Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 113, NWS Flagstaff, AZ

August 15, 2021Coconino County, Yavapai County, Arizona

NWS Flagstaff, AZ issued this severe thunderstorm warning at Aug 15, 2021, 1:43 PM MST for Coconino County, Yavapai County, Arizona. It was in force for 36 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: Aug 15, 2021, 1:43 PM MST (20:43 UTC)
Expired: Aug 15, 2021, 2:19 PM MST
In force: 36 min
Issued by: NWS Flagstaff, AZ
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Coconino County, AZ, Yavapai County, AZ

The radar

The Flagstaff radar (KFSX), 83 km from the middle of the area, began a volume at 20:45 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, 8.7 hours before the alert went out and 34 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 9 J/kg
Mixed-layer CIN: -172 J/kg
Mixed-layer LCL: 2026 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 41 m²/s²
0-3 km storm-relative helicity: 73 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

168 
WUUS55 KFGZ 152043
SVRFGZ
AZC005-025-152130-
/O.NEW.KFGZ.SV.W.0113.210815T2043Z-210815T2130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Flagstaff AZ
143 PM MST Sun Aug 15 2021

The National Weather Service in Flagstaff has issued a

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

* Until 230 PM MST.

* At 143 PM MST, a severe thunderstorm was located 12 miles northeast
  of Perkinsville, or 13 miles northwest of Sedona, moving southwest
  at 20 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Sedona and Red Rock State Park. 

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 3507 11202 3504 11179 3480 11182 3482 11225
TIME...MOT...LOC 2043Z 024DEG 17KT 3497 11199 

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

$$

RR

1 follow-up statement

354 
WWUS55 KFGZ 152119
SVSFGZ

Severe Weather Statement
National Weather Service Flagstaff AZ
219 PM MST Sun Aug 15 2021

AZC005-025-152128-
/O.CAN.KFGZ.SV.W.0113.000000T0000Z-210815T2130Z/
Yavapai-Coconino-
219 PM MST Sun Aug 15 2021

...THE SEVERE THUNDERSTORM WARNING FOR YAVAPAI AND COCONINO COUNTIES
IS CANCELLED...
                
The storm 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 3507 11202 3504 11179 3480 11182 3482 11225
TIME...MOT...LOC 2113Z 024DEG 17KT 3481 11207 

$$

RR

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 15, 12:37 PM MST	Special Weather Statement	FGZ		23 min
Aug 15, 12:52 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	38 min
Aug 15, 1:22 PM MST	Severe Thunderstorm Warning	FGZ	Apache	38 min
Aug 15, 2:17 PM MST	Severe Thunderstorm Warning	FGZ	Coconino	43 min
Aug 15, 2:33 PM MST	Flash Flood Warning Considerable damage threat	FGZ	Coconino, Yavapai	3 hr
Aug 15, 2:42 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	48 min
Aug 15, 3:36 PM MST	Severe Thunderstorm Warning	FGZ	Yavapai	39 min
Aug 15, 3:49 PM MST	Severe Thunderstorm Warning	FGZ	Coconino, Navajo	26 min
Aug 15, 3:52 PM MST	Severe Thunderstorm Warning	FGZ	Navajo	23 min
Aug 15, 4:49 PM MST	Severe Thunderstorm Warning	FGZ	Apache	41 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2021 Every 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.