Alert archive / Arizona / Special Weather Statements in 2021

Special Weather Statement, NWS Flagstaff, AZ

August 1, 2021

NWS Flagstaff, AZ issued this special weather statement at Aug 1, 2021, 3:21 PM MST. It was in force for 24 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 1, 2021, 3:21 PM MST (22:21 UTC)
Expired
Aug 1, 2021, 3:45 PM MST
In force
24 min
Issued by
NWS Flagstaff, AZ

The radar

The Flagstaff radar (KFSX), 65 km from the middle of the area, began a volume at 22:22 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, 10.4 hours before the alert went out and 62 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 2021-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 74 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 2021-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 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
74 J/kg
Mixed-layer CIN
-65 J/kg
Mixed-layer LCL
1273 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

660 
WWUS85 KFGZ 012221
SPSFGZ

Special Weather Statement
National Weather Service Flagstaff AZ
321 PM MST Sun Aug 1 2021
 
AZZ012-015-012245-
Little Colorado River Valley in Coconino County-Western Mogollon Rim-
321 PM MST Sun Aug 1 2021

...A LINE OF THUNDERSTORMS WILL GRADUALLY MOVE SOUTHEAST ALONG I-40 
BETWEEN TWIN ARROWS AND TWO GUNS UNTIL 345 PM ARIZONA TIME...

At 319 PM Arizona time, Doppler radar was tracking a line of strong 
thunderstorms moving east of Twin Arrows along I-40.

Pea size hail and winds in excess of 30 mph will be possible with
these storms.

Locations impacted include...
Two Guns, Rimmy Jims, Twin Arrows, and Meteor Crater. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3529 11105 3492 11095 3498 11125 3531 11131
TIME...MOT...LOC 2219Z 307DEG 6KT 3525 11126 3501 11121 

$$

TM

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 5:22 PM MSTAreal Flood AdvisoryFGZYavapai113 min
Jul 31, 6:08 PM MSTAreal Flood AdvisoryFGZApache, Navajo3 hr
Aug 1, 12:03 PM MSTSpecial Weather StatementFGZ27 min
Aug 1, 12:15 PM MSTSpecial Weather StatementFGZ30 min
Aug 1, 12:53 PM MSTSpecial Weather StatementFGZCoconino22 min
Aug 1, 1:08 PM MSTSpecial Weather StatementFGZ22 min
Aug 1, 1:14 PM MSTSpecial Weather StatementFGZ31 min
Aug 1, 1:30 PM MSTSpecial Weather StatementFGZNavajo30 min
Aug 1, 1:38 PM MSTSpecial Weather StatementFGZCoconino22 min
Aug 1, 1:53 PM MSTSpecial Weather StatementFGZ37 min
Aug 1, 2:03 PM MSTSpecial Weather StatementFGZNavajo27 min
Aug 1, 2:26 PM MSTSpecial Weather StatementFGZNavajo34 min
Aug 1, 2:55 PM MSTSpecial Weather StatementFGZ35 min
Aug 1, 3:12 PM MSTSpecial Weather StatementFGZ33 min
Aug 1, 3:15 PM MSTSpecial Weather StatementFGZ30 min
Aug 1, 3:58 PM MSTFlash Flood WarningFGZGila, Navajo3 hr
Aug 1, 4:18 PM MSTAreal Flood AdvisoryFGZCoconino3 hr
Aug 1, 4:24 PM MSTSpecial Weather StatementFGZ51 min
Aug 1, 4:38 PM MSTSevere Thunderstorm WarningFGZApache, Navajo37 min
Aug 1, 4:51 PM MSTFlash Flood WarningFGZGila, Navajo3 hr
Aug 1, 4:52 PM MSTFlash Flood Warning Considerable damage threatFGZApache, Coconino, Navajo3 hr

Nearby

Special Weather Statements in Arizona, 2021Every special weather statement 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.