489
FXUS65 KTWC 272148
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
248 PM MST Fri Jun 27 2025

SYNOPSIS...Afternoon and evening chances for showers and
thunderstorms continue this afternoon south and east of Tucson,
mainly along the International border east of Nogales and closer to
the New Mexico border. Temperatures become hotter this weekend as
conditions dry out. Monsoonal moisture is expected to increase next
week with increasing precipitation chances, especially the second
half of the week including around Independence Day.

&&

.KEY MESSAGES...

-Temperatures will be on the increase this weekend, peaking Monday
with highs of 108 to 112 degrees in the deserts including Tucson and
Upper Gila River Valley. An Extreme Heat Warning is in effect Monday
for these locales.

-A few thunderstorms this afternoon mainly in Cochise County then
drier conditions return this weekend with only a slight chance of
thunderstorms along the Int`l border in Cochise County tomorrow.

-Monsoon 2025 will swing into full gear next week. The heat will be
on the downward trend by midweek as moisture will be on the
increase. Initial monsoon storm threats will be focused more on
gusty winds, but will quickly transition more towards heavy rain and
flash flooding threats as the week progresses. This includes
Independence Day.

.DISCUSSION...Doppler radar this afternoon showed isolated showers
and a few thunderstorms again that developed east and south of
Tucson across higher terrain areas. Isolated shower and thunderstorm
activity will continue this afternoon with the best chances
consolidated along and near the AZ/NM and International border in
Cochise, Graham, Greenlee, and Santa Cruz counties.

Looking at the upper pattern, high pressure is gradually returning
to the Desert Southwest with further amplification expected this
weekend. The higher pressure building in will generally result in
warmer, drier, and subsiding air aloft with decreasing chances for
precipitation. A slight chance (10-15%) for an isolated shower or
thunderstorm will remain along the International border in Cochise
county tomorrow as well as the White Mountains. However, the best
chances (15-30%) will remain to our east in New Mexico and south in
Sonora MX.

Otherwise, temperatures will be on the rise this weekend as a result
of the high pressure and are expected to peak on Monday afternoon.
An Extreme Heat Warning is in effect for Monday for the deserts of
SE Arizona and Upper Gila River Valley with highs 108 to 112
degrees. Expect a bit of an uptick in thunderstorm chances Monday
afternoon and evening, mainly from Tucson eastward. Gusty outflow
winds would be the primary threat which could also result in reduced
visibility from blowing dust.

As the rest of next week progresses, a steady increase in moisture
from the south and east is expected as the subtropical high
positions itself more towards the Four Corners with troughing near
the southern California coast. This scenario will help usher in well
above normal moisture by mid to late next week with a quick
transition from our typical early season monsoon threats including
gusty winds and blowing dust to more of a heavy rain/flash flood
threat with wind potential as well by around next Thursday and
Independence Day. With the increased moisture, temperatures will
drop back down to near normal by Wednesday and then below normal
late next week. Looks like Monsoon 2025 may be off to an abrupt
start. Stay tuned!

&&

.AVIATION...Valid through 29/00Z.
SCT to BKN clouds at around 10-13k ft AGL mainly along the Int`l
border from KOLS eastward and along the AZ/NM border gradually
decreasing in coverage after 28/07Z. For these areas, isold
-SHRA/TS diminishing after 28/03Z. Isold gusts up to 40 kts nr
-TSRA otherwise winds light and under 12 kts with an ocnl aftn gust
up to 20 kts. Overnight, winds will remain below 8 kts vrbl in
direction. Tomorrow afternoon winds will be NWLY remaining under 12
kts with SCT clouds at around 10-13k ft AGL. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...Isolated showers and thunderstorms this afternoon
mainly along the AZ/NM border and Int`l border from Nogales
eastward. Minimum relative humidities from 10 to 20 percent, with a
drying and warming trend this weekend. Winds generally light and
under 15 mph with isolated gusts up to 45 mph under any
thunderstorms Moisture will be on the rise next week with widespread
rain chances by mid to late next week. Initially, the main threats
will be gusty winds early in the week, but that will transition to
both a wind and rain/flooding threat late next week.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Warning from 10 AM to 8 PM MST Monday for AZZ501-502-
504>506-509.

&&

$$

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