Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 178, NWS Flagstaff, AZ

September 27, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Sep 27, 2021, 6:10 PM MST for Coconino County, Arizona. It was in force for 18 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
Sep 27, 2021, 6:10 PM MST (01:10 UTC)
Expired
Sep 27, 2021, 6:28 PM MST
In force
18 min
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

County Coconino County, AZ

The radar

The Cedar City radar (KICX), 116 km from the middle of the area, began a volume at 01:12 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, 1.2 hours before the alert went out and 163 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 2021-09-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 177 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 2021-09-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 80 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
177 J/kg
Mixed-layer CIN
-40 J/kg
Mixed-layer LCL
849 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
80 m²/s²
0-3 km storm-relative helicity
125 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

665 
WUUS55 KFGZ 280110
SVRFGZ
AZC005-280145-
/O.NEW.KFGZ.SV.W.0178.210928T0110Z-210928T0145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
610 PM MST Mon Sep 27 2021

The National Weather Service in Flagstaff has issued a

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

* Until 645 PM MST.

* At 610 PM MST, a severe thunderstorm was located 12 miles southwest
  of Jacob Lake, moving southwest at 15 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3668 11241 3663 11229 3649 11234 3659 11255
TIME...MOT...LOC 0110Z 030DEG 16KT 3661 11240 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

McCollum
1 follow-up statement
886 
WWUS55 KFGZ 280128
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
628 PM MST Mon Sep 27 2021

AZC005-280136-
/O.CAN.KFGZ.SV.W.0178.000000T0000Z-210928T0145Z/
Coconino-
628 PM MST Mon Sep 27 2021

...THE SEVERE THUNDERSTORM WARNING FOR COCONINO COUNTY IS
CANCELLED...
                
The storm 12 miles southwest of Jacobs Lake 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.

LAT...LON 3668 11241 3663 11229 3649 11234 3659 11255
TIME...MOT...LOC 0121Z 030DEG 16KT 3655 11245 

$$

McCollum

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 27, 5:29 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Sep 27, 5:41 PM MSTSevere Thunderstorm WarningFGZCoconino34 min
Sep 27, 6:14 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino2 hr
Sep 28, 2:35 PM MSTSpecial Weather StatementFGZ25 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.