417
FXUS65 KPSR 031139
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
439 AM MST Wed Dec 3 2025

.UPDATE...Updated 12Z Aviation Discussion.

&&

.KEY MESSAGES...

- Dry and generally quiet conditions are expected to continue into
  next week.

- Transient low pressure will help generate some afternoon breeziness
  for the Lower CO River Valley Wednesday and early Thursday.

- Near to slightly below normal temperatures continue through the
  end of the workweek before going above normal this weekend, and
  then gradually warming through the middle of next week.

&&

.SHORT TERM /TODAY THROUGH FRIDAY/...
Upper level water vapor satellite imagery and objective analysis
early this morning reveal broad high pressure over the eastern
Pacific, quasi-zonal flow over Arizona, and a positively tilted
trough digging into southern NV and SE CA. This trough will be
moving through our area today and into Thursday, but will quickly
move into the Plains by Thursday evening. This trough will be
bringing a dry cold front through our region which will cool
temperatures down and bring breezy conditions to portions of the
CWA. Since this trough is taking an inland trajectory it will not be
brining much moisture into our region. The SPC mesoanalysis shows
PWATs are currently in a 0.3-0.4" range across our area and forecast
models only show PWATs rising to around 0.5", associated with the
cold front. Therefore most, of not all, of the CWA will remain dry.
The slight increase in moisture will just result in some mid and
high level clouds associated with the passage of the cold front
today. Any precipitation with this system is expected to remain
confined to the Rim and White Mountains. There is a slight chance
(less than 20%) that far eastern Gila County could see some isolated
light showers or sprinkles this afternoon. Additionally some
snowflakes are possible for the highest elevations.

As previously mentioned this system will also bring some breezy
conditions to portions of the CWA. These breezy conditions are
expected across SE CA and the Lower CO River Valley today into
Thursday morning. The highest wind gusts are expected this afternoon
and early evening with gusts upwards of 25-30 mph. Elevated winds,
20-25 mph, are expected to continue into the overnight hours and
through Thursday morning before tapering off heading into
Thursday afternoon.

Additionally, this system and associated cold front will bring in
cooler air. This will cool temperatures off to near to slightly
below normal for the remainder of the workweek. Afternoon high
temperatures will range from the mid 60s to around 70 degrees, with
high elevations seeing temperatures ranging from the mid 50s to low
60s. Morning lows will also be on the cooler side with lower desert
areas in more urban areas seeing morning lows in the lower 40s, but
more rural lower desert locations seeing morning lows dip into the
mid to upper 30s. Higher elevations will see morning lows near
freezing and in the low to mid 30s. Some freeze products may be
needed for some of the higher terrain areas, like western Joshua
Tree National Park or even the Tonto Basin.

&&

.LONG TERM /SATURDAY THROUGH MIDDLE OF NEXT WEEK/...
This weekend, the aforementioned ridge over the Pacific Ocean will
move eastward and stall just off the west coast. WHile the center of
the ridge will remain over the eastern Pacific Ocean, the eastern
portion of the ridge will be over much of Western CONUS. The center
of this ridge will strengthen through at least the middle of next
week. This ridge will dominate the eastern Pacific and Western CONUS
while a longwave trough dominates Central and Eastern CONUS.
Multiple shortwave troughs look like they will slide down the
western part of the longwave trough, moving from the Pacific
NW/southern British Columbia down into the Plains, temporarily
flattening the ridge. H5 heights, over the Desert SW, look to rise
into a 576-581 dm range this weekend and peak around 582-585 dm
during the middle of next week.

With high pressure dominating the region this weekend through at
least the middle of next week dry and tranquil conditions will
continue as well. Temperature wise, they will gradually warm this
weekend and continue to warm through the middle of next week.
Afternoon high temperatures will be near to slightly above normal
this weekend (lower deserts: upper 60s/low 70s, higher terrain: 60s)
and warm to 8-10 degrees above normal (lower deserts: mid to
upper 70s, higher terrain: upper 60s to mid 70s) by the middle of
next week. Morning low temperatures will warm to around 3-6
degrees above normal (lower deserts: upper 40s to low 50s, higher
terrain upper 30s to mid 40s) by the middle of next week.

&&

.AVIATION...Updated at 1140Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No aviation weather concerns under some passing mid to high clouds
can be expected throughout the TAF period. The overall wind
pattern will continue to exhibit typical diurnal tendencies with
speeds generally aob 7 kts along with extended periods of light
variability to calm conditions, especially during diurnal
transitions.

Southeast California/Southwest Arizona including KIPL and KBLH:
Winds at KBLH will be northerly through the whole period, whereas
at KIPL current westerly winds will go northerly this afternoon
and evening and then back westerly during the overnight hours.
Wind speeds at KIPL will generally be aob 10 kt through the
period. At KBLH, current light winds will pick up speed by the
late morning hours with gusts of 20-25 kt this afternoon. Wind
speeds will then drop to aob 10 kt during the evening and
overnight hours. FEW high clouds are expected through the period.

&&

.FIRE WEATHER...
Dry conditions will continue to prevail across the region this
week with a second dry weather system passing mainly to the north
of the region today into Thursday. This system will however bring
another round of breezy conditions (wind gusts 20-30mph) across
SE CA and the Lower CO River Valley this afternoon through
Thursday morning with light winds prevailing across the eastern
districts. Humidities this week will stay elevated with MinRHs
mostly ranging between 20-35% much of the time, with good to very
good overnight recoveries. Near to slightly below normal
temperatures are forecast through Friday before a warming trend
pushes temperatures above normal by early next week.

&&

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

$$

SHORT TERM...Berislavich
LONG TERM...Berislavich
AVIATION...Berislavich/Lojero
FIRE WEATHER...Berislavich/Kuhlman