Special Weather Statement, NWS Tucson, AZ

Area Forecast Discussion
National Weather Service Tucson AZ
234 AM MST Thu Sep 30 2021

.SYNOPSIS...A weather system continues to influence the region today
providing more chances for showers and thunderstorms. Afternoon
temperatures will remain cooler than average during much of the
forecast. Early next week another weather system may bring rain to
the region again.

&&

.DISCUSSION...Radar is currently scanning showers and thunderstorms
over Pinal and eastern Pima County, slowly pushing into Graham
County. The most robust activity overnight was across Pinal County
and western Pima, including a few severe or near severe storms.
Storms have since relaxed in the last hour or so, albeit still
generating lightning and pockets of heavier rainfall. This is all
being driven by an elongated upper-low centered over Utah extending
a shortwave trough axis into central Arizona. Cooling aloft was able
to produce a decent amount of instability despite the lack of solar
heating. The current cluster of precipitation will continue to
gradually track east with the shortwave, but models show another
round of storms developing this afternoon. Cochise County looks to
be the most active area, but precip chances still reach as far west
as Tucson, decreasing from there as drier air pushes in. High
temperatures should be suppressed 5-10 degrees below seasonal
normals.

A slight chance of rainfall remains in the White Mountains on
Friday, becoming dry area wide this weekend. Temperatures gradually
rise back near normal by Sunday/Monday. However, another round of
showers and thunderstorms looks to develop early next week. This is
caused by yet another upper-low, now originating over the Pacific
Ocean west of California/Baja. Southerly flow across our region will
draw up moisture and the low is progged to eventually get pulled
into the mean trough and pass to our north. There's a fair amount of
uncertainty regarding what areas will have the best chance for rain,
but ensemble guidance focuses in on the Tuesday afternoon/evening
timeframe.

&&

.AVIATION...Valid through 01/12Z.
Isolated to scattered showers and thunderstorms continuing through
at least 01/04Z with cigs AOA 8-12kft MSL. Thereafter, expect
clearing from west to east with showers and thunderstorms ending.
Surface winds generally southwest to west at less than 12kts except
strong and gusty near showers and thunderstorms. Aviation not
updated for TAF amendments.

&&

.FIRE WEATHER...Isolated to scattered showers and thunderstorms will
continue through today. The best chances mainly from Tucson
eastward. Rainfall chances decrease temporarily heading into the
weekend before returning early next week. High temperatures remain
below normal until warming to near seasonal levels toward Sunday.
The 20-foot winds will generally be less than 15 mph.

&&

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

&&

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Special Weather Statement
National Weather Service Tucson AZ
1257 AM MST Thu Sep 30 2021

AZZ505-506-300830-
Southeast Pinal County including Kearny/Mammoth/Oracle-South Central
Pinal County including Eloy/Picacho Peak State Park-
1257 AM MST Thu Sep 30 2021

...A strong thunderstorm will impact portions of south central Pinal
County through 130 AM MST...

At 1257 AM MST, Doppler radar was tracking a strong thunderstorm 16
miles east of Picacho Peak State Park, or 20 miles north of Marana,
moving east at 25 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.

This storm will remain over mainly remote areas of south central
Pinal County.

This includes Route 79 between mile markers 98 and 113.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

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 3259 11120 3277 11126 3287 11099 3264 11088
TIME...MOT...LOC 0757Z 253DEG 22KT 3271 11114

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

Special Weather Statement
National Weather Service Tucson AZ
321 AM MST Thu Sep 30 2021

AZZ507-508-513-301100-
Upper San Pedro River Valley including Sierra
Vista/Benson-Dragoon/Mule/Huachuca and Santa Rita Mountains including
Bisbee/Canelo Hills/Madera Canyon-Eastern Cochise County Below 5000
Feet including Douglas/Willcox-
321 AM MST Thu Sep 30 2021

...A strong thunderstorm will impact portions of northwestern Cochise
County through 400 AM MST...

At 320 AM MST, Doppler radar was tracking a couple of strong
thunderstorms about 10 miles north of Benson, moving northeast 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.

These storms will remain over mainly remote areas of northwestern
Cochise County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3199 11029 3221 11041 3233 11022 3209 11005
TIME...MOT...LOC 1020Z 234DEG 8KT 3211 11028

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