Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 89, NWS Flagstaff, AZ

August 2, 2021Apache County, Navajo County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 2, 2021, 2:44 PM MST for Apache County, Navajo County, Arizona. It was in force for 31 min. 1 report 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: Aug 2, 2021, 2:44 PM MST (21:44 UTC)
Expired: Aug 2, 2021, 3:15 PM MST
In force: 31 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

Counties Apache County, AZ, Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 150 km from the middle of the area, began a volume at 21:46 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
Aug 2, 3:00 PM MST	HAIL 0.88	East Fork, AZ	PUBLIC REPORTS NICKEL SIZED HAIL.

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

The nearest sounding before it

Phoenix, AZ (KPSR), launched 12:00Z, 9.7 hours before the alert went out and 195 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: 258 J/kg
Mixed-layer CIN: -235 J/kg
Mixed-layer LCL: 2514 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: 46 m²/s²
0-3 km storm-relative helicity: 60 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

951 
WUUS55 KFGZ 022144
SVRFGZ
AZC001-017-022215-
/O.NEW.KFGZ.SV.W.0089.210802T2144Z-210802T2215Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
244 PM MST Mon Aug 2 2021

The National Weather Service in Flagstaff has issued a

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

* Until 315 PM MST.

* At 244 PM MST, a severe thunderstorm was located near Turkey Creek,
  or 33 miles south of Show Low, moving southeast at 15 mph.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Turkey Creek, Seven Mile, Fort Apache, Whiteriver and East Fork. 

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 3380 10999 3384 10985 3370 10976 3365 10994
TIME...MOT...LOC 2144Z 332DEG 15KT 3378 10985 

HAIL...1.25IN
WIND...60MPH
 
$$

ET

2 follow-up statements

154 
WWUS55 KFGZ 022156
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
256 PM MST Mon Aug 2 2021

AZC001-017-022215-
/O.CON.KFGZ.SV.W.0089.000000T0000Z-210802T2215Z/
Apache-Navajo-
256 PM MST Mon Aug 2 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 315 PM MST
FOR APACHE AND NAVAJO COUNTIES...

At 255 PM MST, a severe thunderstorm was located 8 miles southeast of
Turkey Creek, or 36 miles south of Show Low, moving southeast at 15
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.

This severe thunderstorm will remain over mainly rural areas of
Apache and Navajo Counties.

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 3378 10998 3382 10984 3370 10976 3365 10994
TIME...MOT...LOC 2155Z 332DEG 15KT 3374 10982 

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

ET

882 
WWUS55 KFGZ 022205
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
305 PM MST Mon Aug 2 2021

AZC001-017-022215-
/O.EXP.KFGZ.SV.W.0089.000000T0000Z-210802T2215Z/
Apache-Navajo-
305 PM MST Mon Aug 2 2021

...THE SEVERE THUNDERSTORM WARNING FOR APACHE AND NAVAJO COUNTIES
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.  

LAT...LON 3378 10998 3382 10984 3370 10976 3365 10994
TIME...MOT...LOC 2205Z 332DEG 15KT 3371 10980 

$$

ET

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 1, 5:05 PM MST	Areal Flood Advisory	FGZ	Coconino	3 hr
Aug 1, 5:11 PM MST	Severe Thunderstorm Warning	FGZ	Gila, Navajo	49 min
Aug 1, 5:22 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Aug 1, 5:28 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila, Navajo	5 hr
Aug 1, 5:49 PM MST	Areal Flood Advisory	FGZ	Coconino	3 hr
Aug 1, 5:49 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache, Navajo	3 hr
Aug 1, 6:04 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Aug 1, 6:20 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila, Navajo	3 hr
Aug 1, 7:55 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila	2 hr
Aug 1, 8:26 PM MST	Flash Flood Warning	FGZ	Gila	115 min
Aug 1, 8:59 PM MST	Flash Flood Warning	FGZ	Gila	85 min
Aug 1, 9:47 PM MST	Special Weather Statement	FGZ		28 min
Aug 2, 1:59 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Apache	3 hr
Aug 2, 2:23 PM MST	Severe Thunderstorm Warning	FGZ	Apache, Navajo	22 min
Aug 2, 4:06 PM MST	Special Weather Statement	FGZ	Apache	39 min
Aug 2, 4:14 PM MST	Special Weather Statement	FGZ		31 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.