Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 17, NWS Phoenix, AZ

July 10, 2021Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 10, 2021, 6:42 PM MST for Maricopa County, Arizona. It was in force for 33 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 10, 2021, 6:42 PM MST (01:42 UTC)
Expired
Jul 10, 2021, 7:15 PM MST
In force
33 min
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Hail
1.0 in
Wind
70.0 mph

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 74 km from the middle of the area, began a volume at 01:44 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.

What was reported inside it

TimeReportWhereRemark
Jul 10, 6:50 PM MSTTSTM WND GST 8316 Ne Carefree, AZCORRECTS PREVIOUS TSTM WND GST REPORT FROM 5 NNE TORTILLA FLAT. SRP MESONET STATION AT HORSESHOE DAM.
Jul 10, 6:55 PM MSTTSTM WND GST 6816 Wnw Sunflower, AZMESONET STATION SRP19 16.2 NE CAREFREE (SRP).

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

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

IssuedProductOfficeLasted
Jul 10, 4:52 PM MSTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 1.7 hours before the alert went out and 58 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 2021-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 965 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 2021-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 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
965 J/kg
Mixed-layer CIN
-311 J/kg
Mixed-layer LCL
3378 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

384 
WUUS55 KPSR 110142
SVRPSR
AZC013-110215-
/O.NEW.KPSR.SV.W.0017.210711T0142Z-210711T0215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Phoenix AZ
642 PM MST Sat Jul 10 2021

The National Weather Service in Phoenix has issued a

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

* Until 715 PM MST.

* At 641 PM MST, a severe thunderstorm was located near Horseshoe
  Reservoir, or 16 miles northwest of Sycamore Creek, moving
  southwest at 25 mph.

  HAZARD...70 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect considerable 
           tree damage. Wind damage is also likely to mobile homes, 
           roofs, and outbuildings.

* Locations impacted include...
  Scottsdale, New River, Cave Creek, Carefree, McDowell Mountain
  Park, Desert Mountain, Camp Creek, Rio Verde, Horseshoe Reservoir
  and Seven Springs.

* This includes AZ Interstate 17 between mile markers 234 and 241.
 
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 3401 11176 3400 11148 3365 11169 3394 11216
      3404 11216
TIME...MOT...LOC 0141Z 037DEG 23KT 3408 11170 

HAIL...1.00IN
WIND...70MPH
 
$$

SDB

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 10, 5:37 PM MSTSpecial Weather StatementPSRGila38 min
Jul 10, 5:45 PM MSTSevere Thunderstorm WarningPSRGila45 min
Jul 10, 6:06 PM MSTSpecial Weather StatementPSRGila39 min
Jul 10, 6:24 PM MSTSevere Thunderstorm WarningPSRGila, Maricopa, Pinal36 min
Jul 10, 7:00 PM MSTSevere Thunderstorm WarningPSRGila, Maricopa, Pinal45 min
Jul 10, 7:10 PM MSTFlash Flood Warning Considerable damage threatPSRGila4 hr
Jul 10, 7:12 PM MSTSevere Thunderstorm WarningPSRMaricopa33 min
Jul 10, 7:27 PM MSTDust Storm WarningPSRMaricopa63 min
Jul 10, 7:31 PM MSTDust Storm WarningPSRMaricopa, Pinal59 min
Jul 10, 7:45 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal30 min
Jul 10, 8:16 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal44 min
Jul 10, 8:29 PM MSTDust Storm WarningPSRMaricopa, Pinal91 min
Jul 10, 8:42 PM MSTAreal Flood AdvisoryPSRMaricopa, Pinal3 hr
Jul 10, 9:00 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal45 min
Jul 10, 9:48 PM MSTSpecial Weather StatementPSR57 min
Jul 10, 9:54 PM MSTSpecial Weather StatementPSRPinal36 min
Jul 10, 10:25 PM MSTSpecial Weather StatementPSR35 min
Jul 10, 10:31 PM MSTDust Storm AdvisoryPSRMaricopa, Yuma89 min
Jul 10, 10:43 PM MSTDust Storm WarningPSRMaricopa, Yuma62 min
Jul 10, 11:19 PM MSTDust Storm WarningPSRYuma56 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.