270
FXUS65 KPSR 051716
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1015 AM MST Fri Dec 5 2025

.UPDATE...
Updated Aviation

&&

.KEY MESSAGES...

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

&&

.SHORT TERM /TODAY THROUGH SATURDAY/...
Our region remains under the influence of a longwave trough, which
can be seen on water vapor satellite imagery. This longwave trough
will continue to promote cooler temperatures across the region.
There is a wide range of temperatures out there early this morning,
with lower desert locations any where from the mid 40s to low 50s,
with higher terrain areas in the mid to upper 30s. These
temperatures are similar to a few degrees cooler than they were at
this time yesterday. Temperatures will continue to cool through the
morning and are forecasted to bottom out at temperatures similar to
yesterday morning (urban lower deserts: mid to upper 40s, rural
lower deserts: upper 30s to low 40s, and higher terrain: upper 20s
to mid 30s). With temperatures similar to yesterday a Freeze Warning
remains in place across portions of southern Gila County. Afternoon
high temperatures today will also be similar to yesterday, with
highs in the mid 60s to upper 60s across the lower deserts and in
the upper 50s to low 60s across the higher terrain.

On Saturday, a high pressure system over the eastern Pacific will
move southeastward, but remain well off the coast of southern
California. With this high pressure system moving eastward, that
will in turn push the longwave trough eastward. So, H5 heights will
rise from 573-576 dm today to 576-579 dm tomorrow. This will result
in temperatures being a few degrees warmer. Afternoon high
temperatures will be right around normal across south-central
Arizona (upper 60s lower deserts and low to mid 60s higher terrain)
and be a few degrees above normal across southwestern Arizona and
southeastern California (upper 60s to low 70s). Morning lows will
also be a few degrees warmer tomorrow, but remain in the 40s to
upper 30s across the lower deserts and in the low to mid 30s across
the higher terrain. With high pressure moving in, dry and tranquil
weather conditions will persist.

&&

.LONG TERM /SUNDAY THROUGH THE END OF NEXT WEEK/...
By Sunday the aforementioned high pressure system in the eastern
Pacific will have moved further south and east and will stall just
off the California coast. With the high pressure pushing further
east the longwave troughing, that had been keeping our region
cooler, will also move eastward and will finally exit our region.
Despite the center of the high pressure system remaining off shore
through the middle of next week, much of Western CONUS will be under
the influence of its eastern flank. H5 heights will rise to around
580-583 dm on Sunday and then rise to 582-585 dm by the middle of
next week. This will result in a gradual warming trend. However,
through early next week multiple shortwaves will be moving from the
Pacific NW/southern British Columbia down into the Plains that will
temporally dampen the ridge, but, the ridge will quickly rebound. If
any of these shortwaves are able to push into the Desert Southwest
at all, it would briefly stall our warming trend for a day.
Nevertheless, afternoon high temperatures, region wide, will go back
above normal on Sunday and warm to around 8-10 degrees above normal
by the middle of next week. Afternoon high temperatures are
forecasted to go from the low 70s (mid to upper 60s) across the
lower deserts (higher terrain) on Sunday to the mid to upper 70s
(upper 60s to low 70s) by the middle of the week.

By the end of next week and heading into next weekend, the ridge
will finally push onshore with the center of the ridge eventually
moving over the Desert Southwest. The ridge will be weakening as it
move onshore, however, with it moving directly overhead temperatures
will continue to gradually warm through at least the end of next
week. H5 heights will rise into the 583-586 dm range by the end of
next week. This will result in afternoon high temperatures 10-12
degrees above normal and morning low temperatures 6-8 degrees above
normal. For the end of next week, afternoon high temperatures are
forecasted to be in the upper 70s to near 80 degrees across the
lower deserts and in the low to mid 70s across the higher terrain.
Morning lows are forecasted to be in the 50s across the lower
deserts and in the 40s across the higher terrain. Additionally with
the a ridge dominating the region, dry and tranquil conditions will
continue through next week and into next weekend.

&&

.AVIATION...Updated at 1715Z.

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

No weather issues will exist through Saturday afternoon under mostly
clear skies. Trends in wind directions and speeds will be nearly
identical to the past 24 hours with extended periods of nearly calm
conditions.

&&

.FIRE WEATHER...
Dry conditions will continue to prevail across the region through
next week. Temperatures will be near to slightly below normal,
warming above normal during the weekend, and then going 10-12
degrees above normal by the end 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...None.
CA...None.

&&

$$

SHORT TERM...Berislavich
LONG TERM...Berislavich
AVIATION...18
FIRE WEATHER...Berislavich