059
FXUS65 KPSR 122331
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
431 PM MST Tue May 12 2026

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

&&

.KEY MESSAGES...

- Temperatures will cool a few more degrees the rest of the week,
  however remain in a slightly above normal range.

- Breezy conditions will develop along the Lower Colorado River
  valley and Arizona high terrain on Wednesday, then return to the
  area over the weekend.

&&

.SHORT TERM /Today through Thursday/...
Early afternoon objective analysis depicts a 590dm H5 anti-cyclone
centered over western New Mexico slowly being dislodged and de-
amplified by the combined effort of subtropical energy lifting north
from the Baja into the SW Conus and stronger troughing entering the
Pacific NW. As such, H5 heights within the forecast area have eroded
into a 584-588dm range providing slight cooling versus yesterday,
and most pronounced over the western CWA. Otherwise, only a narrow
midlevel moisture band associated with Baja shortwave will pass
through the region with some virga (and possible erratic winds) as a
result.

Over the next couple days, high pressure aloft will further be
displaced eastward with a progressive flow pattern resulting in
additional modest heights falls across the SW Conus. Some measure of
weak troughing/quasi-zonal flow will prevail over the region with H5
heights generally hovering in a 580-584dm range. Ensemble guidance
spread is rather narrow leading to excellent forecast confidence of
high temperatures mostly 6F-8F above normal, while clear skies and a
dry airmass promote efficient nocturnal cooling and lows not far
from climatology. This pattern of weak troughing/height falls will
support deep mechanical mixing and gusty afternoon winds, though
nothing unusually strong for mid May.

&&

.LONG TERM /Friday through Tuesday/...
The weather pattern later this week is expected shift to a more
zonal westerly dry flow pattern, but with some influence from
passing troughs to our north. The drying flow will result in clear
to mostly clear skies Friday-Saturday with temperatures remaining
quite stable averaging 5-7 degrees above normal. Ensembles are
currently favoring a larger Pacific trough moving through the
Pacific Northwest this weekend bringing lower heights as far south
as the Southwestern U.S. NBM/WPC temperature guidance suggests
daytime highs falling back more into the upper 90s by around Sunday.
Otherwise, daytime gusty winds will return to the region over the
weekend in association with the aforementioned trough passage.

&&

.AVIATION...Updated at 2325Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Occasional gusty winds under mid/high cloud decks will be the
primary aviation weather issue throughout the TAF period. Winds
through this evening will maintain a westerly component with
occasional gusts between 20-25 kts through the early to mid-
evening hours before gusts subside overnight with an easterly
switchover anticipated. Before the typical westerly switchover
Wednesday afternoon, a period of southerly crosswinds between 8-12
kts is anticipated during the late morning/early afternoon hours.
Occasional gusts upwards of 20-25 kts are anticipated once again
Wednesday afternoon, strongest near KIWA.

Southeast California/Southwest Arizona including KIPL and KBLH:
Periods of gusty winds under mostly clear skies will be the
primary aviation weather issue throughout the TAF period. At KIPL,
southeasterly winds will switch to a westerly component early
this evening and remain out of the west throughout the rest of the
period. At KBLH, winds will generally maintain a south to south-
southwest component throughout the period. Wind gusts between
20-30 kts will be common through early this evening before
weakening overnight aob 10 kts. Another period of gusty winds
upwards of 20-25 kts is anticipated once again Wednesday
afternoon.


&&

.FIRE WEATHER...
Hot, dry, and locally breezy to windy conditions will result in
elevated fire weather potential this afternoon across the Lower CO
River Valley. Wind gusts of 20-30 mph along with RHs 7-10% are
expected across the Lower CO River Valley. Elsewhere today, winds
will be lighter but with afternoon gusts of 15-20 mph possible.
Wednesday will bring another round of breezy winds over southeast
California and the Arizona high terrain with elevated fire weather
conditions again a possibility. Temperatures today will be 10-15
degrees above normal dropping to 5-8 degrees above normal starting
Wednesday. Winds will diminish starting Thursday, but very dry
conditions will continue to prevail.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Extreme Heat Warning until 8 PM MST this evening for AZZ537-540-
     542>544-546-548-550-551.

CA...None.
&&

$$

SHORT TERM...18
LONG TERM...Kuhlman
AVIATION...Lojero
FIRE WEATHER...Kuhlman