Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 57, NWS Flagstaff, AZ

July 18, 2021Gila County, Yavapai County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 18, 2021, 4:59 PM MST for Gila County, Yavapai County, Arizona. It was in force for 46 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 18, 2021, 4:59 PM MST (23:59 UTC)
Expired: Jul 18, 2021, 5:45 PM MST
In force: 46 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

Counties Gila County, AZ, Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 69 km from the middle of the area, began a volume at 00:00 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

Phoenix, AZ (KPSR), launched 12:00Z, 12.0 hours before the alert went out and 81 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: 453 J/kg
Mixed-layer CIN: -202 J/kg
Mixed-layer LCL: 2153 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 7 m²/s²
0-3 km storm-relative helicity: 40 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

The text

As transmitted.

399 
WUUS55 KFGZ 182359
SVRFGZ
AZC007-025-190045-
/O.NEW.KFGZ.SV.W.0057.210718T2359Z-210719T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
459 PM MST Sun Jul 18 2021

The National Weather Service in Flagstaff has issued a

* Severe Thunderstorm Warning for...
  Gila County in east central Arizona...
  Yavapai County in west central Arizona...

* Until 545 PM MST.

* At 459 PM MST, a severe thunderstorm was located near Punkin
  Center, or 10 miles east of Sycamore Creek, moving west at 20 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...
  Jakes Corner and Deer Creek. 

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 3390 11126 3397 11141 3401 11143 3400 11150
      3400 11167 3407 11167 3410 11141 3400 11119
      3385 11121
TIME...MOT...LOC 2359Z 093DEG 19KT 3392 11130 

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

EL

2 follow-up statements

561 
WWUS55 KFGZ 190013
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
513 PM MST Sun Jul 18 2021

AZC007-025-190045-
/O.CON.KFGZ.SV.W.0057.000000T0000Z-210719T0045Z/
Gila-Yavapai-
513 PM MST Sun Jul 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 545 PM MST
FOR GILA AND YAVAPAI COUNTIES...

At 512 PM MST, a severe thunderstorm was located near Sycamore Creek,
moving west at 20 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...
Jakes Corner and Deer Creek. 

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 3390 11126 3397 11141 3401 11143 3400 11150
      3400 11167 3407 11167 3410 11141 3400 11119
      3385 11121
TIME...MOT...LOC 0012Z 093DEG 19KT 3392 11139 

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

EL

485 
WWUS55 KFGZ 190050
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
550 PM MST Sun Jul 18 2021

AZC007-025-190059-
/O.EXP.KFGZ.SV.W.0057.000000T0000Z-210719T0045Z/
Gila-Yavapai-
550 PM MST Sun Jul 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR GILA AND YAVAPAI COUNTIES HAS
EXPIRED...
        
The storm which prompted the warning has moved out of the warned 
area. Therefore, the warning has been allowed to expire.

LAT...LON 3390 11126 3397 11141 3401 11143 3400 11150
      3400 11167 3407 11167 3410 11141 3400 11119
      3385 11121
TIME...MOT...LOC 0049Z 093DEG 19KT 3393 11157 

$$

EL

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 10:58 AM MST	Severe Thunderstorm Warning	FGZ	Yavapai	32 min
Jul 18, 11:14 AM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	3 hr
Jul 18, 12:16 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	29 min
Jul 18, 1:03 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	3 hr
Jul 18, 1:08 PM MST	Special Weather Statement	FGZ		37 min
Jul 18, 1:34 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	3 hr
Jul 18, 2:12 PM MST	Severe Thunderstorm Warning	FGZ	Gila, Navajo	33 min
Jul 18, 2:18 PM MST	Severe Thunderstorm Warning	FGZ	Gila	42 min
Jul 18, 2:31 PM MST	Areal Flood Advisory	FGZ	Coconino	100 min
Jul 18, 2:33 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	42 min
Jul 18, 2:53 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Gila, Navajo	102 min
Jul 18, 3:02 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino	108 min
Jul 18, 3:47 PM MST	Severe Thunderstorm Warning	FGZ	Gila	43 min
Jul 18, 3:54 PM MST	Special Weather Statement	FGZ		51 min
Jul 18, 4:10 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Yavapai	51 min
Jul 18, 4:32 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Navajo	4 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.