This storm will remain over mainly rural areas of Riverside County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3364 11520 3343 11523 3343 11546 3362 11552
      3364 11551
TIME...MOT...LOC 2106Z 180DEG 2KT 3351 11534

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

TW

Special weather statement, Sep 17, 2:15 PM MST, 3 hours 44 minutes before

Special Weather Statement
National Weather Service Phoenix AZ
215 PM PDT Wed Sep 17 2025

CAZ564-568-172145-
Chuckwalla Mountains CA-Chiriaco Summit CA-
215 PM PDT Wed Sep 17 2025

...A STRONG THUNDERSTORM WILL IMPACT RIVERSIDE COUNTY THROUGH 245 PM
PDT...

At 215 PM PDT, Doppler radar was tracking a strong thunderstorm 10
miles southeast of Chiriaco Summit. This thunderstorm was nearly
stationary.

HAZARD...Wind gusts up to 50 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

This storm will remain over mainly rural areas of Riverside County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3346 11548 3346 11572 3365 11575 3366 11547
TIME...MOT...LOC 2115Z 176DEG 1KT 3355 11560

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

TW

Special weather statement, Sep 17, 4:33 PM MST, 1 hour 26 minutes before

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Special weather statement, Sep 17, 4:51 PM MST, 1 hour 8 minutes before

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Special weather statement, Sep 17, 5:14 PM MST, 45 minutes before

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Special weather statement, Sep 17, 5:33 PM MST, 26 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 17, 5:33 PM MST	Special Weather Statement	PSR	Yuma	42 min
Sep 17, 5:39 PM MST	Areal Flood Advisory	PSR	Yuma	3 hr
Sep 18, 11:25 AM MST	Special Weather Statement	PSR	La Paz	35 min
Sep 18, 11:29 AM MST	Special Weather Statement	PSR	La Paz	31 min
Sep 18, 11:45 AM MST	Severe Thunderstorm Warning	PSR	La Paz	45 min
Sep 18, 12:18 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz, Yuma	7 hr
Sep 18, 12:29 PM MST	Severe Thunderstorm Warning	PSR	La Paz	46 min
Sep 18, 12:35 PM MST	Severe Thunderstorm Warning	PSR	La Paz	55 min
Sep 18, 12:36 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	7 hr
Sep 18, 12:45 PM MST	Special Weather Statement	PSR		75 min
Sep 18, 12:48 PM MST	Severe Thunderstorm Warning	PSR	La Paz	57 min
Sep 18, 1:08 PM MST	Areal Flood Advisory	PSR	La Paz	3 hr
Sep 18, 1:10 PM MST	Severe Thunderstorm Warning	PSR	La Paz	50 min
Sep 18, 1:16 PM MST	Severe Thunderstorm Warning	PSR	La Paz	47 min
Sep 18, 1:20 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	6 hr
Sep 18, 1:32 PM MST	Special Weather Statement	PSR	Maricopa	43 min
Sep 18, 1:44 PM MST	Areal Flood Advisory	PSR	La Paz, Yuma	74 min
Sep 18, 1:48 PM MST	Severe Thunderstorm Warning	PSR	La Paz	42 min
Sep 18, 1:51 PM MST	Special Weather Statement	PSR	Gila	39 min
Sep 18, 1:52 PM MST	Areal Flood Advisory	PSR	Gila	3 hr
Sep 18, 2:18 PM MST	Severe Thunderstorm Warning	PSR	La Paz, Maricopa	42 min
Sep 18, 2:29 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	3 hr
Sep 18, 2:44 PM MST	Special Weather Statement	PSR	Gila	46 min
Sep 18, 2:54 PM MST	Special Weather Statement	PSR		51 min
Sep 18, 2:55 PM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Sep 18, 2:58 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz, Yuma	3 hr
Sep 18, 3:20 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila, Maricopa	3 hr
Sep 18, 3:21 PM MST	Special Weather Statement	PSR		39 min
Sep 18, 3:24 PM MST	Special Weather Statement	PSR	Gila	36 min
Sep 18, 3:29 PM MST	Severe Thunderstorm Warning	PSR	Gila, Maricopa	31 min
Sep 18, 4:09 PM MST	Areal Flood Advisory	PSR	Gila	3 hr
Sep 18, 4:59 PM MST	Special Weather Statement	PSR	Yuma	46 min
Sep 17, 5:14 PM MST	Special Weather Statement	PSR	Imperial	46 min
Sep 18, 1:39 AM MST	Areal Flood Advisory	PSR	Imperial	111 min
Sep 18, 5:14 AM MST	Areal Flood Advisory	PSR	Riverside	2 hr
Sep 18, 4:55 PM MST	Special Weather Statement	PSR	Imperial	50 min
Sep 18, 4:56 PM MST	Flash Flood Warning Considerable damage threat	PSR	Imperial	3 hr

Nearby

Severe Thunderstorm Warnings in Arizona, 2025 Every severe thunderstorm warning in 2025

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.