694
FXUS65 KPSR 011744
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1044 AM MST Mon Dec 1 2025

.UPDATE...Updated Aviation Discussion.

&&

.KEY MESSAGES...

- Overall dry and fairly quiet weather conditions are expected
  throughout the coming week. Temperatures will gradually drop to
  slightly below normal by late week before warming again into
  next week.

- A passing weak weather system today will bring breezy conditions
  across the Lower CO River Valley, while a second system late
  Wednesday and Thursday may bring light precipitation chances to
  the Arizona high terrain.

&&

.SHORT TERM /TODAY THROUGH TUESDAY/...
A weak shortwave trough is currently tracking southeastward
through the Four Corners area with a band of high clouds moving
through central Arizona. This system will not bring much in the
way of changes to our area today, but it will result in some
breezy winds across the Lower CO River Valley and drop
temperatures a couple of degrees from yesterday. After the
disturbance quickly moves to our east by tonight, we will remain
under broad cyclonic northwesterly flow on Tuesday with
temperatures falling another 1-2 degrees pushing highs into the
normal range. Dry conditions, mostly clear skies, and light winds
are also expected on Tuesday.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Models continue to trend away from any impactful weather later
this week with a second Pacific trough now expected to take a more
northerly track. Ensembles are now in very good agreement the
next system for later Wednesday and Thursday will be much like the
first progressive system. Even compared to model runs yesterday,
the system shows a more eastward and northerly track shift
bringing the bulk of the energy across northeastern Arizona.
Additionally, the fact the trajectory of the trough is completely
inland and it is now likely to take a shallower track through our
region moisture will be even more limited than previously
expected. As are result, NBM PoPs have dropped dramatically since
yesterday with PoPs dropping to below 10% for all of the western
deserts and even the western half of the Phoenix metro. Depending
on the exact track of the system, the Arizona high terrain may
still see some light shower activity, but expected QPF amounts
have fallen below 0.05".

Temperatures should also dip a bit further with the passage of
the trough with lower desert highs falling more into the mid to
upper 60s for Thursday and Friday. Guidance also heavily favors a
more expansive ridge setting up over the eastern Pacific later
this week with a fairly likely chance of a portion of the ridge
will edge into our region by the weekend. Although the ridge is
shown to flatten out over the weekend, the weather pattern may
support the ridge to rebuild again and push farther into our
region during the first half of next week. We have high forecast
confidence in dry conditions prevailing well into next week with
temperatures eventually warming to above normal.

&&

.AVIATION...Updated at 1744Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT; and
Southeast California/Southwest Arizona including KIPL and KBLH:

No major aviation weather concerns are anticipated through the TAF
period. Outside of breezy northerly winds at KBLH gusting upwards
of 20-30 kts at times through the rest of this morning, winds at
the terminals will overall remain light, aob 7 kts, through the
TAF period. Extended periods of variable winds will be common
across the Phoenix area with a light N-NW component expected to
develop by late afternoon/early evening before switching back to
the east tonight. A brief light westerly component may try to
develop overnight tonight (~08Z-12Z) at KPHX, however, have not
added this to the TAF given the low confidence. Otherwise, mostly
clear skies will prevail outside of FEW passing high clouds.

&&

.FIRE WEATHER...
Dry conditions will continue to prevail for the bulk of the region
this week as two mostly dry weather systems pass near or through
portions of the region. Today`s weak weather system will only
bring breezy northerly winds across the Lower CO River Valley and
slightly cooler temperatures. Another weather system for late
Wednesday and Thursday may bring light precipitation chances, but
mostly to higher terrain areas. Humidities this week will stay
elevated with MinRHs mostly ranging between 25-35% much of the
time, with good to very good overnight recoveries. Winds are
expected to stay light across the eastern districts, while another
round of breezy conditions will be possible across the western
districts Wednesday and Thursday.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&

$$

SHORT TERM...Kuhlman
LONG TERM...Kuhlman
AVIATION...Smith
FIRE WEATHER...Kuhlman