Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 56, NWS Flagstaff, AZ

July 18, 2021Gila County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 18, 2021, 3:47 PM MST for Gila County, Arizona. It was in force for 43 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, 3:47 PM MST (22:47 UTC)
Expired: Jul 18, 2021, 4:30 PM MST
In force: 43 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

County Gila County, AZ

The radar

The Flagstaff radar (KFSX), 72 km from the middle of the area, began a volume at 22:47 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, 10.8 hours before the alert went out and 95 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.

674 
WUUS55 KFGZ 182247
SVRFGZ
AZC007-182330-
/O.NEW.KFGZ.SV.W.0056.210718T2247Z-210718T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
347 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...

* Until 430 PM MST.

* At 346 PM MST, a severe thunderstorm was located 13 miles northeast
  of Tonto Basin, or 18 miles north of Roosevelt, and is nearly
  stationary.

  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.

* This severe thunderstorm will remain over mainly rural areas of
  Gila County.

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.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 3387 11123 3407 11122 3403 11102 3394 11099
      3388 11102 3385 11121
TIME...MOT...LOC 2246Z 093DEG 3KT 3394 11110 

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

EL

2 follow-up statements

457 
WWUS55 KFGZ 182259
SVSFGZ

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

AZC007-182330-
/O.CON.KFGZ.SV.W.0056.000000T0000Z-210718T2330Z/
Gila-
359 PM MST Sun Jul 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM MST
FOR GILA COUNTY...

At 358 PM MST, a severe thunderstorm was located 12 miles northeast
of Tonto Basin, or 18 miles north of Roosevelt, and is nearly
stationary.

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 Gila
County.

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.

&&

LAT...LON 3395 11120 3406 11120 3402 11102 3394 11099
      3388 11102 3391 11114
TIME...MOT...LOC 2258Z 093DEG 3KT 3394 11111 

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

EL

661 
WWUS55 KFGZ 182321
SVSFGZ

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

AZC007-182331-
/O.EXP.KFGZ.SV.W.0056.000000T0000Z-210718T2330Z/
Gila-
421 PM MST Sun Jul 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR GILA COUNTY WILL EXPIRE AT 430
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. However heavy rain 
is still possible with this thunderstorm.

LAT...LON 3395 11120 3406 11120 3402 11102 3394 11099
      3388 11102 3391 11114
TIME...MOT...LOC 2321Z 093DEG 3KT 3394 11113 

$$

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, 3:54 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
Jul 18, 4:59 PM MST	Severe Thunderstorm Warning	FGZ	Gila, Yavapai	46 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.