Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 97, NWS Flagstaff, AZ

August 10, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 10, 2021, 2:35 PM MST for Yavapai County, Arizona. It was in force for 40 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 10, 2021, 2:35 PM MST (21:35 UTC)
Expired: Aug 10, 2021, 3:15 PM MST
In force: 40 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), 118 km from the middle of the area, began a volume at 21:39 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

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 9.6 hours before the alert went out and 101 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: 609 J/kg
Mixed-layer CIN: -55 J/kg
Mixed-layer LCL: 962 m above ground
0-6 km bulk shear: 5 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 118 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

132 
WUUS55 KFGZ 102135
SVRFGZ
AZC025-102215-
/O.NEW.KFGZ.SV.W.0097.210810T2135Z-210810T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
235 PM MST Tue Aug 10 2021

The National Weather Service in Flagstaff has issued a

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

* Until 315 PM MST.

* At 234 PM MST, a severe thunderstorm was located over Indian Hill
  West Prescott, or near Prescott Valley, and is nearly stationary.

  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, Walker, Iron 
  Springs, Yavapai Campground, 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.

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

&&

LAT...LON 3445 11260 3465 11257 3463 11231 3438 11234
TIME...MOT...LOC 2134Z 269DEG 0KT 3452 11247 

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

$$

Humphreys

2 follow-up statements

220 
WWUS55 KFGZ 102201
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
301 PM MST Tue Aug 10 2021

AZC025-102215-
/O.CON.KFGZ.SV.W.0097.000000T0000Z-210810T2215Z/
Yavapai-
301 PM MST Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 315 PM MST
FOR YAVAPAI COUNTY...

At 301 PM MST, a severe thunderstorm was located over Downtown
Prescott, or near Prescott Valley, and is nearly stationary.

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, Walker, Iron 
Springs, Yavapai Campground, 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.

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

&&

LAT...LON 3453 11258 3465 11257 3461 11233 3441 11239
TIME...MOT...LOC 2201Z 269DEG 0KT 3452 11247 

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

$$

Humphreys

537 
WWUS55 KFGZ 102209
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
309 PM MST Tue Aug 10 2021

AZC025-102219-
/O.EXP.KFGZ.SV.W.0097.000000T0000Z-210810T2215Z/
Yavapai-
309 PM MST Tue Aug 10 2021

...THE SEVERE THUNDERSTORM WARNING NEAR PRESCOTT IN
YAVAPAI COUNTY WILL EXPIRE AT
315 PM MST...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However heavy rain
is still possible with this thunderstorm.

LAT...LON 3453 11258 3465 11257 3461 11233 3441 11239
TIME...MOT...LOC 2209Z 269DEG 0KT 3452 11247 

$$

Humphreys

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 5:19 PM MST	Special Weather Statement	FGZ		41 min
Aug 9, 6:17 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Aug 9, 6:56 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	34 min
Aug 9, 7:27 PM MST	Special Weather Statement	FGZ		33 min
Aug 9, 7:50 PM MST	Special Weather Statement	FGZ	Gila	25 min
Aug 9, 8:44 PM MST	Special Weather Statement	FGZ	Gila	46 min
Aug 9, 9:18 PM MST	Areal Flood Advisory	FGZ	Gila, Navajo	3 hr
Aug 9, 9:32 PM MST	Special Weather Statement	FGZ	Gila	43 min
Aug 10, 11:35 AM MST	Special Weather Statement	FGZ		25 min
Aug 10, 11:55 AM MST	Severe Thunderstorm Warning	FGZ	Coconino	15 min
Aug 10, 12:02 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Aug 10, 12:14 PM MST	Special Weather Statement	FGZ		31 min
Aug 10, 12:46 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Aug 10, 12:59 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Yavapai	3 hr
Aug 10, 1:22 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Yavapai	53 min
Aug 10, 2:22 PM MST	Special Weather Statement	FGZ	Yavapai	23 min
Aug 10, 2:26 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	32 min
Aug 10, 2:43 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Aug 10, 2:52 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Yavapai	38 min
Aug 10, 3:11 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Yavapai	3 hr
Aug 10, 3:46 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Aug 10, 4:13 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.