Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 2, NWS Flagstaff, AZ

June 17, 2021Navajo County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jun 17, 2021, 7:25 PM MDT for Navajo County, Arizona. It was in force for 35 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
Jun 17, 2021, 7:25 PM MDT (01:25 UTC)
Expired
Jun 17, 2021, 8:00 PM MDT
In force
35 min
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Tornado
Possible
Hail
0.75 in
Wind
70.0 mph

County Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 111 km from the middle of the area, began a volume at 01:24 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, 1.4 hours before the alert went out and 172 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 00:00Z on 2021-06-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 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 00:00Z on 2021-06-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
7 J/kg
Mixed-layer CIN
-128 J/kg
Mixed-layer LCL
3573 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
44 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

712 
WUUS55 KFGZ 180125
SVRFGZ
AZC017-180200-
/O.NEW.KFGZ.SV.W.0002.210618T0125Z-210618T0200Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
625 PM MST Thu Jun 17 2021

The National Weather Service in Flagstaff has issued a

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

* Until 700 PM MST.

* At 624 PM MST, a severe thunderstorm was located near Woodruff, or
  33 miles north of Show Low, moving west at 15 mph.

  HAZARD...70 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect considerable tree damage. Damage is likely to 
           mobile homes, roofs, and outbuildings.

* Locations impacted include...
  Woodruff.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Intense thunderstorm lines can produce brief tornadoes and widespread
significant wind damage. Although a tornado is not immediately
likely, it is best to move to an interior room on the lowest floor of
a building. This storm may cause serious injury and significant
property damage.

&&

LAT...LON 3482 10990 3463 10993 3465 11015 3482 11014
TIME...MOT...LOC 0124Z 108DEG 11KT 3473 11000 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...70MPH
 
$$
1 follow-up statement
763 
WWUS55 KFGZ 180158
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
658 PM MST Thu Jun 17 2021

AZC017-180206-
/O.EXP.KFGZ.SV.W.0002.000000T0000Z-210618T0200Z/
Navajo-
658 PM MST Thu Jun 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR NAVAJO COUNTY WILL EXPIRE AT
700 PM MST...
                
The storm near Woodruff, which prompted the severe thunderstorm 
warning, has weakened to below severe limits. The storm no longer 
poses an immediate threat to life or property.

Therefore, the warning will be allowed to expire. However, gusty 
winds to 45 mph are still possible with this storm, all along SR 77 
from Holbrook to Snowflake, until 730 PM MST.

LAT...LON 3482 10990 3463 10993 3465 11015 3482 11014
TIME...MOT...LOC 0156Z 108DEG 11KT 3476 11011 

$$

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.