Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 71, NWS Flagstaff, AZ

July 24, 2021Navajo County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 24, 2021, 5:20 PM MDT for Navajo County, Arizona. It was in force for 25 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, 5:20 PM MDT (23:20 UTC)
Expired
Jul 24, 2021, 5:45 PM MDT
In force
25 min
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Navajo County, AZ

The radar

The Flagstaff radar (KFSX), 167 km from the middle of the area, began a volume at 23:24 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 12:00Z, 11.3 hours before the alert went out and 156 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 2021-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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 2021-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1053 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
-9 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

257 
WUUS55 KFGZ 242320
SVRFGZ
AZC017-242345-
/O.NEW.KFGZ.SV.W.0071.210724T2320Z-210724T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
420 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...

* Until 445 PM MST.

* At 419 PM MST, a severe thunderstorm was located near Keams Canyon,
  moving west at 10 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...
  Keams Canyon, First Mesa and Polacca. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3596 11018 3577 11016 3570 11037 3594 11044
TIME...MOT...LOC 2319Z 078DEG 7KT 3587 11023 

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

TPS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 23, 6:56 PM MDTSevere Thunderstorm WarningFGZApache34 min
Jul 23, 7:00 PM MDTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Jul 24, 12:13 AM MDTAreal Flood AdvisoryFGZApache, Coconino, Gila, Navajo5 hr
Jul 24, 8:22 AM MDTAreal Flood AdvisoryFGZApache, Coconino, Navajo16 hr
Jul 24, 2:28 PM MDTSevere Thunderstorm WarningFGZApache32 min
Jul 24, 2:56 PM MDTSevere Thunderstorm WarningFGZApache34 min
Jul 24, 3:16 PM MDTSevere Thunderstorm WarningFGZApache29 min
Jul 24, 3:43 PM MDTSevere Thunderstorm WarningFGZApache32 min
Jul 24, 5:01 PM MDTFlash Flood Warning Considerable damage threatFGZYavapai119 min
Jul 24, 5:05 PM MDTFlash Flood Warning Considerable damage threatFGZApache3 hr
Jul 24, 5:18 PM MDTFlash Flood Warning Considerable damage threatFGZApache, Navajo3 hr
Jul 24, 5:51 PM MDTSevere Thunderstorm WarningFGZNavajo39 min
Jul 24, 5:58 PM MDTSevere Thunderstorm WarningFGZNavajo32 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.