Willcox, Arizona Weather Forecast Discussion

620
FXUS65 KTWC 230954
AFDTWC
Area Forecast Discussion
National Weather Service Tucson AZ
254 AM MST Tue Sep 23 2025
.SYNOPSIS...Above normal moisture across the region will result
in isolated to scattered rain showers and thunderstorms today and
less so tomorrow. A weather system will bring stronger storms
starting Thursday with impacts gusty winds and risks for flash
flooding.
&&
.KEY MESSAGES...
Today and tomorrow: Isolated thunderstorms and rain showers for
areas south and southeast of Tucson. Less chances and coverage on
Wednesday. Temperatures will be running 3-6 degrees above seasonal
normal.
Thursday-Weekend: A weather system will bring stronger
thunderstorms and high chances for wetting rain showers.
- Increasing risk for flash flooding starting Thursday for areas
  east of Tucson, and expanding westward by Friday, and lasting
  into weekend.
- Expect strong gusty and erratic winds from thunderstorms.
&&
.DISCUSSION...Water vapor imagery has a low pressure center
located west of the San Diego with a minor ridge over Southeast
separating another low pressure center in Colorado. The minor
ridge will keep Southeast Arizona`s temperatures elevated by 3-6
degrees today and through at least Thursday. The upper level
dynamics are not conducive for thunderstorm organization today,
but we do have above normal moisture sitting right on top of us.
We will have to rely on the classic heating to any storm or
shower development. The favorite areas will be in Santa Cruz and
Cochise Counties and along the International Border. Tomorrow,
there will less chances and the mountains will be on the receiving
end of the rain showers.
The big weather story will be hinging on our main player, the San
Diego low pressure center. This system will start to move inland
to continue bringing above normal monsoon moisture and also
tapping into some upper level dry air. This points to a good
signal for thunderstorms so far. The real star of the show will be
the diffluence field that will be over Southeast Arizona starting
on Thursday. Diffluence aloft will bring two main impacts for the
region. 1. This environment will support strong to severe
thunderstorms, leading to gusty erratic winds and hail. EFI shows
88% confidence for CAPE and shear values above climate norms. CAPE
values will generally be 1,000-1,600 J/kg with shear at least 15
kts and possibly up to 25 kts on Thursday and Friday. Plus,
medium range convective forecasts guidance has 15-30% signal for
strong storms. Active day indeed. 2. We will be sitting at
120-150% above normal precipitable water by the end of the week.
Ensemble cluster analysis highlights Friday as one of the wettest
days of the week with rainfall amounts at least 0.25" for
widespread to areas getting up to an inch for a single day. The
south-southwest flow will enhance more rainfall amounts closer to
an inch on the mountains and windward facing sides. Therefore,
there will be increasing risk for flash flooding starting Thursday
for Cochise, Graham, and Greenlee Counties. The risk spreads
westward into Pima, Santa Cruz, and Pinal Counties on Friday and
possibly lasting into Saturday and Sunday.
Ensemble models show the weather system lingering around this
weekend, leading to more chances for rainfall and thunderstorms.
Flash flooding risk will be still elevated, depending on how the
weather system exits. More will tell in the coming days, but for
now, expect a very active weather pattern Thursday through the
weekend. Be storm ready!
On other news, temperature will be down to slightly to
near normal by the weekend.
&&
.AVIATION...Valid through 24/12Z.
SKC this morning then becoming FEW-SCT 8-12k ft AGL by 23/18Z.
Isolated TSRA/SHRA after 23/19Z through 24/02Z, mainly south and
southeast of KTUS. Gusty and erratic winds to around 35 kts will
accompany thunderstorms. Outside of thunderstorms, SFC winds will
light and variable in the morning and again in the overnight
hours. This afternoon, northwest winds less than 12 kts. Aviation
discussion not updated for TAF amendments.
&&
.FIRE WEATHER...Above normal monsoonal moisture will linger today
and tomorrow, providing isolated thunderstorms and rain showers
south and east of Tucson. Min relative humidities will be
bottoming out at 20-30 percent today through Thursday. By
Thursday, a weather system will bring higher chances for wetting
rain showers and stronger thunderstorms through the start of the weekend.
Outside of thunderstorm winds, general winds will be less than 15
mph with the occasional gust up to 20 mph today and tomorrow. The
Gila Valley will have southeasterly breezes in the early Thursday
morning. Expect southerly to southwesterly breezes late Thursday
through Friday due to the incoming weather system. Daytime
temperatures will be running 3-6 degrees above normal through at
least Thursday and dropping to near normal by the weekend.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Strongman
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NWS TWC Office Area Forecast Discussion