Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 72, NWS Flagstaff, AZ

July 24, 2021Navajo County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 24, 2021, 5:51 PM MDT for Navajo County, Arizona. It was in force for 39 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: Jul 24, 2021, 5:51 PM MDT (23:51 UTC)
Expired: Jul 24, 2021, 6:30 PM MDT
In force: 39 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Hail: 1.25 in
Wind: 50.0 mph

County Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 162 km from the middle of the area, began a volume at 23:53 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, 11.9 hours before the alert went out and 146 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1053 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: -9 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

516 
WUUS55 KFGZ 242351
SVRFGZ
AZC017-250030-
/O.NEW.KFGZ.SV.W.0072.210724T2351Z-210725T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
451 PM MST Sat Jul 24 2021

The National Weather Service in Flagstaff has issued a

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

* Until 530 PM MST.

* At 450 PM MST, a severe thunderstorm was located over First Mesa,
  or 8 miles west of Keams Canyon, moving west at 10 mph.

  HAZARD...Half dollar size hail. Wind gusts to 50 mph.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  First Mesa, Second Mesa, Shongopovi, Polacca and Hopi Reservation. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3594 11030 3578 11029 3575 11054 3595 11054
TIME...MOT...LOC 2350Z 087DEG 9KT 3585 11034 

HAIL...1.25IN
WIND...<50MPH
 
$$

McCollum

1 follow-up statement

811 
WWUS55 KFGZ 250023
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
523 PM MST Sat Jul 24 2021

AZC017-250032-
/O.EXP.KFGZ.SV.W.0072.000000T0000Z-210725T0030Z/
Navajo-
523 PM MST Sat Jul 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR NAVAJO COUNTY WILL EXPIRE AT
530 PM MST...
                
The storm between Polacca and Second Mesa 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 3594 11030 3578 11029 3575 11054 3595 11054
TIME...MOT...LOC 0022Z 087DEG 9KT 3585 11043 

$$

McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 23, 6:56 PM MDT	Severe Thunderstorm Warning	FGZ	Apache	34 min
Jul 23, 7:00 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 24, 12:13 AM MDT	Areal Flood Advisory	FGZ	Apache, Coconino, Gila, Navajo	5 hr
Jul 24, 8:22 AM MDT	Areal Flood Advisory	FGZ	Apache, Coconino, Navajo	16 hr
Jul 24, 2:28 PM MDT	Severe Thunderstorm Warning	FGZ	Apache	32 min
Jul 24, 2:56 PM MDT	Severe Thunderstorm Warning	FGZ	Apache	34 min
Jul 24, 3:16 PM MDT	Severe Thunderstorm Warning	FGZ	Apache	29 min
Jul 24, 3:43 PM MDT	Severe Thunderstorm Warning	FGZ	Apache	32 min
Jul 24, 5:01 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	119 min
Jul 24, 5:05 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Apache	3 hr
Jul 24, 5:18 PM MDT	Flash Flood Warning Considerable damage threat	FGZ	Apache, Navajo	3 hr
Jul 24, 5:20 PM MDT	Severe Thunderstorm Warning	FGZ	Navajo	25 min
Jul 24, 5:58 PM MDT	Severe Thunderstorm Warning	FGZ	Navajo	32 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.