306
FXUS65 KPSR 252115
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
215 PM MST Tue Nov 25 2025

.KEY MESSAGES...

- Dry and tranquil weather conditions are expected through the
  rest of this week with temperatures gradually warming from near
  normal to slightly above normal by the end of the week.

- Another weather system may bring much cooler temperatures and a
  slight chance of precipitation, mainly to the AZ high terrain,
  Sunday into early next week.

&&

.SHORT TERM /TODAY THROUGH THURSDAY/...
Latest mid-lvl wv imagery and 500 mb streamline analysis reveals a
broad trough of low pressure encompassing much of the Lower 48 while
a high amplitude ridge of high pressure continues to build off the
coast of California. Our forecast area is on the eastern periphery
of the strengthening ridge under dry northwesterly flow aloft. This
pattern has brought tranquil weather conditions to the Desert
Southwest under clear skies and light winds this afternoon.
Temperatures are expected to top out right around normal for late
November in the upper 60s to lower 70s across the lower deserts
and low to mid 60s over the high terrain areas. Heading into
tonight the boundary layer will continue to dry out as dew points
fall into the 40s. Therefore, any fog that develops Wednesday
morning will be very localized, mainly relegated to the lowest
elevations of the Imperial Valley and Gila River Valley. Low
temperatures across the region Wednesday morning will mainly range
from the low 40s to low 50s.

As the ridge of high pressure to our west migrates over the Desert
Southwest, heights aloft will gradually rise, maxing out around
584-586 dam Wednesday and Thursday. 500 mb hghts of this magnitude
are around the 90th percentile of climatology for this time of
year. These increasing heights and mid-level temperatures will
result in surface highs rising to the mid to upper 70s across the
lower deserts and in the mid 60s to low 70s across the higher
terrain. Morning lows will remain mild in the mid 40s to low 50s,
with the warmest lows in the mid 50s confined to more urban areas.
The only sensible change in weather conditions through the middle
of this week will be increasing high level cloud cover, especially
on Thursday. Otherwise, expect dry weather to prevail.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
On Friday a weak shortwave trough will move through the region.
This will result in lowering heights aloft, with 500 mb heights
will lower to around 575-577 dm. This will result in temperatures
cooling a degree or two, but will remain above normal. Afternoon
high temperatures will be in the mid 70s across the lower deserts
and in the upper 60s to low 70s across the higher terrain. Dry
conditions will persist on Friday.

By this weekend and into early next week, global ensemble members
all show a deep trough traversing the region. They still differ a
little on the exact timing, but tend to favor sometime in the Sunday-
Tuesday window. They are in good agreement that this trough will be
taking an inland trajectory down from the Pacific NW and not move
down along the eastern Pacific Ocean and then move inland like the
last low pressure system did. With this trough taking an inland
trajectory the system won`t be bringing a lot of moisture to the
region. PWATs currently look to only rise to a 0.5-0.7" range (the
ECMWF has PWATs in a 0.5-0.7" range, the GEFS has PWATs staying
below 0.6", and the Canadian Ensemble has PWATs only in a 0.3-0.4"
range). This increase in moisture (in combination with forcing from
the trough and terrain itself) would likely support showers across
the higher elevations to the north and east of the Phoenix Metro.
Showers across the lower deserts will likely be harder to come by,
with this amount of moisture, and would need more help than that of
the higher terrain areas. Nevertheless, another weather system will
be moving through the region by early next week and would support
showers across at least some portions of the CWA along with cooling
temperatures. With this weather system temperatures look to cool
back off below normal. Stay tuned for future updates.

&&

.AVIATION...Updated at 1715Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No aviation concerns this forecast period with mostly clear skies
and light diurnal wind shifts.

Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation concerns this forecast period with clear skies and
light west/northwest winds.

&&

.FIRE WEATHER...
Dry and tranquil weather conditions will continue through the
remainder of this week with temperatures rising to around 3 to 6
degrees above average. This warmer and drier pattern will result in
MinRHs lowering to around 25-35% through the end of this week while
overnight recoveries remain generally fair to good. Winds will be
less than 10 mph and follow their normal diurnal tendencies with
only marginal upslope gusts into the upper teens to low 20s. By this
weekend and into early next week another weather system will move
through the region cooling temperatures back off below normal and
bringing another chance for showers and wetting rains to the the
higher terrain of southcentral AZ.

&&

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

$$

SHORT TERM...Salerno
LONG TERM...Berislavich
AVIATION...Frieders
FIRE WEATHER...Salerno