Special Weather Statement, NWS Tucson, AZ

Area Forecast Discussion
National Weather Service Tucson AZ
302 PM MST Mon Oct 4 2021

.SYNOPSIS...Increasing chances for showers and thunderstorms are
expected today into tomorrow as a weather system passes across
Arizona. Drier weather will follow for Wednesday and Thursday with
temperatures remaining within a few degrees of seasonal normals.
Another weather system is possible over the weekend or early next
week.

&&

.DISCUSSION...A low pressure system near the northern Baja coast
has drawn up enough moisture for a few showers with isolated
thunderstorms possible this afternoon. The 12Z KTWC sounding was
up to 3/4 of an inch precipitable water, and current satellite
TPW estimates are pushing toward 1 inch. Weak dynamics this
afternoon so don't expect much in the way of heavy rain. Over the
past few hours it looks like the low is following the script and
wobbling in this general direction. As a strong trough continues
to dig down the west coast, it will pick up speed and be pushing
through southern California by tomorrow morning. That should keep
our chance of showers going overnight with a few embedded
thunderstorms.

The low will open up and shear northeastward on the eastern flank
of the trough Tuesday, with the remnant open wave in Utah tomorrow
night. It will likely entrain some of the dry air currently south
of the low into portions of our area tomorrow, primarily near and
west of Tucson. Good shear and convective potential tomorrow, with
the best moisture/dynamics couplet coming together east and north
of Tucson. Those are the locations to watch for best chances of
strong storms with brief heavy rain tomorrow.

As the strong trough continues to deepen down the west coast with
the significant southern branch split, high pressure will build
from central to northern Mexico Wednesday and Thursday. Our
temperatures will run a few degrees above climo as this happens
(since normals drop quickly through the months of October and
November).

The more active pattern will continue through mid month, with a
glancing blow from the next system over the weekend potentially
setting the table for stronger and cooler system next week. We
might end up with our first freeze in coldest eastern valleys
around the middle or second half of next week.

&&

.AVIATION...Valid through 06/00Z.
SCT-BKN clouds at 10k-14k ft MSL and BKN-OVC layered clouds above,
along with ISOLD-SCT -SHRA/-TSRA thru the forecast period. Local
MVFR conditions, mountaintop obscurations and wind gusts to 40 kts
near the stronger TSRA. Otherwise, SFC wind less than 12 kts and
favoring a SLY/SELY direction. Aviation not updated for TAF
amendments.

&&

.FIRE WEATHER...There will be a chance of showers and thunderstorms
through Tuesday evening, clearing from west to east Tuesday night.
Much of the forecast area has a chance for wetting rain during this
period, with another slight chance for showers north/northeast of
Tucson Thursday night and Friday. 20-foot winds will be less than 15
mph through Thursday, strengthening over the weekend especially to
the east of Tucson.

&&

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

&&

Meyer/Zell

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Special Weather Statement
National Weather Service Tucson AZ
438 PM MST Mon Oct 4 2021

AZZ509-510-050015-
Upper Gila River and Aravaipa Valleys including Clifton/Safford-White
Mountains of Graham and Greenlee Counties including Hannagan Meadow-
438 PM MST Mon Oct 4 2021

...A strong thunderstorm will impact portions of central Graham
County through 515 PM MST...

At 438 PM MST, Doppler radar was tracking a strong thunderstorm over
Safford Regional Airport, or near Safford, moving northwest at 20
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...
Safford, Thatcher, Solomon, Safford Regional Airport, Pima and
Central.

This includes the following highways...
 Route 70 between mile markers 314 and 347.
 Route 191 between mile markers 118 and 120.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3288 10951 3274 10964 3290 10995 3311 10975
TIME...MOT...LOC 2338Z 129DEG 16KT 3286 10965

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

GL