438
FXUS65 KPSR 042318
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
418 PM MST Thu Dec 4 2025

.UPDATE...Updated 00z Aviation Discussion...

&&

.KEY MESSAGES...

- Dry and generally quiet conditions will continue through next week
with temperature warming from near normal to above normal levels.

- Sub-freezing temperatures expected for higher terrain areas
including southern Gila County tomorrow morning.

&&

.SHORT TERM /TODAY THROUGH FRIDAY/...
We saw a cool start to the day as the area saw some of the coldest
temperatures this season. Morning lows across the higher terrain
registered in the low 30s while lower desert locales ranged anywhere
from the upper 30s to mid/upper 40s. This is thanks to the
cooler, drier air that has been brought in with the passage of
yesterday`s trough, which is seen quickly exiting to the east
today. While the shortwave trough has now exited well to the east
of the region, the Southwest remains under the influence of
longwave troughing that will help to keep cooler temperatures in
place.

Temperatures for the end of the workweek will remain near to
slightly below normal as lower desert highs top out in the mid to
upper 60s today and tomorrow and upper 50s to low 60s across the
higher terrain. Chilly morning temperatures will continue Friday
morning as lows once again dip near to below freezing across
portions of southern Gila County. Given this, a Freeze Warning is
once again in effect for these areas Friday morning. Across the
lower deserts, morning lows will range between the upper 30s to
low 40s, while a few sheltered locations may dip into the lower
30s.

&&

.LONG TERM /SATURDAY THROUGH MIDDLE OF NEXT WEEK/...
This weekend the aforementioned ridge over the Pacific Ocean will
move eastward, but eventually stall just off the west coast. This
high pressure system will hangout just off the coast and strengthen
through the middle of next week. While the ridge won`t be centered
over the Desert Southwest, we will be under the influence of the
eastern part of the high pressure. This will result in warming
temperatures and continued dry and tranquil weather conditions,
through at least the middle of next week.

H5 heights over the Desert Southwest look to rise into a 576-581 dm
range this weekend and peak around 582-585 dm sometime around the
middle of next week. This will result in temperatures going above
normal during the weekend and rising to around 8-10 degrees above
normal by the middle of next week. Afternoon high temperatures this
weekend will range from the mid 60s to low 70s across the lower
deserts and range from the low to mid 60s across the higher terrain.
High temperatures will then continue to warm through the first half
of next week rising to the mid to upper 70s across the lower deserts
and will be in the upper 60s to low 70s across the higher terrain by
the middle of next week. Morning low temperatures will also be 3-6
degrees above normal by the middle of next week (lower deserts:
upper 40s to low 50s, higher terrain: upper 30s to mid 40s).

&&

.AVIATION...Updated at 2315Z.

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

No aviation weather concerns under some passing high cirrus cloud
decks can be expected throughout the TAF period. The overall wind
pattern will continue to exhibit light diurnal tendencies along
with extended periods of light variability to calm conditions.

&&

.FIRE WEATHER...
Dry conditions will continue to prevail across the region through
next week. Temperatures will be near to slightly below normal today
and tomorrow, warming above normal this weekend, and then going 8-10
degrees above normal by the middle of next week. Winds will be light
and tend to follow their typical diurnal tendencies. Humidities over
the next week will stay elevated with MinRHs mostly ranging between
20-35% much of the time, with good to very good overnight recoveries.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Freeze Warning from 2 AM to 9 AM MST Friday for AZZ556-560-562.

CA...None.
&&

$$

SHORT TERM...Smith
LONG TERM...Berislavich
AVIATION...Lojero
FIRE WEATHER...Berislavich