Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 79, NWS Phoenix, AZ

August 15, 2021Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 15, 2021, 11:37 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 15, 2021, 11:37 PM MST (06:37 UTC)
Expired
Aug 16, 2021, 12:15 AM MST
In force
38 min
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Hail
0.88 in
Wind
60.0 mph

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 45 km from the middle of the area, began a volume at 06:38 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 00:00Z, 6.6 hours before the alert went out and 15 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 2021-08-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1548 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 2021-08-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -22 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
1548 J/kg
Mixed-layer CIN
-94 J/kg
Mixed-layer LCL
2123 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-22 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

290 
WUUS55 KPSR 160637
SVRPSR
AZC013-160715-
/O.NEW.KPSR.SV.W.0079.210816T0637Z-210816T0715Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Phoenix AZ
1137 PM MST Sun Aug 15 2021

The National Weather Service in Phoenix has issued a

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

* Until 1215 AM MST.

* At 1137 PM MST, a severe thunderstorm was located over Piestewa
  Peak Park, or over Paradise Valley, moving southwest at 10 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Phoenix, Glendale, Scottsdale, Tempe, Paradise Valley, Papago Park,
  Piestewa Peak Park, North Mountain Park, Arizona State Fairgrounds,
  Downtown Phoenix, Downtown Scottsdale, Metro Center Mall, Camelback
  Mountain, Sky Harbor Airport and Downtown Glendale.

This includes the following highways...
AZ Interstate 10 between mile markers 139 and 155.
AZ Interstate 17 between mile markers 195 and 211.
AZ Route 51 between mile markers 1 and 14.

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 3366 11200 3357 11184 3335 11199 3349 11223
      3360 11215
TIME...MOT...LOC 0637Z 036DEG 11KT 3352 11200 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.88 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

SDB
1 follow-up statement
025 
WWUS55 KPSR 160706
SVSPSR

Severe Weather Statement
National Weather Service Phoenix AZ
1206 AM MST Mon Aug 16 2021

AZC013-160716-
/O.EXP.KPSR.SV.W.0079.000000T0000Z-210816T0715Z/
Maricopa AZ-
1206 AM MST Mon Aug 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR MARICOPA COUNTY WILL EXPIRE AT
1215 AM MST...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.  However gusty winds are still possible with
this thunderstorm.

LAT...LON 3366 11200 3357 11184 3335 11199 3349 11223
      3360 11215
TIME...MOT...LOC 0706Z 036DEG 11KT 3346 11205 

$$

SDB

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 15, 7:49 PM MSTSpecial Weather StatementPSRGila56 min
Aug 15, 8:26 PM MSTSevere Thunderstorm WarningPSRGila49 min
Aug 15, 9:14 PM MSTSevere Thunderstorm WarningPSRGila, Maricopa, Pinal46 min
Aug 15, 9:18 PM MSTSpecial Weather StatementPSRGila42 min
Aug 15, 9:58 PM MSTSevere Thunderstorm Warning Considerable damage threatPSRGila, Maricopa, Pinal47 min
Aug 15, 10:14 PM MSTFlash Flood Warning Considerable damage threatPSRGila4 hr
Aug 15, 10:31 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal44 min
Aug 15, 10:45 PM MSTSpecial Weather StatementPSRPinal45 min
Aug 15, 10:50 PM MSTFlash Flood Warning Considerable damage threatPSRGila, Maricopa, Pinal6 hr
Aug 15, 10:55 PM MSTDust Storm AdvisoryPSRMaricopa, Pinal65 min
Aug 15, 10:58 PM MSTAreal Flood AdvisoryPSRMaricopa, Pinal3 hr
Aug 15, 11:14 PM MSTSevere Thunderstorm WarningPSRMaricopa46 min
Aug 15, 11:31 PM MSTSpecial Weather StatementPSRMaricopa44 min
Aug 15, 11:44 PM MSTSevere Thunderstorm WarningPSRMaricopa32 min
Aug 15, 11:45 PM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Aug 16, 12:18 AM MSTSpecial Weather StatementPSR42 min
Aug 16, 12:49 AM MSTSevere Thunderstorm WarningPSRLa Paz, Maricopa56 min
Aug 16, 1:33 AM MSTFlash Flood Warning Considerable damage threatPSRLa Paz, Maricopa6 hr
Aug 16, 1:47 AM MSTSpecial Weather StatementPSRLa Paz58 min
Aug 16, 1:54 AM MSTSevere Thunderstorm WarningPSRLa Paz66 min
Aug 16, 2:22 AM MSTSpecial Weather StatementPSRLa Paz68 min
Aug 16, 2:53 AM MSTFlash Flood Warning Considerable damage threatPSRLa Paz5 hr
Aug 16, 3:08 AM MSTDust Storm AdvisoryPSRLa Paz, Yuma2 hr

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.