712
FXUS65 KPSR 222057
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
155 PM MST Thu Oct 22 2026

.KEY MESSAGES...

- Thunderstorms capable of severe weather and flooding will exit
through eastern Arizona this evening with drier air surging into the
region.

- More benign weather conditions will filter into the area
Friday and through the weekend with only a few lingering showers
over mountain locations in Arizona.

- Below normal temperatures through early next week will warm closer
to the seasonal average by the middle of next week.

&&

.SHORT TERM /Today through Saturday/...
Deep negative height anomalies were finally moving inland across
southern California with a notable trough axis rotating into SE
California/SW Arizona. A strong jet core has shifted to the
eastern side of the larger circulation ensuring further lifting of
cold core aloft towards southern Utah while allowing deep downstream
meridional flow to veer more W/SW. While much of the eastern CWA
remains in the right rear jet quadrant favorable for synoptic
ascent this afternoon, the propagation of the aforementioned trough
axis will place the region under growing subsidence after this
evening. Concurrently, a plume of ample moisture remains situated
from the Phoenix metro eastward with PWATS around 1.25" and low
level mixing ratios 10-12 g/kg yielding MLCape 1000-1500 J/kg.
Kinematic fields continue to support organized supercell structure
given 0-6km shear above 50kt while hodographs increasingly becoming
straight-lined would point towards splitting cells, and similar to
yesterday preferring left movers producing very large hail
(sufficient 400-600 J/kg CAPE within the -10C to -30C hail growth
region as well). While a tornado threat will persist in Gila County
with a Watch through 8 pm, weakening 0-1km shear vectors and higher
LCL`s may keep the greater threat to the east and north of Gila
County.

Recent objective analysis depicts the wedge of dry air behind a
theta-e boundary and in association with the deeper veered winds
already bisecting the Phoenix metro early this afternoon. This
boundary will continue to progress eastward through the evening
eroding instability and eliminating the convective threat beyond
mid evening. It`s not out of the question a lingering shower could
affect eastern Arizona high terrain tonight, however HREF and REFS
output offer only minimal support for this outcome. On Friday, a
secondary vorticity center emanating over the East Pacific will dive
into the mean trough position across the SW Conus creating a quasi-
cutoff low that will persist through Saturday. With better moisture
already scoured from the area, only mountain location may be capable
of squeezing out a few diurnal showers under the cold core Saturday
with lower elevations remaining dry. This system will ensure H5
heights remain sequestered under 572dm through Saturday with
excellent forecast confidence of temperatures solidly 10F below
normal.

&&

.LONG TERM /Sunday through Thursday/...
Model guidance suggests the aforementioned cutoff should remain over
the region through the entire weekend, but continuing to weaken
allowing the airmass to slowly warm over time. NBM forecast highs
Sunday show readings rebounding into the lower 80s over the western
lower deserts to near 80 degrees in the Phoenix area. By Monday, the
trough is likely to finally push east of the region with modest
upper level ridging prevailing over the Desert Southwest. The
increased heights and continued dry conditions should push daytime
highs back into the normal range (mid 80s) going into the middle of
next week.

&&

.AVIATION...Updated at 1803Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
The main aviation concern through through early this afternoon will
lower CIGs around 5-6 kft. These lower CIGs will gradually lift and
scatter out through the afternoon and evening with skies becoming
clear overnight. VCSH remain only in the KSDL TAF through 19Z as
showers remain to the NE of the terminal. Otherwise dry conditions
are expected as the shower and storm threat for today has shifted to
the higher terrain to the east of the Phoenix Metro. Winds will
predominately exhibit a westerly component through the evening with
some occasional gusts up around 20 kt expected from the late
afternoon through the early evening. Winds will then go back SE`rly
overnight.


Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation weather concerns are anticipated through the
forecast period. Winds will favor a southwesterly to westerly
component at KBLH and westerly at KIPL. Gusts up to 25 kts will
become common at both terminals through mid (KBLH) to late (KIPL)
this evening. FEW to SCT clouds, mostly aoa 7 kft, will continue
into the evening before becoming mostly clear overnight.

&&

.FIRE WEATHER...
Strong to severe thunderstorms with heavy rainfall will remain
possible over eastern districts through this afternoon before rapid
drying spreads through the area this evening and tonight. The
heaviest rainfall will be focused more across higher terrain areas
north and east of Phoenix. MinRHs today will again be in a 30-60%
range before dropping more into a 25-40% range for Friday and
Saturday as cooler air settles into the region. Gusty west winds
upwards of 25-30 mph will be possible across the western districts
through this evening with winds becoming light starting tonight.
Overall quiet weather conditions are forecast for this weekend into
next week with fairly stable humidities and temperatures rebounding
back into the normal range early next week.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Flood Watch until 11 PM MST this evening for AZZ545-547-552-
     556>558-560>563.

     Flood Watch until 5 PM MST this afternoon for AZZ541-549-555.

CA...None.

&&

$$

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

NWS Phoenix (PSR) Office