293
FXUS65 KPSR 240957
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
257 AM MST Wed Jun 24 2026

.KEY MESSAGES...

- Temperatures around five degrees above normal will result in
  widespread Moderate Heat Risk and localized Major Heat Risk
  through Thursday.

- Extreme Heat Warnings will remain in effect for portions of the
  area through Thursday.

- Drying conditions and a regional increase in winds late this
  week will result in areas of critical fire weather, and so Fire
  Weather Watches have been issued for the Lower Colorado River
  Valley and Tonto National Forest on Friday and Saturday.

&&

.SHORT TERM /TODAY THROUGH THURSDAY/...
A strong upper level high remains positioned across the region
with the center situated across far southwest New Mexico. Despite
the ridge being quite strong (near climatological record H5
heights) just to our southeast, plenty of mid and upper level
moisture has entrained into the system over the past couple of
days. Weak upper level shortwaves continue to flow around the
western fringes of the ridge passing through California, supported
by a persistent upper level jet situated from off the coast of
California into the Great Basin. Support from the upper level jet
will also continue to bring isolated 10% chances for showers
(mostly virga) and maybe a few rumbles of thunder today into
tonight.

The near record H5 heights of 596-598dm could support near record
temperatures, but we will fall well short over the next couple of
days due to marginally increased boundary layer moisture and
fairly abundant mid and high clouds. NBM forecast temperatures
for today and Thursday have struggled a bit over the past several
runs, initially discounting the potential impacts of the cloud
cover and showing potential for temperatures near 115 degrees.
The increased moisture and clouds today are expected to keep
daytime highs more in a 108-112 degree range, or 5-7 degrees
above normal, but very warm overnight lows well into the 80s for
many spots will make for little relief from the heat. Extreme
Heat Warnings are in effect for today through Thursday evening,
focused over urban locations. The ridge is expected to begin to
weaken later today into Thursday, but highs Thursday will
essentially mirror today`s readings. Drier air will also begin to
filter in from the west on Thursday resulting in gradually
clearing skies through the first part of the day.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Forecast concern will turn away from the Extreme Heat and toward
increasing fire danger as winds increase and much drier
conditions are expected by Friday. A large Pacific trough is
slated to gradually shift southeastward down the West Coast
Thursday into Friday, quickly pushing the subtropical high to the
south of the region. Persistent height falls from the incoming
trough are forecast on Friday and Saturday while a strong
gradient sets up across the Southwestern U.S. Winds will initially
become breezy as early as Thursday, but pick up even more on
Friday into Saturday. Guidance shows unseasonably strong gradient
winds setting up on Friday and lasting through at least Saturday
and potentially even into Sunday. Afternoon wind gusts of 20-30
mph should impact the entire area on Friday and Saturday with
locally higher gusts of 30-40 mph. Gradual drying of the boundary
layer will also lower daytime humidities to between 5-15% by
Friday. The combination of the low humidities and the strong gusty
winds are likely to make for dangerous fire weather conditions
starting Friday. A Fire Weather Watch is currently in effect for
the Lower CO River Valley and over the Arizona high terrain from
Friday morning through Saturday evening.

Although H5 heights decrease to below 590dm on Friday,
temperatures will be a bit slow to respond as highs will still
mostly top out in a 106-110 degree range. As the trough gets
closer and heights continue to fall through the weekend,
temperatures are expected to drop into the normal range as early
as Saturday and potentially even 4-7 degrees below normal starting
Sunday. The latest NBM/WPC forecast highs shows readings only in
a 99-103 degree range across southeast California to 100-105
degrees in the Phoenix area for Sunday-Tuesday.

&&

.AVIATION...Updated at 0955Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No major aviation concerns are expected during the TAF period. The
main uncertainty that remains is the wind direction at KPHX early
this morning. Westerly winds should mostly prevail, but a few hour
period of variable to even light easterly winds are possible. SCT-
BKN mid-level cloud cover will be common across the region through
this evening with some virga showers mainly staying west of the
terminals.

Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation concerns are expected during the next 24 hours
under SCT-BKN mid-level cloud cover. Winds will fluctuate between
a W`rly and SE`rly component at KIPL with some increasing gusts
during the afternoon. At KBLH, S`rly winds will persist, tilting
more to the SW by the afternoon.

&&

.FIRE WEATHER...
Locally elevated fire weather conditions due to low humidity and
afternoon upslope/upvalley breeziness will continue through
Thursday. Temperatures will be above normal, with afternoon highs
near or slightly above 110 degrees across the lower deserts.
MinRHs will be around 15% areawide today and decrease into the
single digits across the western districts starting Thursday.
Winds will generally remain terrain- driven, with
upslope/upvalley gusts during the latter half of the afternoon
into the early evening peaking around 20 mph today and 25 mph
Thursday. Areas of critical fire weather conditions are likely by
Friday and into this weekend as southwesterly winds increase
across the region. A Fire Weather Watch has been issued for the
Lower Colorado River Valley and Tonto NF/Southern Gila County
zones Friday-Saturday.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Extreme Heat Warning from 10 AM this morning to 8 PM MST
     Thursday for AZZ530-532-533-537-540-542>544-546-548-550-551.

     Fire Weather Watch from Friday morning through Saturday evening
     for AZZ131-133.

     Extreme Heat Warning until 8 PM MST this evening for AZZ560.

CA...Extreme Heat Warning from 10 AM this morning to 8 PM PDT
     Thursday for CAZ562-566-567-569.

     Fire Weather Watch from Friday morning through Saturday evening
     for CAZ231.

&&

$$

SHORT TERM...Kuhlman
LONG TERM...Kuhlman
AVIATION...RW/Kuhlman
FIRE WEATHER...Whittock/Kuhlman

NWS Phoenix (PSR) Office