534
FXUS65 KTWC 022035
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
135 PM MST Thu Oct 2 2025

.SYNOPSIS...Dry conditions will prevail into next week. Afternoon
high temperatures will warm to 7 to 9 degrees above normal today and
Friday, before cooling down to near normal levels this weekend.
Breezy southwest winds are expected this weekend as a system moves
to our north. High temperatures warm again to 3 to 5 degrees above
normal next week.

&&

.DISCUSSION...The large scale pattern has high pressure centered
over northern Mexico into southern New Mexico, with a ridge over the
southwestern United States and a Pacific storm system off the
Washington coast. The Pacific low will dive southeast into central
Nevada by late Friday as the high pressure ridge shifts east into
Texas and the Gulf coast. The low will then shift east across the
Great Basin over the weekend, with zonal flow across the desert
southwest. By early next week, the flow aloft turns southwesterly
across the region.

For today and Friday, above normal high temperatures are forecast,
with highs topping out 7-9 degrees above seasonal averages. High
temperatures will be in the upper 90s to right around 100 degrees
from Tucson westward. NBM probabilities indicate a 10% chance for
100 degrees at Tucson airport today and 15% on Friday. Blended total
precipitable water imagery shows PWAT`s currently in the 0.40" to
0.60" range, with higher amounts over an 1" across central/northern
Sonora Mexico. The models indicate some of this deeper moisture will
get pulled northward in advance of the approaching storm system and
trough tonight into Friday. At this time PWATs are forecasted to
increase into the 0.70" to 0.90" range across the eastern half of
southeast Arizona, which would bring an increase in mid-level cloud
cover from Tucson east. At this time no precipitation is forecasted
by the NBM. Depending upon the evolution of the moisture plume and
trough axis this will be something to keep an eye on for tomorrow,
mainly east of Tucson.

As the storm system tracks north of the region over the weekend,
temperatures cool down to near seasonal normals with highs in the
upper 80s to lower 90s from Tucson westward and highs in the 80s
across Santa Cruz, Cochise and Graham counties. This system will
also bring gusty southwest winds to the area especially Saturday
afternoon. Wind speeds will generally be 12-17 mph with gusts to 25-
30 mph from Tucson eastward. Peak wind gusts on Saturday will be
between 30-35 mph across portions eastern Santa Cruz and Cochise
counties.

By early next week, the storm system will track east into the
central plains and southwest flow aloft will prevail across the
region. This will lead to warmer temperatures with highs 3-5 degrees
above normal.

For mid to late next week, still quite a bit of uncertainty in
regard for the potential of tropical moisture advecting into the
area. Deterministic runs are highly variable and differ with each
run. NBM has significantly lower precipitation chances and amounts
versus yesterday. However, the latest 6-10 day (Oct 7-11) and 8-10
day (Oct 9-15) precipitation outlooks are leaning above normal (50-
70%) across the area. It will all come down to the track of the
disturbance currently centered off the central Mexican coastline and
the position of west coast trough next week. Latest grids have
slight chance pops for both next Wednesday and Thursday.

&&

.AVIATION...Valid through 04/00Z.
Clear skies/SKC conditions across most of southeast Arizona thru
03/02Z, with FEW-SCT clouds at 10k-12k ft AGL from KTUS east aft
03/02Z. SFC wind variable and terrain driven at less than 10 kts
between 03/04Z and 03/17Z. SWLY/WLY SFC wind at 6-12 kts and a few
gust to around 18 kts until 03/04Z and again aft 03/17Z. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Dry conditions will prevail across southeast Arizona
into at least early next week. 20-foot winds will be 15 mph or less
and terrain driven through Friday. A storm system will then move to
our north this weekend resulting in increasing southwesterly winds.
20-foot winds will be 12-17 mph and gusts to around 30 mph Saturday
and Sunday, with the strongest winds southeast of Tucson across
portions of Santa Cruz and Cochise counties. Min RH values in the
valleys will be in the 15-30 percent range through Friday, lowering
to 12-20 percent over the weekend. RH values in the mountains will
generally be in the 25-40 percent range. High temperatures will be 7-
9 degrees above normal through Friday, around normal over the
weekend, warming back up to 3-5 degrees above normal early next
week.

&&

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

&&

$$

Zell

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