038
FXUS65 KPSR 310501
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1000 PM MST Thu Jul 30 2026

.UPDATE...
Updated Aviation

&&

.KEY MESSAGES...

- Extreme heat will build over the region the next few days lasting
through at least the weekend. Near record high temperatures will
impact the region Friday through Sunday.

- In response to the very hot conditions, Extreme Heat Warnings are
in effect regionwide through Monday.

- Drier air over the region will confine any chances for showers and
thunderstorms over far eastern Arizona high terrain areas through at
least Sunday.

&&

.SHORT TERM /Today through Friday/...
Current objective analysis reveals the center of the sub-tropical
high continuing to hover over New Mexico as it begins to strengthen.
500mb RAP analysis suggests peak heights have reached around 597dm,
but further amplification is expected through the end of the work
week. Ensembles continue to suggest that heights aloft will peak
around 598-600dm by Friday, which would be near climatological
records for this time of year, to put how strong this area of high
pressure will be into perspective. This setup will translate to very
hot conditions regionwide, with afternoon highs between 108-116
degrees being common across the lower desert today and once again
Friday. In response, Extreme Heat Warnings have gone into effect and
will continue into at least the start of next week.

The presence of weak troughing over the western CONUS helped pull in
some relatively dry air (at least for this time of year), which has
greatly limited monsoonal activity potential. Dew points have fallen
into the lower and middle 50s for a good chunk of our forecast area,
with some locations even seeing readings in the middle 40s. This is
much lower compared to where we were 48 hours ago, when middle 60s
and lower 70s were more common. Taking a look at the atmospheric
columns as whole, PWATs have taken a decent hit too, now ranging
between 0.5" over far western portions of our CWA, to around 1.2-
1.3" across south-central Arizona. Moisture profiles do no support
much in the way of showers and thunderstorms, both today and
tomorrow, even across the vast majority of Arizona but a few
convective cells cannot be completely ruled out for southeastern
portions of the state and the White Mountains, but coverage will be
very limited.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Model ensembles have changed little from yesterday`s runs showing
the peak of the ridge and temperatures occurring on Saturday before
the ridge weakens Sunday into Monday. NBM foreast highs have come
down a degree or so from yesterday, but it is hard to find a good
reason why. Forecast confidence remains high that some daily heat
records are likely to be broken this weekend with southeast CA lower
deserts reaching 115-120 degrees to 113-117 degrees across the
Arizona lower deserts. To give some prospective, Phoenix has only
reached 116 degrees or higher 18 times after July 30th, half of
which occurred since 2023 and only reached 117 degrees or higher 6
times. The probability of KPHX hitting at least 116 degrees Friday-
Sunday is 20%, 67%, and 35% respectively. For Saturday, the NBM also
shows a 20-25% probability of tying the all-time hottest temperature
in August of 118 degrees which occurred August 7, 2025. We will have
some relief from the extreme heat at night, more so across the
western deserts where lows should still dip into the mid to upper
80s. The bulk of the Phoenix metro should have lows only in a 90-95
degree range Friday-Sunday.

Any potential rain chances over the weekend are trending even lower
with guidance mostly showing any decent moisture advection holding
off until late Sunday into Monday. Some members still show some
improved chances over the eastern Arizona high terrain convection as
early as Sunday with potential for outflows into the Phoenix area
Sunday evening, but it seems more likely that will not occur until
Monday at the earliest. Guidance does agree on the ridge noticeably
weakening by Monday with H5 heights dropping to 594-596dm, but the
residual heat over the region is expected to keep extreme heat
conditions around through Monday. The ridge center should also begin
to drift back to the northeast, closer to the Four Corners area by
around next Tuesday. If and when this happens, it should open up
portions of the region for better moisture advection out of the
southeast. Monsoon storm chances are expected to gradually improve
going into the middle of next week, while NBM forecast highs drop
back to within a few degrees of normals.

&&

.AVIATION...Updated at 0500Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No significant weather concerns will exist through Friday night
under periods of mid/high cloud decks. Uncertainty continues
regarding wind forecasts for a couple periods. Initially, directions
may not make the full easterly switch late tonight, though a distant
outflow from southern Arizona may force a wind switch just prior to
sunrise. Confidence is very good that west winds will return by late
morning with some modest gusts in the afternoon. There is a chance
winds gusts somewhat more substantially late Friday evening though
directions will remain W/SW yielding only minimal operational
impacts and confidence is too low to include in this TAF package.


Southeast California/Southwest Arizona including KIPL and KBLH:
No significant weather issues will exist through Friday night under
mostly clear skies. Trends in winds should be similar to the past 24
hours featuring a preference towards a southerly direction at KBLH
and SE at KIPL. Variability may become common during the morning
hours while some modest afternoon gusts will be possible at KBLH.

&&

.FIRE WEATHER...
Strong high pressure will gradually build over the region through
the rest of the week while increasingly dry air confines any rain
chances to over far eastern Arizona. Expect humidities to continue
to lower over the next couple of days with MinRHs settling at 10-15%
by Friday, while falling overnight RHs offer only little to modest
relief. Record to near record temperatures are also forecast for
Friday and through the upcoming weekend. Winds will mostly follow
diurnal patterns, but west southwesterly winds will be dominant much
of the time with afternoon gusts of 15-20 mph at times.

&&

.CLIMATE...
Record high temperatures:

Date       Phoenix         Yuma         El Centro
----       -------         ----         ---------
Jul 31   116 in 2020    119 in 1957    119 in 2020
Aug 1    116 in 1972    117 in 1993    118 in 1993
Aug 2    114 in 2025    117 in 1918    117 in 1969
Aug 3    116 in 2024    116 in 1998    117 in 2021

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Extreme Heat Warning until 8 PM MST Monday for AZZ530>563.

CA...Extreme Heat Warning until 8 PM PDT Monday for CAZ560>570.

&&

$$

SHORT TERM...RW
LONG TERM...Kuhlman
AVIATION...18
FIRE WEATHER...Kuhlman
CLIMATE...18