352
FXUS65 KTWC 210901
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
201 AM MST Fri Mar 21 2025

.SYNOPSIS...Main story over the next 7 days is the increasing
temperatures through the weekend and into next week. Afternoon
temperatures across Southeast Arizona will be 15 to 20 degrees
above climatological normal, with the Tucson Metro Area reaching
record high readings next Tuesday. Those enjoying outdoor
activities over the next week should stay hydrated and take proper
precautions when outside over the next week.

&&

.DISCUSSION...The start of Spring brings Southeast Arizona with
three parts. These parts will bring different impacts and
potentially some uncertainty: heat, a weak feature, and late week
weather system.

The first part will be the heat that is starting to rear itself.
Ensemble models are in a large agreement of a ridge of high
pressure building across the western coast today and then moving
into the intermountain by Sunday. This will boost thickness
levels higher than normal and resulting in warmer than normal
temperatures. A 15-20 degrees above normal across the region.
Tucson is on track to reach 90F degrees early next week with
Tuesday having a shot (50%) at breaking the record of 94 set in
1896; the latest forecast is 95F for Tuesday. These warmer
temperatures will bring Minor Heat Risk this weekend and lasting
through majority of the week. Winds will be generally light
through this period of warming with the exception on Saturday. As
the ridge builds, a minor shortwave will be passing through to
elevate winds Saturday afternoon. Wind speeds will be 15 to 20 mph
with gusts up to 30 mph. The strongest of those speeds will
towards the New Mexico state line.

An upper level feature will be tracking across Baja California to
Sonora Mexico where it will bring instability and moisture into
Southeast Arizona. This second part is slowly coming together with
the all of the ensembles showing this feature. Yet, there is not
agreement on trajectory of the system due to upstream influences
of a trough forming over the Pacific Ocean. The 75th-25th
percentile precipitable water will increase up to 0.3 to 0.49
inches by Wednesday afternoon to Thursday. With the increase
instability, partly due to the strong surface heating in the early
week, it will bring less than 10 percent (but a non-zero chance)
for dry thunderstorm for the eastern part of Southeast Arizona,
especially the White Mountains and Chiricahua Mountains. Low
forecaster confidence, but noteworthy event to keep an eye out.

Lastly, an early peak into the late week and into the weekend
will be a trough. That Pacific Ocean trough mentioned before will
be moving inland to bring some breezy conditions. It is still
early and the ensemble models are not on the same page on how that
trough will progress. Cluster analysis of the three ensemble
model`s members having a timing and amplitude difference. At the
moment, there is a lean for the trough to stay north of Arizona
with a potential scenario (20% of ensemble members) for a little
deeper and moving inland faster. All potential scenarios will
bring breezes, but the latter scenario will have the stronger end
of the breezes and elevating fire weather concerns. Still, it is
a ways away but something to keep in mind by early next week.

&&

.AVIATION...valid through 22/12Z.
Clear skies prevail through the forecast period. This morning
surface winds will be less than 10 knots and variable until
21/18Z. Then winds becoming westerly to northwesterly at 8 to 12
knots with the occasional late afternoon to early evening gusts.
After 22/02Z, winds return to light and variable through the
overnight. Aviation discussion not updated for TAF Amendments.

&&

.FIRE WEATHER...Dry and warm conditions expected for the next 7
days. Afternoon temperatures will be 15 to 20 degrees above
seasonal normals with Tuesday being one of the warmest days. Winds
will be less than 15 mph with the occasional late afternoon gust
for the next several days. Saturday afternoon will be an exception
with westerly to southwesterly winds 15-20 mph and gusts up to 30
mph, especially out east towards the New Mexico state line.

Extended outlook: A feature will be tracking from Baja California
to Sonora Mexico starting on Wednesday through Thursday. This
feature will bring some moisture and instability to produce
isolated dry thunderstorms for Sky Islands and the White
Mountains. Chances are low, less than 10 percent, but it is a
non-zero chance for a lightning strike in the middle of the week.
This feature will be worth watching. Then later in the week and
into the weekend, ensemble models show a weather system that will
bring breezy conditions area wide and elevating fire weather
concerns.

&&

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

$$

Strongman


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