Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 63, NWS Flagstaff, AZ

July 21, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 21, 2021, 3:21 PM MST for Coconino County, Arizona. It was in force for 26 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 21, 2021, 3:21 PM MST (22:21 UTC)
Expired
Jul 21, 2021, 3:47 PM MST
In force
26 min
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Coconino County, AZ

The radar

The Cedar City radar (KICX), 176 km from the middle of the area, began a volume at 22:21 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, 10.4 hours before the alert went out and 103 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-pSkew-T log-p diagram, Flgstf/Belemont, AZ at 12:00Z on 2021-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 77 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2021-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
77 J/kg
Mixed-layer CIN
-129 J/kg
Mixed-layer LCL
1785 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
-11 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

709 
WUUS55 KFGZ 212221
SVRFGZ
AZC005-212300-
/O.NEW.KFGZ.SV.W.0063.210721T2221Z-210721T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
321 PM MST Wed Jul 21 2021

The National Weather Service in Flagstaff has issued a

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

* Until 400 PM MST.

* At 320 PM MST, a severe thunderstorm was located over Pima Point At
  Grand Canyon, or 20 miles west of Desert View at Grand Canyon,
  moving north 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.

* Locations impacted include...
  Maricopa Point At Grand Canyon, Yaqui Point At Grand Canyon,
  Hermit's Rest At Grand Canyon, Shoshone Point At Grand Canyon, Pima
  Point At Grand Canyon, Bright Angel Point, South Rim Visitors
  Center, Hopi Point At Grand Canyon, North Rim Entrance Station and
  Grand Canyon Village.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and continuous cloud to ground 
lightning is occurring with this storm. Move indoors immediately, 
especially if hiking in the Grand Canyon. Lightning is one of 
nature's leading killers. Remember, if you can hear thunder, you are 
close enough to be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3602 11204 3598 11214 3599 11225 3631 11236
      3635 11203
TIME...MOT...LOC 2220Z 171DEG 13KT 3608 11219 

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

EL
2 follow-up statements
825 
WWUS55 KFGZ 212237
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
337 PM MST Wed Jul 21 2021

AZC005-212300-
/O.CON.KFGZ.SV.W.0063.000000T0000Z-210721T2300Z/
Coconino-
337 PM MST Wed Jul 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM MST
FOR COCONINO COUNTY...

At 335 PM MST, a severe thunderstorm was located near Pima Point At
Grand Canyon, or 21 miles west of Desert View at Grand Canyon, moving
north at 15 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Maricopa Point At Grand Canyon, Yaqui Point At Grand Canyon, Hermit's
Rest At Grand Canyon, Shoshone Point At Grand Canyon, Pima Point At
Grand Canyon, Bright Angel Point, South Rim Visitors Center, Hopi
Point At Grand Canyon, North Rim Entrance Station and Grand Canyon
Village.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3602 11204 3598 11214 3599 11225 3631 11236
      3635 11203
TIME...MOT...LOC 2235Z 171DEG 13KT 3614 11220 

HAIL...0.75IN
WIND...60MPH
 
$$

EL
110 
WWUS55 KFGZ 212247
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
347 PM MST Wed Jul 21 2021

AZC005-212256-
/O.CAN.KFGZ.SV.W.0063.000000T0000Z-210721T2300Z/
Coconino-
347 PM MST Wed Jul 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR COCONINO COUNTY IS
CANCELLED...
                
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 has been cancelled. However gusty winds, 
lightning, and heavy rain are still possible with this thunderstorm.

LAT...LON 3602 11204 3598 11214 3599 11225 3631 11236
      3635 11203
TIME...MOT...LOC 2241Z 171DEG 13KT 3618 11221 

$$

EL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 6:16 PM MSTSpecial Weather StatementFGZ29 min
Jul 20, 7:32 PM MSTSevere Thunderstorm WarningFGZNavajo28 min
Jul 20, 7:55 PM MSTFlash Flood Warning Considerable damage threatFGZNavajo2 hr
Jul 20, 8:33 PM MSTFlash Flood Warning Considerable damage threatFGZNavajo117 min
Jul 21, 12:17 AM MSTFlash Flood Warning Considerable damage threatFGZGila118 min
Jul 21, 2:38 AM MSTFlash Flood WatchFGZApache, Coconino, Gila, Navajo, Yavapai5 days
Jul 21, 10:19 AM MSTSpecial Weather StatementFGZYavapai26 min
Jul 21, 10:48 AM MSTFlash Flood Warning Considerable damage threatFGZYavapai2 hr
Jul 21, 12:03 PM MSTSpecial Weather StatementFGZYavapai42 min
Jul 21, 12:13 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai56 min
Jul 21, 12:20 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai114 min
Jul 21, 12:35 PM MSTSpecial Weather StatementFGZ40 min
Jul 21, 12:47 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino118 min
Jul 21, 12:54 PM MSTSpecial Weather StatementFGZ36 min
Jul 21, 1:06 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino92 min
Jul 21, 1:24 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino110 min
Jul 21, 1:27 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai74 min
Jul 21, 1:57 PM MSTSpecial Weather StatementFGZYavapai48 min
Jul 21, 2:01 PM MSTAreal Flood AdvisoryFGZYavapai119 min
Jul 21, 2:05 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino2 hr
Jul 21, 2:22 PM MSTAreal Flood AdvisoryFGZCoconino3 hr
Jul 21, 2:30 PM MSTSpecial Weather StatementFGZ45 min
Jul 21, 2:36 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai54 min
Jul 21, 2:53 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino82 min
Jul 21, 2:57 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai60 min
Jul 21, 2:59 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai60 min
Jul 21, 3:34 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino98 min
Jul 21, 3:49 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Jul 21, 4:35 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino115 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2021Every 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.