Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 41, NWS Flagstaff, AZ

July 16, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 16, 2021, 1:16 PM MST for Coconino County, Arizona. It was in force for 29 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 16, 2021, 1:16 PM MST (20:16 UTC)
Expired
Jul 16, 2021, 1:45 PM MST
In force
29 min
Issued by
NWS Flagstaff, AZ
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Coconino County, AZ

The radar

The Flagstaff radar (KFSX), 71 km from the middle of the area, began a volume at 20:20 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, 8.3 hours before the alert went out and 23 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 2021-07-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 487 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 2021-07-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 77 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
487 J/kg
Mixed-layer CIN
-59 J/kg
Mixed-layer LCL
1090 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
77 m²/s²
0-3 km storm-relative helicity
88 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

224 
WUUS55 KFGZ 162016
SVRFGZ
AZC005-162045-
/O.NEW.KFGZ.SV.W.0041.210716T2016Z-210716T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
116 PM MST Fri Jul 16 2021

The National Weather Service in Flagstaff has issued a

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

* Until 145 PM MST.

* At 115 PM MST, a severe thunderstorm was located near Flagstaff,
  moving south 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...
  Flagstaff, Walnut Canyon National Monument, Upper Lake Mary Boat
  Ramps, Walnut Canyon Visitors Center, Lower Lake Mary, Canyon Vista
  Campground, Lake View Campground and Upper Lake Mary.

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 3522 11163 3521 11148 3504 11150 3505 11153
      3508 11165
TIME...MOT...LOC 2015Z 019DEG 7KT 3516 11158 

HAIL...1.00IN
WIND...60MPH
 
$$
ET
1 follow-up statement
409 
WWUS55 KFGZ 162041
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
141 PM MST Fri Jul 16 2021

AZC005-162049-
/O.EXP.KFGZ.SV.W.0041.000000T0000Z-210716T2045Z/
Coconino-
141 PM MST Fri Jul 16 2021

...THE SEVERE THUNDERSTORM WARNING FOR COCONINO COUNTY WILL EXPIRE AT
145 PM MST...
                
The storm which prompted the warning has weakened below severe 
limits. Therefore, the warning will be allowed to expire and will be 
replaced with a Significant Weather Advisory However small hail, 
gusty winds and heavy rain are still possible with this thunderstorm.

LAT...LON 3522 11163 3521 11148 3504 11150 3505 11153
      3508 11165
TIME...MOT...LOC 2039Z 019DEG 7KT 3513 11159 

$$

ET

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 15, 5:20 PM MSTAreal Flood AdvisoryFGZYavapai115 min
Jul 15, 6:33 PM MSTSevere Thunderstorm WarningFGZYavapai27 min
Jul 15, 6:55 PM MSTAreal Flood AdvisoryFGZYavapai3 hr
Jul 15, 8:21 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai114 min
Jul 16, 11:56 AM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Jul 16, 12:03 PM MSTAreal Flood AdvisoryFGZYavapai2 hr
Jul 16, 12:36 PM MSTAreal Flood AdvisoryFGZCoconino2 hr
Jul 16, 12:52 PM MSTSpecial Weather StatementFGZ23 min
Jul 16, 1:20 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino115 min
Jul 16, 1:24 PM MSTSevere Thunderstorm WarningFGZGila, Navajo51 min
Jul 16, 1:44 PM MSTSpecial Weather StatementFGZ46 min
Jul 16, 2:13 PM MSTSevere Thunderstorm WarningFGZGila, Navajo32 min
Jul 16, 2:25 PM MSTAreal Flood AdvisoryFGZCoconino3 hr
Jul 16, 2:59 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino61 min
Jul 16, 3:14 PM MSTSpecial Weather StatementFGZ31 min
Jul 16, 3:43 PM MSTSevere Thunderstorm WarningFGZCoconino, Yavapai32 min
Jul 16, 4:18 PM MSTSevere Thunderstorm WarningFGZYavapai12 min
Jul 16, 4:34 PM MSTSevere Thunderstorm WarningFGZGila41 min
Jul 16, 4:41 PM MSTFlash Flood Warning Considerable damage threatFGZGila3 hr
Jul 16, 4:48 PM MSTSevere Thunderstorm WarningFGZCoconino, Gila20 min
Jul 16, 4:59 PM MSTSevere Thunderstorm WarningFGZGila, Yavapai15 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.