026
FXUS65 KPSR 170945
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
245 AM MST Thu Jul 17 2025

.KEY MESSAGES...

- Chances for scattered showers and isolated thunderstorms will
  continue mainly this morning across southwest Arizona.

- Drier conditions into the weekend will limit any rain chances
  to the eastern Arizona high terrain.

- Near to below normal temperatures are forecast to persist
  through at least the middle of next week with lower desert
  highs mostly between 101 and 106 degrees each day.

&&

.SHORT TERM /Today through Friday/...
The remnant MCV from yesterday morning is still the main driving
force of shower activity with a fairly large area of showers and a
few embedded thunderstorms encompassing much of southwest Arizona
into western Maricopa County. This activity should yield rainfall
amounts upwards of 0.50-0.75" in some locations through sunrise
this morning. The upper level low is finally making progress
northward with the center now just off the coast of central Baja.
Southerly flow on the eastern fringes of the low is also starting
to bring dry air northward through Sonora with this dry air slated
to push through much of southern and central Arizona by this
afternoon. Once we lose the support from the MCV and any remaining
instability over southwest Arizona, we are not expecting anything
other than a few isolated convective showers this afternoon. PoPs
have been curtailed considerably from the NBM baseline as Hi-Res
CAMs show little if any activity after sunrise today.

The extensive cloud shield will also get eroded from south to
north by mid to late morning with much more sunshine expected this
afternoon compared to yesterday. Temperatures will in turn
respond by warming to just above 100 degrees for the majority of
the lower deserts this afternoon.

Dry air is forecast to continue spreading into the region from the
south on Friday as the weakening upper level low likely shifts
into southern California by Friday afternoon/evening. There may be
enough lingering moisture for some isolated showers or maybe a
thunderstorm or two west of the Phoenix area and over the eastern
Arizona high terrain, but once again the convection should be very
limited. Temperatures Friday will continue to warm as we dry out
with highs likely topping out at around 105 degrees across the
lower deserts.

&&

.LONG TERM /Saturday through Wednesday/...
Guidance continues to show overall quiet and not so hot weather
conditions this weekend through the first half of next week.
Southwesterly dry flow is likely to persist at least into next
Monday with only meager amounts of moisture over eastern Arizona.
This should be enough to bring some daily chances (10-30%) for
isolated showers and thunderstorms over eastern Arizona, but
chances over the lower deserts are generally less than 10%.
Chances may improve slightly by Monday or Tuesday as guidance
shows some additional moisture drifting northward out of Mexico,
but overall moisture is not likely to be very plentiful and there
are no discernible features within the models to help bring
anything other than the typical afternoon mountain convection.
The synoptic pattern is rather stagnant over the weekend and
through the first half of next week with a large trough sitting
just to our northwest and the subtropical ridge mostly over the
Southern Plains. Model trends over the last couple of days have
actually showed the upper low having more of an influence on our
region keeping our temperatures from warming up any further. The
latest NBM forecast highs through the middle of next week keep
readings right at or even a couple degrees below normal. This
should keep the HeatRisk over our area anywhere from high-end
Minor to low-end Moderate.

&&

.AVIATION...Updated at 0600Z.

South Central Arizona including KPHX, KIWA, KSDL, KDVT:
Showers continue to develop west of Phoenix this evening with a
few weak echoes showing up into parts of the metro. Expect the
bulk of any shower activity to remain west of the terminals, but
may see a few vicinity showers pop up in the metro going into the
overnight hours. Can`t rule out an isolated thunderstorm, but
confidence is too low to have any mention in the TAFs. Winds going
into the overnight hours will continue to favor the E-SE, but may
temporarily favor the N-NE with an outflow pushing southward into
the Valley this evening. Expect some light and variable winds
overnight to give way to westerly winds later Thursday morning.
FEW-SCT clouds down to around 7-8 kft are expected going into the
overnight hours, especially with any shower/thunderstorm activity
that were to materialize, but otherwise SCT-BKN mid and high
clouds will continue throughout the rest of the period.

Southeast California/Southwest Arizona including KIPL and KBLH:
Winds will continue to predominantly favor the SE through the
period at KIPL, while winds mostly favor the S at KBLH. Expect
some VCSH near KBLH overnight tonight as shower/thunderstorm
activity pushes westward across southwest Arizona. Can`t rule out
an isolated thunderstorm as well near KBLH, but have not added
mention of this at this time due to low confidence. SCT-BKN
clouds mostly aoa 10 kft are expected throughout the period.

&&

.FIRE WEATHER...
Below normal temperatures and increased humidities will continue
today before drying occurs Friday into the weekend. Expect
scattered showers and a few isolated thunderstorms today with very
limited chances on Friday. Afternoon MinRHs will stay between
25-30% today before dropping closer to 20% Friday and into the
teens this weekend. Winds over the next few days should mostly
follow diurnal patterns with only light periodic breezes in the
afternoon. High pressure will somewhat return to the region this
weekend with RHs dropping back into the teens, but temperatures
will at most return to normal. Any rain chances should be quite
limited and only over the eastern Arizona high terrain.

&&

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

$$

SHORT TERM...Kuhlman
LONG TERM...Kuhlman
AVIATION...Smith
FIRE WEATHER...Kuhlman