816
FXUS65 KPSR 111736
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1036 AM MST Fri Jul 11 2025

.UPDATE...Updated 18Z Aviation Discussion

&&

.KEY MESSAGES...

- Dry conditions will prevail across the forecast area through the
next several days with only isolated thunderstorm activity over the
eastern Arizona high terrain this weekend.

- Temperatures will be fairly stable through early next week,
generally a few degrees above daily normals with lower desert highs
around 105 to 110 degrees.

- A better monsoon pattern for south-central Arizona sets up next
week allowing thunderstorm activity to increase over eastern Arizona
high terrain initially, then slight chances descending into lower
desert communities by the latter half of the week.

&&

.SHORT TERM /TODAY THROUGH SATURDAY/...
The zonally elongated subtropical high that sat almost directly
overhead yesterday continues to retrograde westward early this
morning, with current 500 mb RAP analysis placing its center just
off the Northern Baja/SoCal Coast. With the influence of the high
diminishing as it slides off to the west, a fairly strong gulf surge
was able to occur, spreading over South-Central AZ and helping to
increase dewpoint temperatures upwards of 60-65F so far early this
morning. Further west across the Yuma area and Imperial Valley,
dewpoint temperatures in excess of 70F have been observed. Though
this is quite a shallow layer of moisture, radiative cooling at the
surface will not be as efficient, making for another unusually warm
morning. Forecast morning lows across the lower deserts are in the
80s and even lower 90s in central Phoenix this morning. Though
different models show some discrepancies in the exact placement and
strength of the aforementioned subtropical high as we head into this
weekend, H5 heights are likely to fall in a 592-595 dam range
through the next few days, maintaining slightly above average values
for the time of year. This will translate to afternoon highs
generally a few degrees above daily normals today and Saturday,
around 105-110 for the lower deserts.

Thunderstorm activity will remain minimal across the state through
Saturday, with the latest HREF membership showing essentially no
convection this afternoon except near the international border in
Cochise County. This is in large part due to dry, west northwest
flow aloft today that will turn more northerly by Saturday,
effectively scouring out moisture in the midlevels. In fact, PWATs
are expected to drop below one inch across the entire forecast area
by late Saturday. Despite this fact, some lingering low level
moisture looks like it will be sufficient to spark high terrain
convection Saturday along the Rim, White Mountains, and far
Southeast AZ, but quite isolated in coverage.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
By Sunday, ensembles hint at another high beginning to develop north
of the area, turning the midlevel flow from north to northeasterly.
This second high will likely develop into a Four Corners high later
in the week. Latest guidance suggests a slight uptick in afternoon
thunderstorm activity over the Eastern AZ high terrain Sunday, with
a similar level of activity being maintained each day through
Tuesday. Meanwhile, ensembles show PWATs gradually increasing over
Southern AZ, with mean values upwards of 1.25-1.50" by the middle of
the upcoming workweek. This would lead to gradually increasing
convective coverage over the Southeastern third of the state. By
Wednesday-Thursday, the high pressure aloft is also anticipated to
slide over the Four Corners, which would help turn the flow east and
then southeast over the forecast area. This could prove a much more
favorable setup for monsoon thunderstorm activity for South-Central
AZ in this situation, as we start the week rather moisture-starved,
and better quality moisture will be situated to the south. With this
evolution in mind, convective coverage will be on the increase
across the higher terrain and foothills initially before chances
increase across the lower deserts, more likely by the latter half of
the week. A lot of details are still uncertain this far out, but the
preponderance of ensemble guidance would suggest that some monsoon
thunderstorm impacts (likely strong, gusty outflow winds and dust at
first) will be possible across South-Central AZ late next week.

Temperatures will moderate closer to mid-July normals by the middle
of the upcoming workweek as moisture gradually increases and H5
heights aloft fluctuate around 591 dam, near the climatological
average for this time of year. As such, the latest NBM shows a
continuation of lower desert highs in a 105-110 degree range through
Monday, dropping into a 102-108 degree range by midweek.

&&

.AVIATION...Updated at 1735Z.

South Central Arizona including KPHX, KIWA, KSDL, KDVT:
Occasionally gusty winds this afternoon will be the main weather
issues through Saturday morning under clear skies. Gusts can
expect to be between 20-25kts throughout this afternoon into the
evening. W/SW winds will be dominate through most of the TAF
period with potential for an easterly shift tomorrow morning at
KPHX.

Southeast California/Southwest Arizona including KIPL and KBLH:
No significant weather issues will exist through Saturday morning
under clear skies. Confidence is good that KBLH will maintain a
general south wind through the period with afternoon gustiness.
Winds at KIPL will be similar to the past 24 hours varying between
a daytime SE component and evening/overnight SW direction.

&&

.FIRE WEATHER...
Above normal temperatures and dry conditions will persist through
the weekend. This afternoon, gusts upwards of 25-30 mph will be
mostly confined to the high terrain of the eastern districts.
Elsewhere, anticipate typical afternoon upslope breeziness for the
time of year. Afternoon minRHs will generally bottom out between 15-
20% areawide today and Saturday, and overnight recoveries will
generally range between 40-60% tonight and drop to 30-50% Saturday
night. Very minimal rain chances will exist through this weekend,
with activity focused mainly across the Eastern AZ high terrain  and
southeastern third of AZ, with CWR <10%.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&

$$

SHORT TERM...Whittock
LONG TERM...Whittock
AVIATION...Ryan/18
FIRE WEATHER...Whittock