Alert archive / Arizona / Special Weather Statements in 2021

Special Weather Statement, NWS Tucson, AZ

August 28, 2021Pinal County, Arizona

NWS Tucson, AZ issued this special weather statement at Aug 28, 2021, 5:12 PM MST for Pinal County, Arizona. It was in force for 48 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 28, 2021, 5:12 PM MST (00:12 UTC)
Expired: Aug 28, 2021, 6:00 PM MST
In force: 48 min
Issued by: NWS Tucson, AZ
Hail: 0.50 in
Wind: 50

County Pinal County, AZ

The radar

The Phoenix radar (KIWA), 86 km from the middle of the area, began a volume at 00:13 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

Tuscon, AZ (KTUS), launched 00:00Z, 0.2 hours before the alert went out and 96 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: 68 J/kg
Mixed-layer CIN: -165 J/kg
Mixed-layer LCL: 2343 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 113 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 Tucson, AZ wrote its last area forecast discussion before this special weather statement went out at Aug 28, 3:30 PM MST, 1 hour 42 minutes earlier.

Area forecast discussion, Aug 28, 3:30 PM MST, 1 hour 42 minutes before

Area Forecast Discussion
National Weather Service Tucson AZ
330 PM MST Sat Aug 28 2021

.SYNOPSIS...
Scattered afternoon showers and storms are expected each afternoon
and evening this weekend. Early next week an increase in storm
activity is forecast as tropical moisture moves into the area and
lingers through mid to late in the week. Concerns for heavy
rainfall leading to flash flooding will also rise as a result.

&&

.DISCUSSION...Scattered thunderstorms developing as expected this
afternoon. Precipitable water values range from 1.2 inches east to
1.5 inches west. Easterly to southeasterly steering flow for
storms with a decent shear environment for our corner of the
state. Watch for isolated strong to near severe thunderstorms in
and amongst the garden variety pulse storms, with some
organized outflow pushing toward the lower deserts. We'll see how
things hold together for Tucson Metro over the next few hours and
if we end up kicking up some dusty outflows. A chance of
thunderstorms will continue through the weekend.

Next we watch for deeper surge activity pushed up the gulf ahead
of hurricane Nora. A convective complex that pushed from Sonora
into the northern Gulf already assisted with a relatively deep
moisture push through Yuma with southerly flow stacked 6k feet
deep and the Yuma dewpt jumping 20 degrees over the past 24 hours.
This will likely weaken before we see something stronger early in
the new week.

Current Nora projections bring her up very near the western coast
of Mexico over the next 72 hours. She may be able to hang on to
hurricane status as this happens, but not much more than that this
close to the coast. A trajectory like this often ends up with the
tropical system decoupling over southern Sonora with just mid
level remnants making it across the AZ border, but we'll have to
see. A bit more to the east and we could see it shearing apart
earlier than expected. A bit more to the west and it should hang
on through the central Gulf.

It is, however, becoming increasingly likely that we will see a
deep and sustained surge through the Gulf of California as well as
inland ahead of the storm. NAEFS and ECMWF ensemble means suggest
an integrated water vapor transport maximum Monday night into
Tuesday, with maximum precipitable water values Wednesday in
excess of 1.75 inches. For SE AZ, our best precip chances (with
possible heavy rain threat) could end up being multiple periods
from Monday afternoon through most of the week. Tricky though. We
get too much moisture and we could see a few days of light to
moderate rainfall with storm totals in the 1 to 2 inch range, but
not with rainfall rates that would suggest flash flooding. Or we
could have multiple periods where we see twice as much storm total
rainfall accompanied by flash flood threats. Or anything in
between. Tropical systems (especially weaker ones like Nora) are a
tough call.

&&

.AVIATION...Valid through 30/00Z.
FEW-SCT clouds at 8k-12k ft MSL (locally BKN during the afternoon
and evening hours, especially east and south of KTUS) thru the
forecast period. ISOLD-SCT SHRA/TSRA thru 29/05Z and then again aft
30/19Z. MVFR conditions and mountain-top obscurations near TSRA,
along with wind gusts up to 45 kts. Otherwise, SFC wind favoring an
ELY/SELY direction and generally less than 12 kts. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Isolated to scattered showers and thunderstorms are
expected for much of the forecast area through Monday. Deeper
moisture will then overspread the area Tuesday through Thursday of
next week as moisture associated with the remnants of Nora shifts
northward. This will result in increasing precipitation chances mid
to late next week across southeast Arizona, with potentially heavy
rainfall at times. 20-foot winds will generally be less than 15 mph
when not influenced by thunderstorms gusts.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&

Public...Meyer
Aviation...Zell
Fire Weather....Zell

Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson

In the hours before

Special weather statement, Aug 28, 3:49 PM MST, 1 hour 23 minutes before

Special Weather Statement
National Weather Service Tucson AZ
349 PM MST Sat Aug 28 2021

AZZ503-513-282330-
Dragoon/Mule/Huachuca and Santa Rita Mountains including
Bisbee/Canelo Hills/Madera Canyon-Upper Santa Cruz River and Altar
Valleys including Nogales-
349 PM MST Sat Aug 28 2021

...A strong thunderstorm will impact portions of north central Santa
Cruz County through 430 PM MST...

At 348 PM MST, Doppler radar was tracking a strong thunderstorm near
Tubac, moving west at 10 mph.

HAZARD...Winds in excess of 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Tubac, Tumacacori and Amado.

This includes Interstate 19 between mile markers 18 and 27.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3152 11114 3168 11115 3171 11089 3161 11088
TIME...MOT...LOC 2248Z 069DEG 9KT 3164 11100

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

Zell

Special weather statement, Aug 28, 4:06 PM MST, 1 hour 6 minutes before

Special Weather Statement
National Weather Service Tucson AZ
406 PM MST Sat Aug 28 2021

AZZ506-507-509-511-514-282345-
Upper Gila River and Aravaipa Valleys including Clifton/Safford-Santa
Catalina and Rincon Mountains including Mount
Lemmon/Summerhaven-Upper San Pedro River Valley including Sierra
Vista/Benson-Southeast Pinal County including
Kearny/Mammoth/Oracle-Galiuro and Pinaleno Mountains including Mount
Graham-
406 PM MST Sat Aug 28 2021

...A strong thunderstorm will impact portions of west central Graham
and southeastern Pinal Counties through 445 PM MST...

At 405 PM MST, Doppler radar was tracking a strong thunderstorm 8
miles southeast of Aravaipa Canyon Wilderness, or 12 miles northeast
of Mammoth, moving west at 15 mph.

HAZARD...Wind gusts up to 50 mph and half inch hail, along with
         heavy rain.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Oracle, Mammoth, San Manuel, Dudleyville, Aravaipa Canyon Wilderness,
Biosphere 2 and Klondyke.

This includes Route 77 between mile markers 98 and 133.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3291 11029 3262 11042 3257 11086 3301 11075
TIME...MOT...LOC 2305Z 090DEG 13KT 3280 11045

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH

Meyer

Local storm report, Aug 28, 4:14 PM MST, 58 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
414 PM MST SAT AUG 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0340 PM     TSTM WND DMG     13 SSE TUCSON           32.03N 110.77W
08/28/2021                   PIMA               AZ   LAW ENFORCEMENT

            POWER POLE DOWN AT HOUGHTON RD AT DAWN RD.

&&

Local storm report, Aug 28, 4:19 PM MST, 53 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
419 PM MST SAT AUG 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0400 PM     FLASH FLOOD      1 S NOGALES             31.34N 110.93W
08/28/2021                   SANTA CRUZ         AZ   PUBLIC

            WEBCAM IMAGERY OF NOGALES WASH DEPICTING
            WASH OVERTOPPING ITS BANKS.

&&

Local storm report, Aug 28, 4:58 PM MST, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
458 PM MST SAT AUG 28 2021

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0443 PM     FLOOD            14 SE TUCSON            32.05N 110.72W
08/28/2021                   PIMA               AZ   TRAINED SPOTTER

            WATER RUNNING ACROSS ROADS NEAR AND WITHIN
            VAIL INCLUDING VAIL RD AND EAST DON ROAD.

&&

CC

Special weather statement, Aug 28, 5:12 PM MST, 0 minutes before

Special Weather Statement
National Weather Service Tucson AZ
512 PM MST Sat Aug 28 2021

AZZ505-506-290100-
Southeast Pinal County including Kearny/Mammoth/Oracle-South Central
Pinal County including Eloy/Picacho Peak State Park-
512 PM MST Sat Aug 28 2021

...A strong thunderstorm will impact portions of northeastern Pinal
County through 600 PM MST...

At 512 PM MST, Doppler radar was tracking a strong thunderstorm near
Kearny, or near Hayden, moving west at 15 mph.

HAZARD...Wind gusts up to 50 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Kearny, Dudleyville and Kelvin.

This includes the following highways...
 Route 77 between mile markers 129 and 134.
 Route 177 between mile markers 139 and 158.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3299 11078 3298 11078 3303 11073 3306 11072
      3307 11073 3308 11069 3294 11058 3285 11094
      3310 11117 3325 11095
TIME...MOT...LOC 0012Z 071DEG 12KT 3305 11084

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH

GL

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 28, 5:03 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima, Pinal	117 min
Aug 28, 5:20 PM MST	Severe Thunderstorm Warning	TWC	Pinal	40 min
Aug 28, 6:31 PM MST	Severe Thunderstorm Warning	TWC	Pima	44 min
Aug 28, 6:47 PM MST	Special Weather Statement	TWC	Pinal	43 min
Aug 28, 7:01 PM MST	Areal Flood Warning	TWC	Pima, Pinal	3 hr
Aug 28, 7:14 PM MST	Severe Thunderstorm Warning	TWC	Pima	61 min
Aug 28, 7:41 PM MST	Flash Flood Warning	TWC	Pima	109 min
Aug 28, 8:03 PM MST	Severe Thunderstorm Warning	TWC	Pima	57 min
Aug 28, 8:25 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	2 hr
Aug 29, 2:32 PM MST	Special Weather Statement	TWC	Cochise	43 min
Aug 29, 3:53 PM MST	Special Weather Statement	TWC	Pima	37 min
Aug 29, 4:23 PM MST	Areal Flood Advisory	TWC	Pima	112 min
Aug 29, 4:46 PM MST	Special Weather Statement	TWC	Pinal	59 min

Nearby

Special Weather Statements in Arizona, 2021 Every 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.