Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 91, NWS Phoenix, AZ

August 16, 2021Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 16, 2021, 11:52 PM MST for Maricopa County, Arizona. It was in force for 38 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 16, 2021, 11:52 PM MST (06:52 UTC)
Expired
Aug 17, 2021, 12:30 AM MST
In force
38 min
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 66 km from the middle of the area, began a volume at 06:51 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Aug 16, 3:54 PM MSTSevere Thunderstorm WatchSPC10 hr

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 6.9 hours before the alert went out and 42 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-pSkew-T log-p diagram, Phoenix, AZ at 00:00Z on 2021-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2667 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 00:00Z on 2021-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 24 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
2667 J/kg
Mixed-layer CIN
-7 J/kg
Mixed-layer LCL
1942 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
24 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

The text

As transmitted.

920 
WUUS55 KPSR 170652
SVRPSR
AZC013-170730-
/O.NEW.KPSR.SV.W.0091.210817T0652Z-210817T0730Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Phoenix AZ
1152 PM MST Mon Aug 16 2021

The National Weather Service in Phoenix has issued a

* Severe Thunderstorm Warning for...
  Maricopa County in south central Arizona...

* Until 1230 AM MST.

* At 1151 PM MST, a severe thunderstorm was located near Cave Creek,
  or 10 miles southeast of New River, moving southwest at 10 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Phoenix, Scottsdale, New River, Cave Creek, Carefree, Deer Valley
  Airport and Anthem.

This includes the following highways...
AZ Interstate 17 between mile markers 218 and 227.
AZ Route 74 between mile markers 28 and 30.
AZ Route 303 between mile markers 137 and 139.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

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

&&

LAT...LON 3391 11198 3377 11185 3367 11204 3371 11214
      3383 11220
TIME...MOT...LOC 0651Z 053DEG 8KT 3379 11202 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

SDB
1 follow-up statement
350 
WWUS55 KPSR 170716
SVSPSR

Severe Weather Statement
National Weather Service Phoenix AZ
1216 AM MST Tue Aug 17 2021

AZC013-170730-
/O.CON.KPSR.SV.W.0091.000000T0000Z-210817T0730Z/
Maricopa AZ-
1216 AM MST Tue Aug 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1230 AM MST
FOR MARICOPA COUNTY...

At 1216 AM MST, a severe thunderstorm was located near Deer Valley
Airport, or 10 miles northeast of Peoria, moving southwest at 10 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Phoenix, New River, Cave Creek, Deer Valley Airport and Anthem. 

This includes the following highways...
AZ Interstate 17 between mile markers 218 and 227.
AZ Route 74 between mile markers 28 and 30.
AZ Route 303 between mile markers 137 and 139.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 3389 11204 3371 11196 3367 11204 3371 11214
      3383 11220
TIME...MOT...LOC 0716Z 053DEG 8KT 3376 11207 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

SDB

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 5:15 PM MSTSpecial Weather StatementPSRGila45 min
Aug 16, 5:46 PM MSTSpecial Weather StatementPSR44 min
Aug 16, 6:07 PM MSTSpecial Weather StatementPSRGila38 min
Aug 16, 6:14 PM MSTSevere Thunderstorm WarningPSRGila46 min
Aug 16, 6:37 PM MSTSpecial Weather StatementPSRPinal53 min
Aug 16, 6:55 PM MSTFlash Flood Warning Considerable damage threatPSRGila6 hr
Aug 16, 8:24 PM MSTSpecial Weather StatementPSR51 min
Aug 16, 8:41 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa5 hr
Aug 16, 8:53 PM MSTSpecial Weather StatementPSRGila52 min
Aug 16, 9:08 PM MSTSpecial Weather StatementPSRGila52 min
Aug 16, 9:22 PM MSTSevere Thunderstorm WarningPSRGila, Maricopa, Pinal38 min
Aug 16, 9:41 PM MSTSevere Thunderstorm WarningPSRGila, Maricopa, Pinal49 min
Aug 16, 9:49 PM MSTSevere Thunderstorm Warning Considerable damage threatPSRGila, Maricopa41 min
Aug 16, 10:01 PM MSTFlash Flood Warning Considerable damage threatPSRGila4 hr
Aug 16, 10:01 PM MSTSpecial Weather StatementPSR44 min
Aug 16, 10:05 PM MSTFlash Flood Warning Considerable damage threatPSRGila4 hr
Aug 16, 10:14 PM MSTSevere Thunderstorm Warning Considerable damage threatPSRGila, Maricopa, Pinal46 min
Aug 16, 10:22 PM MSTFlash Flood Warning Considerable damage threatPSRGila10 hr
Aug 16, 10:28 PM MSTFlash Flood Warning Considerable damage threatPSRGila, Maricopa, Pinal10 hr
Aug 16, 10:36 PM MSTFlash Flood Warning Considerable damage threatPSRGila, Maricopa10 hr
Aug 16, 10:38 PM MSTDust Storm AdvisoryPSRMaricopa, Pinal67 min
Aug 16, 10:48 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa, Pinal9 hr
Aug 16, 10:54 PM MSTSevere Thunderstorm Warning Destructive damage threatPSRMaricopa, Pinal51 min
Aug 16, 10:58 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa7 hr
Aug 16, 11:04 PM MSTDust Storm WarningPSRMaricopa, Pinal56 min
Aug 16, 11:07 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa, Pinal7 hr
Aug 16, 11:16 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa7 hr
Aug 16, 11:26 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa, Pinal8 hr
Aug 16, 11:31 PM MSTSevere Thunderstorm WarningPSRMaricopa44 min
Aug 16, 11:41 PM MSTSevere Thunderstorm Warning Considerable damage threatPSRMaricopa, Pinal49 min
Aug 16, 11:47 PM MSTDust Storm WarningPSRMaricopa58 min
Aug 16, 11:50 PM MSTSpecial Weather StatementPSR40 min
Aug 16, 11:56 PM MSTFlash Flood Warning Considerable damage threatPSRPinal7 hr
Aug 16, 11:59 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa6 hr
Aug 17, 12:01 AM MSTDust Storm WarningPSRMaricopa, Pinal59 min
Aug 17, 12:09 AM MSTFlash Flood Warning Considerable damage threatPSRMaricopa, Pinal8 hr
Aug 17, 12:32 AM MSTSpecial Weather StatementPSR43 min
Aug 17, 12:36 AM MSTSpecial Weather StatementPSRMaricopa24 min
Aug 17, 4:05 AM MSTAreal Flood AdvisoryPSRMaricopa4 hr
Aug 17, 4:26 AM MSTFlash Flood Warning Considerable damage threatPSRMaricopa6 hr
Aug 17, 5:29 AM MSTSpecial Weather StatementPSRMaricopa76 min
Aug 17, 5:35 AM MSTFlash Flood Warning Considerable damage threatPSRMaricopa6 hr
Aug 17, 6:26 AM MSTFlash Flood Warning Considerable damage threatPSRGila, Pinal5 hr
Aug 17, 8:42 AM MSTAreal Flood WarningPSRGila5 days
Aug 17, 4:46 PM MSTSpecial Weather StatementPSR44 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2021Every severe thunderstorm 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.