Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 11, NWS Flagstaff, AZ

July 9, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 9, 2021, 3:33 PM MST for Yavapai County, Arizona. It was in force for 27 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 9, 2021, 3:33 PM MST (22:33 UTC)
Expired: Jul 9, 2021, 4:00 PM MST
In force: 27 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 116 km from the middle of the area, began a volume at 22:34 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

Time	Report	Where	Remark
Jul 9, 3:38 PM MST	HAIL 0.5	5 Sw Prescott Valley, AZ
Jul 9, 3:40 PM MST	HAIL 0.7	1 Ne Prescott Courthous, AZ

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

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 10.6 hours before the alert went out and 96 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: 115 J/kg
Mixed-layer CIN: -284 J/kg
Mixed-layer LCL: 2249 m above ground
0-6 km bulk shear: 5 kt
0-1 km storm-relative helicity: 74 m²/s²
0-3 km storm-relative helicity: 130 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

770 
WUUS55 KFGZ 092233
SVRFGZ
AZC025-092300-
/O.NEW.KFGZ.SV.W.0011.210709T2233Z-210709T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
333 PM MST Fri Jul 9 2021

The National Weather Service in Flagstaff has issued a

* Severe Thunderstorm Warning for...
  Yavapai County in west central Arizona...

* Until 400 PM MST.

* At 332 PM MST, a severe thunderstorm was located over Downtown
  Prescott, or near Prescott Valley, 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...
  Prescott Valley, Prescott, Groom Creek Subdivision, Prescott
  Gateway Mall, Iron Springs, Downtown Prescott, Ponderosa Park,
  Indian Hill West Prescott, Oak Knoll Village, Lower Wolf Creek
  Campground, Lynx Lake Dam, Upper Wolf Creek Group Campground and
  White Spar Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3465 11244 3453 11232 3440 11249 3456 11262
TIME...MOT...LOC 2232Z 051DEG 7KT 3455 11245 

HAIL...1.00IN
WIND...60MPH
 
$$
JJ

1 follow-up statement

992 
WWUS55 KFGZ 092302
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
402 PM MST Fri Jul 9 2021

AZC025-092311-
/O.EXP.KFGZ.SV.W.0011.000000T0000Z-210709T2300Z/
Yavapai-
402 PM MST Fri Jul 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR YAVAPAI COUNTY HAS EXPIRED...
                
The storm which prompted the warning has weakened below severe 
limits but is still producing heavy rainfall. A Flash Flood Warning 
is now in effect for this area until 7 PM MST.

LAT...LON 3465 11244 3453 11232 3440 11249 3456 11262
TIME...MOT...LOC 2301Z 051DEG 7KT 3452 11250 

$$
JJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 8, 5:13 PM MST	Special Weather Statement	FGZ	Yavapai	32 min
Jul 8, 5:28 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	19 min
Jul 8, 6:25 PM MST	Special Weather Statement	FGZ	Yavapai	50 min
Jul 8, 7:03 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 9, 3:02 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	28 min
Jul 9, 3:22 PM MST	Severe Thunderstorm Warning	FGZ	Gila	23 min
Jul 9, 3:42 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	48 min
Jul 9, 3:45 PM MST	Areal Flood Advisory	FGZ	Yavapai	2 hr
Jul 9, 3:59 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 9, 4:26 PM MST	Areal Flood Advisory	FGZ	Yavapai	2 hr
Jul 9, 4:48 PM MST	Severe Thunderstorm Warning	FGZ	Gila	42 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2021 Every 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.