944
FXUS65 KTWC 212217
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
317 PM 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...Main forecast focus today is on warming temperatures
through the middle of next week along with uncertainty regarding a
couple of potential weather systems next week.

Not a cloud in the sky across southeast Arizona this afternoon as a
ridge of high pressure begins to build over the Pacific Coast. Highs
today expected to top out in the mid to upper 70s to low 80s. Winds
are very light today. Tomorrow breezy winds will pick back up again,
especially east of Tucson where sustained winds of 15-20 mph and
gusts up to 30 mph can be expected.

As the ridge of high pressure continues to build over the Pacific
Coast temperatures will continue to warm through the weekend. As the
ridge axis moves east into southeast Arizona by Monday into Tuesday
thickness values will increase higher than normal supporting record
to near record high temperatures Monday through Wednesday
afternoons. Temperatures will be 15-20 degrees above normal during
this period with Tucson with Tucson well on track for the first 90
degree day of the year. Tuesday there is even a 80 percent chance
that Tucson will break a long standing record high of 94 degrees set
back in 1986. These warmer temperatures may catch some by surprise,
so be sure to drink plenty of water and limit time outdoors during
peak heat hours. Minor HeatRisk will be in place over the majority
of southeast Arizona through next week. This level of heat affects
primarily those individuals extremely sensitive to heat, especially
when outdoors without effective cooling and/or adequate hydration.

An upper level feature will be tracking across Baja California to
Sonora Mexico where it will bring instability and moisture into
Southeast Arizona Wednesday into Thursday. However, there is still
uncertainty regarding the trajectory of the system due to the
upstream influences of a trough forming over the Pacific Ocean. The
moisture combined with the increase in instability will bring a very
low (10 percent) chance for dry thunderstorms across the eastern
part of Southeast Arizona on Wednesday and Thursday afternoons,
especially in the White and Chiricahua Mountains. At the very least,
the moisture will allow for some cloud buildups over terrain.

Lastly, the Pacific Ocean trough mentioned before will be moving
inland behind the weaker upper feature to bring some breezy
conditions to all of southeast Arizona next Friday. It is still
early and the ensemble models are still not on the same page on
exactly how the 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 23/00Z.
SKC conditions throughout the period. Surface winds WLY/NWLY at less
than 10 knots becoming variable after 22/02Z. SWLY/WLY winds pick up
tomorrow after 22/18Z with speeds of 9-13 kts and gusts to around 20
kts. Aviation discussion not updated for TAF Amendments.

&&

.FIRE WEATHER...Warm and dry conditions will remain over the next
few days with further warming expected early next week. This will
result in afternoon temperatures across Southeast Arizona 15 to 20
degrees above climatological normal. With considerable dry and hot
conditions, humidities will remain at critical levels throughout the
next 7 days. Although winds over the next several days will be
mostly light and diurnal, elevated west to southwest winds will
occur Saturday, with speeds of around 15-20 mph and gusts to around
25-30 mph.

A feature worth watching will be the weak upper low currently
expected to move across the Baja CA and Sonora, Mexico sometime late
next week, which could bring just enough moisture and instability to
portions of southeastern AZ to cause isolated dry thunderstorms.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...

None.

&&

$$

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