176
FXUS65 KPSR 082010
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
110 PM MST Sat Nov 8 2025

.KEY MESSAGES...

- Unseasonably warm weather will prevail through at least the middle
of next week with some local daily high temperature records possible
Sunday and Monday.

- A cooler and wetter weather pattern may arrive into the Desert
Southwest by the end of next week.

&&

.SHORT TERM /Today through Monday/...
The first vestiges of a pronounced pattern amplification phase over
the Conus was evident in afternoon WV imagery with deepening
troughing over eastern North America and a growing meridional jet
component in the northeast Pacific. In response, modeling remains in
excellent agreement depicting very anomalous ridging materializing
over the SW Conus in the next 36 hours with H5 heights building near
590 dm, or very near a climatological extreme by mid-November
standards. Not surprisingly given this pattern, clear skies and dry
weather are assured with temperatures 5F-10F above the daily
normals. In fact, NBM output still suggests nearly a 75% chance of
KPHX reaching a record high Sunday afternoon. While H5 heights begin
to retreat Monday in response to wave breaking over the ridge axis,
tropospheric thermal profiles will be slower to respond such that
temperatures Monday should only be marginally "cooler" than a
persistence forecast.

&&

.LONG TERM /Tuesday through Saturday/...
Confidence remains high that upper-lvl ridging will prevail over the
Desert Southwest through at least the middle of next week as a
trough of low pressure takes aim on coastal California and the
Pacific Northwest. Under the presence of ridging aloft, daily highs
across the lower deserts will continue to top out around 5 to 8
degrees above normal Tuesday through Thursday. Starting on Wednesday
we will also see an increasing fetch of high clouds progressing into
our forecast area ahead of the approaching trough.

Deterministic models and ensemble members are now coming into better
agreement showing the onshore progression of the upper trough and
displacement of the upper ridge ewd into the Southern Plains late
next week. As this occurs, a large plume of Pacific moisture will
begin to overspread CA and the Intermountain West from Thursday into
Friday. This system will likely bring widespread measurable
precipitation to coastal and interior California. The combination of
increasing mid-lvl southwesterly flow will transport moisture into
the Desert Southwest by Friday into Saturday and that is when we
will see rain chances increase from W to E across our forecast area.
There are still subtle differences in timing in model QPF fields,
however most members are now showing measurable rainfall in south-
central AZ. Coincidentally, NBM PoPs have now increased up to 20-40%
across much of the region late Friday into Saturday. Due to the
arrival of negative height anomalies associated with the trough, sfc
temperatures are expected to cool into the lower 80s by Friday and
potentially mid to upper 70s on Saturday.

&&

.AVIATION...Updated at 1700Z.

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

No major weather issues will exist across the region through Sunday
afternoon under clear skies. Winds patterns today will be nearly
identical to Friday with extended periods of calm conditions. Some
local gusts around 15kt will be possible late Sunday morning across
PHX area terminals, but should have little affect on operations.


&&

.FIRE WEATHER...
Warm and dry conditions with well above normal temperatures
will prevail this weekend and through much of next week.
Afternoon minimum humidity will bottom out between 15-20% over
the next several days with overnight recoveries ranging from
30-60%. Winds will remain light, generally 15 mph or less with
occasional afternoon gusts and will tend to follow a typical
diurnal upslope/nocturnal drainage pattern.

&&

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

&&

$$

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