Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 92, NWS Flagstaff, AZ

August 6, 2021Navajo County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 6, 2021, 2:01 PM MDT for Navajo County, Arizona. It was in force for 44 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 6, 2021, 2:01 PM MDT (20:01 UTC)
Expired: Aug 6, 2021, 2:45 PM MDT
In force: 44 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 95 km from the middle of the area, began a volume at 20:03 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, 8.0 hours before the alert went out and 174 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: 39 J/kg
Mixed-layer CIN: -179 J/kg
Mixed-layer LCL: 2177 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 58 m²/s²
0-3 km storm-relative helicity: 28 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

490 
WUUS55 KFGZ 062001
SVRFGZ
AZC017-062045-
/O.NEW.KFGZ.SV.W.0092.210806T2001Z-210806T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
101 PM MST Fri Aug 6 2021

The National Weather Service in Flagstaff has issued a

* Severe Thunderstorm Warning for...
  Navajo County in north central Arizona...

* Until 145 PM MST.

* At 100 PM MST, a severe thunderstorm was located near Taylor, or 15
  miles northwest of Show Low, 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...
  Taylor, Shumway and Snowflake. 

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 3436 11024 3447 11024 3450 11009 3436 11007
TIME...MOT...LOC 2000Z 256DEG 2KT 3442 11019 

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

$$

DB

1 follow-up statement

538 
WWUS55 KFGZ 062039
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
139 PM MST Fri Aug 6 2021

AZC017-062048-
/O.EXP.KFGZ.SV.W.0092.000000T0000Z-210806T2045Z/
Navajo-
139 PM MST Fri Aug 6 2021

...THE SEVERE THUNDERSTORM WARNING FOR NAVAJO COUNTY WILL EXPIRE AT
145 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 3436 11024 3447 11024 3450 11009 3436 11007
TIME...MOT...LOC 2038Z 256DEG 2KT 3442 11017 

$$

DB

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 6, 12:54 PM MDT	Special Weather Statement	FGZ		36 min
Aug 6, 1:26 PM MDT	Severe Thunderstorm Warning	FGZ	Apache, Navajo	30 min
Aug 6, 1:33 PM MDT	Areal Flood Advisory	FGZ	Navajo	2 hr
Aug 6, 2:18 PM MDT	Areal Flood Advisory	FGZ	Apache	117 min
Aug 6, 2:48 PM MDT	Special Weather Statement	FGZ		27 min
Aug 6, 3:25 PM MDT	Special Weather Statement	FGZ		50 min
Aug 6, 3:32 PM MDT	Special Weather Statement	FGZ	Apache	43 min
Aug 6, 3:39 PM MDT	Special Weather Statement	FGZ		36 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.