Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 74, NWS Flagstaff, AZ

July 24, 2021Coconino County, Navajo County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 24, 2021, 5:30 PM MST for Coconino County, Navajo County, Arizona. It was in force for 30 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, 5:30 PM MST (00:30 UTC)
Expired: Jul 24, 2021, 6:00 PM MST
In force: 30 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Hail: 1.25 in
Wind: 50.0 mph

Counties Coconino County, AZ, Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 211 km from the middle of the area, began a volume at 00:29 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, 0.5 hours before the alert went out and 164 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: 968 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 899 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 2 m²/s²
0-3 km storm-relative helicity: 68 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

As transmitted.

837 
WUUS55 KFGZ 250030
SVRFGZ
AZC005-017-250100-
/O.NEW.KFGZ.SV.W.0074.210725T0030Z-210725T0100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
530 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...
  Coconino County in north central Arizona...

* Until 600 PM MST/700 PM MDT/.

* At 529 PM MST/629 PM MDT/, a severe thunderstorm was located near 
  Cow Springs and Navajo Trail, moving northwest at 15 mph.

  HAZARD...Half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Cow Springs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3643 11061 3630 11068 3640 11097 3661 11084
TIME...MOT...LOC 0029Z 128DEG 13KT 3640 11073 

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

McCollum

2 follow-up statements

120 
WWUS55 KFGZ 250045
SVSFGZ

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

AZC005-017-250100-
/O.CON.KFGZ.SV.W.0074.000000T0000Z-210725T0100Z/
Navajo-Coconino-
545 PM MST Sat Jul 24 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 600 PM
MST/700 PM MDT/ FOR NAVAJO AND COCONINO COUNTIES...

At 543 PM MST/643 PM MDT/, a severe thunderstorm was located over 
Cow Springs and Navajo Trail, moving northwest at 15 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Cow Springs and travelers along Navajo Trail.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3643 11061 3630 11068 3640 11097 3661 11084
TIME...MOT...LOC 0043Z 128DEG 13KT 3643 11078 

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

McCollum

872 
WWUS55 KFGZ 250051
SVSFGZ

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

AZC005-017-250101-
/O.EXP.KFGZ.SV.W.0074.000000T0000Z-210725T0100Z/
Navajo-Coconino-
551 PM MST Sat Jul 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR NAVAJO AND COCONINO COUNTIES
WILL EXPIRE AT 600 PM MST/700 PM MDT/...
                
The storm near Cow Springs 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 3643 11061 3630 11068 3640 11097 3661 11084
TIME...MOT...LOC 0051Z 128DEG 13KT 3643 11079 

$$

McCollum

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 24, 7:12 PM MST	Areal Flood Advisory	FGZ	Coconino, Navajo	3 hr
Jul 24, 7:50 PM MST	Areal Flood Advisory	FGZ	Coconino	3 hr
Jul 24, 8:49 PM MST	Areal Flood Advisory	FGZ	Coconino, Yavapai	3 hr
Jul 24, 9:32 PM MST	Areal Flood Advisory	FGZ	Yavapai	3 hr
Jul 24, 10:47 PM MST	Areal Flood Warning	FGZ	Navajo	6 hr
Jul 24, 11:06 PM MST	Areal Flood Advisory	FGZ	Apache, Coconino, Navajo	12 hr
Jul 25, 2:30 AM MST	Areal Flood Advisory	FGZ	Coconino, Navajo	24 hr
Jul 25, 2:51 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	6 hr
Jul 25, 4:58 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 25, 9:15 AM MST	Areal Flood Warning	FGZ	Apache, Coconino, Navajo	13 hr
Jul 25, 11:05 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	11 hr
Jul 25, 12:39 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Gila, Yavapai	3 hr
Jul 25, 1:51 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 25, 2:27 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Yavapai	108 min
Jul 25, 2:52 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 25, 3:28 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	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.