681
FXUS65 KTWC 232107
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
207 PM MST Mon Jun 23 2025

.SYNOPSIS... Below normal temperatures again today will then give
way to a gradual warming trend to above normal through the work
week. Moisture will creep into southeastern Arizona and bring
chances for showers and thunderstorms this week, especially
Tuesday onwards. Chances will be highest near the New Mexico
border with just a slight chance closer to Tucson.

&&

.DISCUSSION... Enough moisture has moved into the area leading to
the development of clouds mainly east of Tucson. Some virga
developed early this afternoon over the Chiricahuas but quickly
dissipated. The trough to our west continues to push further
southwest and is now centered in central California. The broad
ridge to our east over the Mid-Atlantic persists, continuing the
trend of dry southwesterly flow over southern Arizona. GOES water
vapor and precipitable water products show a gradient of
atmospheric moisture over southeastern Arizona with satellite
measured precipitable water values exceeding one inch in far
southeastern Cochise county with a swath of this richer moisture
making its way into southern New Mexico.

As this west coast trough continues on its journey toward the
southwest US, the low to mid level flow will shift to be more
southerly bringing in a better supply of deep moisture into
eastern Arizona. By tomorrow, precipitable water will be greater
than 1 inch Tucson eastward. Shower and thunderstorm chances
Tuesday afternoon and evening are highest in Cochise county (25-50
percent) and 15-30 percent chances into eastern Pima, Santa Cruz,
Graham, and Greenlee counties. The model trend noted early this
morning continues to indicate the potential for shower activity
earlier in the day as far west as Tucson.

By Wednesday afternoon the west coast trough will lift out of the
region followed by a weak shortwave trough that looks to enter
our area by Thursday afternoon. As the original trough moves on,
the likelihood for precipitation dwindles to the far eastern edge
of Cochise county as the wind direction shifts to be more
westerly. When the shortwave trough arrives on Thursday, moisture
may return as far west as Tucson increasing the chance for showers
to develop. There is a level of uncertainty how much moisture
will push westward on Thursday and will depend on how well
moisture is introduced to the are from thunderstorm outflows and
the synoptic pattern.

By this weekend the broad upper high over the Mid-Atlantic will
have begun shifting westward, bringing highs from near normal
early this week to above normal again by the end of the week.
Lingering moisture may produce a slight chance of a shower or
thunderstorm this weekend but otherwise chances should fall off.
The trend continues for the center of the westward migrating high
into the Four Corners region by early to mid next week. This
transition would allow for richer monsoon moisture to arrive in
southeastern Arizona by the middle of next week.

&&

.AVIATION...Valid through 25/00Z.
FEW to SCT clouds east of Tucson AOA 10 to 15k ft AGL will
persist through 24/06Z when clouds push further west over KTUS
then persist throughout the forecast period. SFC winds will be
from the southwest AOA 5 to 10 kts until 24/05Z gradually weakening
to variable winds overnight. By 24/18Z winds will pick up to be
from the west-southwest at 5 to 10 kts until the end of the
forecast period. Slight chance (15 to 20 percent) chance for
showers to develop mainly east of KDUG from 23/22Z through
24/05Z. A chance for showers (30 to 50 percent) tomorrow
afternoon mainly west of KOLS and a 15 to 30 percent chance for
showers KTUS. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER... Below normal temperatures again today with highs
gradually rising through the week. Minimum relative humidity
values generally 10-20 percent across southeastern Arizona today,
with higher values closer to the International Border and in
mountainous locations. Southwesterly winds today generally 10-15
mph with afternoon gusts to 25 mph. Moisture will begin to move in
from the east this week. This moisture will raise minimum RH will
be closer to 30 percent in Cochise county decreasing as you move
northwestward toward Tucson; with Tucson having minimum RH around
10 percent. This will produce a slight chance of showers and
thunderstorms in southeastern Cochise county today and expanding
chances through Cochise, Graham, Greenlee, Santa Cruz, and eastern
Pima counties on Tuesday...with lower chances towards the west.
Chances decrease on Wednesday, then return on Thursday.

&&

&&

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

$$

Malarkey

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