Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 99, NWS Flagstaff, AZ

August 13, 2021Yavapai County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 13, 2021, 5:41 PM MST for Yavapai County, Arizona. It was in force for 21 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 13, 2021, 5:41 PM MST (00:41 UTC)
Expired: Aug 13, 2021, 6:02 PM MST
In force: 21 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

County Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 162 km from the middle of the area, began a volume at 00:44 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.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 0.7 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: 430 J/kg
Mixed-layer CIN: -94 J/kg
Mixed-layer LCL: 1694 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: 170 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

984 
WUUS55 KFGZ 140041
SVRFGZ
AZC025-140115-
/O.NEW.KFGZ.SV.W.0099.210814T0041Z-210814T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
541 PM MST Fri Aug 13 2021

The National Weather Service in Flagstaff has issued a

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

* Until 615 PM MST.

* At 540 PM MST, a severe thunderstorm was located 14 miles south of
  Seligman, moving southwest at 20 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* This severe thunderstorm will remain over mainly rural areas of
  Yavapai County about 15 miles south of Seligman.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3519 11280 3515 11274 3497 11290 3508 11302
TIME...MOT...LOC 0040Z 046DEG 19KT 3512 11284 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

McCollum

1 follow-up statement

659 
WWUS55 KFGZ 140102
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
602 PM MST Fri Aug 13 2021

AZC025-140111-
/O.CAN.KFGZ.SV.W.0099.000000T0000Z-210814T0115Z/
Yavapai-
602 PM MST Fri Aug 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR YAVAPAI COUNTY IS CANCELLED...
                
The storm 15 miles south of Seligman which prompted the warning has 
weakened below severe limits, and no longer poses an immediate 
threat to life or property. Therefore, the warning has been 
cancelled.

LAT...LON 3519 11280 3515 11274 3497 11290 3508 11302
TIME...MOT...LOC 0059Z 046DEG 19KT 3504 11294 

$$


McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 13, 6:09 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	25 min
Aug 13, 6:18 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	27 min
Aug 13, 7:00 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	15 min
Aug 13, 7:39 PM MST	Severe Thunderstorm Warning	FGZ	Gila	26 min
Aug 13, 8:09 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	36 min
Aug 13, 8:15 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila, Yavapai	2 hr
Aug 13, 8:38 PM MST	Severe Thunderstorm Warning	FGZ	Gila, Yavapai	52 min
Aug 13, 9:03 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	42 min
Aug 13, 9:43 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	47 min
Aug 13, 9:51 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Aug 13, 10:07 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	53 min
Aug 14, 3:06 PM MST	Severe Thunderstorm Warning	FGZ	Gila	39 min
Aug 14, 3:42 PM MST	Severe Thunderstorm Warning	FGZ	Gila, Navajo	36 min
Aug 14, 3:58 PM MST	Severe Thunderstorm Warning	FGZ	Gila	29 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.