874
FXUS65 KPSR 022311
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
410 PM MST Wed Jul 2 2025

.KEY MESSAGES...

- Chances for isolated to scattered thunderstorms will exist through
this evening across south-central Arizona with the potential for
strong gusty winds, blowing dust, and localized heavy rainfall.

- After lingering chances for a isolated thunderstorms Thursday,
drier conditions will end any rain chances beginning Thursday night.

- Near normal temperatures will be common through Saturday before
a warming trend begins early next week.

&&

.NEAR TERM/THIS AFTERNOON THROUGH EARLY THURSDAY MORNING/...
Current RADAR indicates showers and thunderstorms occurring in Gila
County at this time. The primary forecast concerns in the near term
are scattered thunderstorms across south-central and eastern
Arizona, with associated strong gusty winds, blowing dust, and
localized heavy rainfall. Convection, which is already occurring, is
expected to intensify over higher terrain areas with hi-res CAMs
indicating scattered showers and thunderstorms developing and moving
into the foothills of the east valley and potentially into the
Phoenix metro, by late afternoon/early evening where even a
thunderstorm or 2 could be severe. Strong outflow winds could impact
the Phoenix valley, with DCAPE values of 1200-1400 J/kg promoting
blowing dust and reduced visibility. Thunderstorm activity will
gradually weaken after midnight, with isolated showers lingering
over higher terrain east of Phoenix into early Thursday morning.

&&

.SHORT TERM/TODAY THROUGH THURSDAY/...
The current synoptic set up shows an unseasonably strong Pacific low
centered near Los Angeles and the sub-tropical high slowly
retreating to the northeast into Colorado. Southeasterly flow since
yesterday continues to feed modestly moist air into Arizona to as
far north as southern Nevada with PWATs now up to between 1.0-1.2"
over the southern half of Arizona. This moist fetch is expected to
last into this afternoon with PWATs likely peaking between 1.2-1.4"
and low level mixing ratios mostly between 8-10 g/kg. This amount of
moisture would normally not be sufficient for a good amount of
monsoon storm activity, but with the help of the incoming
(weakening) Pacific low, the moisture should end up being sufficient.

For Thursday, model guidance continues to show the weakening Pacific
trough tracking northeastward through northern Arizona with dry air
surging eastward across the state. For the most part, guidance shows
only 10-15% chances for any additional showers or thunderstorms
across the south-central Arizona lower deserts Thursday morning and
early afternoon to as high as 30-35% over Gila Co. Given the drying,
any activity will likely be on the weaker side with potential
rainfall amounts much less than today. Temperatures for today and
Thursday will be noticeably less hot than the past few days with
highs at or just below normal.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
As the weather pattern settles back into westerly dry flow over the
majority of the region, rain chances are expected to come to an end
by Thursday night. PWATs are forecast to drop down to between 0.8-
1.0" starting Friday and likely last there through the rest of the
4th of July weekend. Near normal temperatures are likely to continue
into Saturday with overnight lows for rural desert areas easily
falling into the 70s as moisture decreases, but lows within Phoenix
area still likely to stay just above 80 degrees.

Model uncertainty increases considerably next week as the GEFS shows
an increase in moisture by around Tuesday, whereas the EPS keeps the
moisture well to the south. Both generally agree the sub-tropical
ridge will again set up over our region by early next week, first
centered just to our east before gradually shifting westward through
our region during the middle of next week. Heights are also favored
to rise during this time as the ridge strengthens, pushing H5
heights from 590-592dm starting Sunday to as high as 595-597dm by
the middle of next week. The recent shift for a stronger ridge
setting up over our region has abruptly turned conditions noticeably
hotter for next week with NBM highs now mostly between 110-113
degrees by Tuesday. If this new scenario of a stronger ridge comes
to fruition and moisture stays out of our area, expect forecast
temperatures to trend even hotter than the latest forecast. If the
GEFS is more correct showing better moisture, than we may see at
least a return of monsoon activity for higher terrain areas.
However, for now it does not look very promising for any decent
monsoon storms through at least the first half of next week.

&&

.AVIATION...Updated at 2310Z.

South Central Arizona including KPHX, KIWA, KSDL, KDVT:
Gusty outflow winds with around a 30% chance for evening BLDU and
TSRA directly impacting the terminals will be the primary weather
hazard, though confidence is fairly low with respect to the exact
timing and details of these impacts. Confidence is fairly good
(better than 50%) that TS already formed over mountains to the NE,
as well as across SE Arizona will send multiple outflow boundaries
into the PHX airspace by early evening. Outflow arrival may occur as
early as 00-01Z, but may also be delayed closer to 02Z with an E/SE
component initially favored. This direction would favor at least
lofted dust being pulled into the metro with MVFR (or lower)
visibility most likely at KIWA, with slightly lower chances at
KPHX.

Assuming additional TS form behind outflow around the Phoenix metro
during the early evening, multiple outflow boundaries with very
gusty winds will be common though exact wind directions will
largely be dictated by the originating location of the thunderstorm
downdraft. At this time, a S/SW return outflow boundary would be
more preferred from cells originating near the Estrellas. Any direct
TS over a terminal may yield very erratic wind directions, and have
maintained a Prob30 during the most likely time frame. Even within
TS, cigs should remain above 8K ft AGL with cloud decks above 10K
for most of the time frame. Eventually, overnight winds should turn
easterly through Thursday morning before returning to a W/SW
component into the afternoon with building cloud decks over higher
terrain.


Southeast California/Southwest Arizona including KIPL and KBLH:
No major weather issues will exist through Thursday afternoon under
a few, occasional midlevel cloud decks. Wind directions will
generally vary between SE during the morning/early afternoon and SW
during the evening/overnight period. A few late afternoon/early
evening gusts around 20kt will be common, especially at KBLH.

&&

.FIRE WEATHER...
Increased moisture along with an incoming weather system is expected
to bring an active day today across the eastern districts. Shower
and thunderstorm chances today across the eastern districts are
between 30-50% with gusty erratic winds likely to occur with the
thunderstorm activity. Humidities will continue to improve today
with MinRHs of 20-30% for the eastern districts to 15-20% for the
western districts. A drying trend will begin Thursday with much more
isolated chances for showers and thunderstorms for the eastern
districts. MinRHs Thursday will mainly dip to between 15-20%. Even
drier air will filter into the region by the weekend with MinRHs
falling to 10-15% by Sunday. Temperatures will run near normal
through Saturday before heating up again into next week.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Blowing Dust Advisory until 7 PM MST this evening for AZZ553-554.

CA...None.

&&

$$

SHORT TERM/LONG TERM...Kuhlman/95
AVIATION...18
FIRE WEATHER...Kuhlman