Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 39, NWS Flagstaff, AZ

July 14, 2021Coconino County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Jul 14, 2021, 4:02 PM MST for Coconino County, Arizona. It was in force for 31 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 14, 2021, 4:02 PM MST (23:02 UTC)
Expired
Jul 14, 2021, 4:33 PM MST
In force
31 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 Cedar City radar (KICX), 127 km from the middle of the area, began a volume at 23:03 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, 11.0 hours before the alert went out and 184 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 2021-07-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 17 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 2021-07-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 14 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
17 J/kg
Mixed-layer CIN
-187 J/kg
Mixed-layer LCL
1682 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
14 m²/s²
0-3 km storm-relative helicity
37 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

711 
WUUS55 KFGZ 142302
SVRFGZ
AZC005-142345-
/O.NEW.KFGZ.SV.W.0039.210714T2302Z-210714T2345Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
402 PM MST Wed Jul 14 2021

The National Weather Service in Flagstaff has issued a

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

* Until 445 PM MST/545 PM MDT/.

* At 402 PM MST/502 PM MDT/, a severe thunderstorm was located 8
  miles northwest of Marble Canyon, or 15 miles west of Page, moving
  southeast 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...
  Lees Ferry and Marble Canyon. 

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 3692 11183 3698 11175 3686 11154 3674 11170
TIME...MOT...LOC 2302Z 319DEG 10KT 3691 11174 

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

MCT
2 follow-up statements
478 
WWUS55 KFGZ 142311
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
411 PM MST Wed Jul 14 2021

AZC005-142345-
/O.CON.KFGZ.SV.W.0039.000000T0000Z-210714T2345Z/
Coconino-
411 PM MST Wed Jul 14 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM
MST/545 PM MDT/ FOR COCONINO COUNTY...

At 411 PM MST/511 PM MDT/, a severe thunderstorm was located near
Marble Canyon, or 14 miles west of Page, moving southeast at 10 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Lees Ferry and Marble Canyon. 

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 3688 11180 3695 11170 3686 11154 3674 11170
TIME...MOT...LOC 2311Z 319DEG 10KT 3689 11172 

HAIL...0.75IN
WIND...60MPH
 
$$

MCT
022 
WWUS55 KFGZ 142333
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
433 PM MST Wed Jul 14 2021

AZC005-142343-
/O.CAN.KFGZ.SV.W.0039.000000T0000Z-210714T2345Z/
Coconino-
433 PM MST Wed Jul 14 2021

...THE SEVERE THUNDERSTORM WARNING FOR COCONINO COUNTY IS
CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.  However heavy rain is
still possible with this thunderstorm.

LAT...LON 3688 11180 3695 11170 3686 11154 3674 11170
TIME...MOT...LOC 2330Z 319DEG 10KT 3684 11167 

$$

MCT

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 13, 5:20 PM MSTFlash Flood Warning Considerable damage threatFGZGila, Yavapai3 hr
Jul 13, 7:23 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Jul 14, 2:39 AM MSTSpecial Weather StatementFGZYavapai36 min
Jul 14, 3:06 AM MSTAreal Flood AdvisoryFGZYavapai111 min
Jul 14, 3:24 AM MSTSpecial Weather StatementFGZYavapai36 min
Jul 14, 3:38 AM MSTAreal Flood AdvisoryFGZYavapai2 hr
Jul 14, 3:59 AM MSTSpecial Weather StatementFGZYavapai46 min
Jul 14, 4:24 AM MSTAreal Flood AdvisoryFGZYavapai74 min
Jul 14, 4:30 AM MSTSpecial Weather StatementFGZ45 min
Jul 14, 4:45 AM MSTSpecial Weather StatementFGZ45 min
Jul 14, 5:23 AM MSTSpecial Weather StatementFGZ37 min
Jul 14, 9:53 AM MSTFlash Flood WatchFGZApache, Coconino, Navajo17 hr
Jul 14, 1:47 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino5 hr
Jul 14, 2:13 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Jul 14, 2:39 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Jul 14, 2:57 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai3 hr
Jul 14, 3:36 PM MSTFlash Flood Warning Considerable damage threatFGZCoconino3 hr
Jul 14, 4:24 PM MSTFlash Flood Warning Considerable damage threatFGZYavapai111 min
Jul 14, 4:54 PM MSTFlash Flood Warning Considerable damage threatFGZNavajo111 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.