463
FXUS65 KTWC 302042
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
142 PM MST Sat Aug 30 2025

.SYNOPSIS...A low-grade monsoon day is expected today. Any
thunderstorm chances are mainly in far southern and eastern
locations of southeastern Arizona. Moisture and thunderstorm
chances begin to increase again Sunday through next week, with day
to day variability. High temperatures will be near normal through
early next week, lowering to several degrees below normal the
second half of the week.

&&

.DISCUSSION...Satellite shows cumulus over the higher terrain with
a couple weak echoes over the Chiricahuas and southern Greenlee
County. Northerly mid-level flow has pushed moisture to the
international border and AZ/NM border. This is evidenced in the
18Z KTWC sounding from this morning with dry air in the 600-350
mb layer. As a result storm chances will mainly be confined to
Cochise and Santa Cruz counties this afternoon. Best chances will
be over the Chiricahuas.

Sunday the center of the high pushes a little further north
resulting in easterly/northeasterly mid-level flow over most of
southeast Arizona. This will allow moisture to increase over areas
east and south of Tucson with isolated to scattered storm
coverage expected. Tucson will be on the western edge of
thunderstorm chances. Steering winds will have a northeast
component over Graham and Greenlee Counties, which will allow
storms to move off the White Mountains and into the Gila River
Valley and I-10 corridor in Cochise County. The HREF is signaling
the potential for strong outflow winds in this area with
probabilities for winds in excess of 30 kts 70 percent. Locally
heavy rainfall will also be a threat south and east of Tucson.

Easterly to southeasterly flow continues during the work week
which will keep storm chances alive each day this week. Although
for the first half of the week the better moisture looks to be
from Tucson east, then switches to Tucson westward as slightly
dryer air moves in for eastern areas Wednesday and Thursday.
Monday looks to be a fairly active day as models show a weak
easterly wave moving through Sonora. This feature increases 500 mb
flow to 20-30 kts across much of the area with the strongest winds
along the international border. This along with the extra
synoptic scale lift could lead to strong to severe storms Monday
afternoon and evening.

For the last part of the work week southeast Arizona may see an
influx of tropical moisture. Models hint at a tropical system
potentially off the west coast of Baja by this weekend. NHC shows
an 80 percent of tropical storm formation over the next 7 days,
but with great uncertainty in the track of any storm that does
form once it passes 20N. Something to monitor as the end of the
work week approaches.

&&

.AVIATION...Valid through 01/00Z.
Cloud bases SCT-BKN 8k-11k ft and isolated to scattered showers
and thunderstorms mainly south and east especially near KDUG this
afternoon. Just cirrus clouds today further north/west through
KTUS. Expect an increase in thunderstorm chances Sunday afternoon
at KOLS and KDUG with KTUS on the western periphery of storm
chances. Winds mainly light and terrain driven with strong gusts
30-40 kts in the vicinity of any TSRA. Aviation discussion not
updated for TAF Amendments.

&&

.FIRE WEATHER...A low-grade monsoon day is expected today with
increasing chances in southern and eastern locations tomorrow.
Daily chances will continue through the upcoming week, with day to
day variability. High temperatures will be near to slightly above
normal through the weekend, with readings lowering to several
degrees below normal by the second half of the work week. Winds
over the next several days will generally remain less than 15 mph
with typical afternoon gustiness. Min RHs will be in the 20-30
percent range in the lower elevations and 35-45 percent in the
mountains.

&&

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

$$

Hardin

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