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, 2:55 PM MST. It was in force for 35 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, 2:55 PM MST (21:55 UTC)
Expired
Aug 1, 2021, 3:30 PM MST
In force
35 min
Issued by
NWS Flagstaff, AZ

The radar

The Cedar City radar (KICX), 210 km from the middle of the area, began a volume at 21:55 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, 9.9 hours before the alert went out and 164 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°0°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.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Flagstaff, AZ wrote its last area forecast discussion before this special weather statement went out at Aug 1, 2:23 PM MST, 32 minutes earlier.

Area forecast discussion, Aug 1, 2:23 PM MST, 32 minutes before
Area Forecast Discussion
National Weather Service Flagstaff AZ
223 PM MST Sun Aug 1 2021

.SYNOPSIS...Scattered thunderstorms will continue through this
evening before diminishing overnight. Expect decreasing
thunderstorm chances Monday with a drying and warming trend in
store Tuesday through Thursday as high pressure strengthens over
the area.

&&

.DISCUSSION...Scattered thunderstorms have developed this
afternoon. The most pronounced activity has been across eastern
Coconino, Navajo and Apache Counties with lesser activity to the
west. A few of the stronger storms have been producing heavy
rainfall and gusty outflow winds. Locally heavy rain and training
storms leading to flash flooding will again be the main concern
today. Scattered storms will continue over Navajo and Apache
counties this evening before ending overnight.

A downturn in thunderstorms is still expected to begin on Monday
as strong high pressure over the Rocky Mountains builds westward
and over the southwestern states. This will lead to a drier
northwest flow over Arizona Monday, causing thunderstorm chances
to retreat to the east. We'll still see isolated to scattered
activity, but much less than the past several days. Lightning,
gusty winds and locally heavy rain will be the main storm threats.

Thunderstorm chances will continue the downward trend through the
middle of the week with only isolated activity expected Tuesday
through Thursday. In addition, the building high pressure and much
more daytime sun will allow temperatures to rise above average.
The lower elevations of the Grand Canyon will near heat warning
criteria of 110F by Wednesday/Thursday.

The high pressure ridge axis is forecast to slide east of Arizona
on Friday opening the door again to a northward push of monsoon
moisture. Operational and ensemble models are in agreement with
the return of moisture and thunderstorm chances Friday through
next weekend.

&&

.AVIATION...For the 00Z package...Mainly VFR conditions will
prevail. Scattered storms will continue through this evening,
mainly along and north of a KFLG-KSOW line. Periods of MVFR/IFR
conditions and gusty, erratic winds will occur in and around
thunderstorms. Storm activity will gradually diminish after 03Z.
Another round of isolated to scattered storms will develop after
18Z Mon. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Scattered thunderstorms with locally heavy rain
will continue this evening. Look for decreasing thunderstorm
chances Monday and Tuesday with a drying and warming trend.

Wednesday through Friday...Warm and mainly dry conditions continue
through midweek with light winds. Moisture and storm chances
return Friday.

&&

.FGZ WATCHES/WARNINGS/ADVISORIES...NONE.

&&

PUBLIC...MCT
AVIATION...MCT
FIRE WEATHER...MCT

For Northern Arizona weather information visit
weather.gov/flagstaff

In the hours before

Special weather statement, Aug 1, 1:30 PM MST, 1 hour 25 minutes before
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Special weather statement, Aug 1, 1:38 PM MST, 1 hour 17 minutes before
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Special weather statement, Aug 1, 1:53 PM MST, 1 hour 2 minutes before
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Special weather statement, Aug 1, 2:03 PM MST, 52 minutes before
Special Weather Statement
National Weather Service Flagstaff AZ
303 PM MDT Sun Aug 1 2021

AZZ012-013-012130-
Little Colorado River Valley in Coconino County-Little Colorado River
Valley in Navajo County-
303 PM MDT Sun Aug 1 2021

...A STRONG THUNDERSTORM WILL CONTINUE TO AFFECT THE WINSLOW AREA
UNTIL 230 PM ARIZONA TIME...

At 202 PM Arizona time, Doppler radar was tracking a strong
thunderstorm near Winslow, moving north at 15 mph.

Half inch hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Winslow.
I-40 near Winslow.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3492 11074 3498 11091 3522 11087 3519 11061
TIME...MOT...LOC 2102Z 197DEG 11KT 3504 11079

TM
Special weather statement, Aug 1, 2:26 PM MST, 29 minutes before
Special Weather Statement
National Weather Service Flagstaff AZ
326 PM MDT Sun Aug 1 2021

AZZ012-013-012200-
Little Colorado River Valley in Coconino County-Little Colorado River
Valley in Navajo County-
326 PM MDT Sun Aug 1 2021

...A STRONG THUNDERSTORM WILL CONTINUE TO MOVE NORTH OF WINSLOW
THROUGH 300 PM ARIZONA TIME...

At 224 PM Arizona time, Doppler radar was tracking a strong
thunderstorm near Winslow, moving north at 10 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

This storm will remain over mainly rural areas north of Winslow and
I-40.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3504 11071 3506 11088 3527 11088 3524 11059
TIME...MOT...LOC 2124Z 190DEG 10KT 3509 11078

TM
Special weather statement, Aug 1, 2:55 PM MST, 0 minutes before
Special Weather Statement
National Weather Service Flagstaff AZ
355 PM MDT Sun Aug 1 2021

AZZ009-039-012230-
Black Mesa Area-Northeast Plateaus and Mesas Hwy 264 Northward-
355 PM MDT Sun Aug 1 2021

...A STRONG THUNDERSTORM WILL CONTINUE TO DEVELOP NEAR KAIBITO
THROUGH 430 PM NAVAJO NATION TIME...

At 353 PM MDT, Doppler radar was tracking a strong thunderstorm east
of Kaibito, or 36 miles northeast of Tuba City, moving northeast at
10 mph.

Half inch hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Inscription House Landing Strip, Shonto, and Kaibito.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3637 11092 3641 11111 3680 11114 3665 11049
TIME...MOT...LOC 2153Z 211DEG 8KT 3657 11090

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, 3:12 PM MSTSpecial Weather StatementFGZ33 min
Aug 1, 3:15 PM MSTSpecial Weather StatementFGZ30 min
Aug 1, 3:21 PM MSTSpecial Weather StatementFGZ24 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.