065
FXUS65 KPSR 180004
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
504 PM MST Thu Jul 17 2025

.UPDATE...Updated Aviation Discussion.

&&

.KEY MESSAGES...

- Slight chances for isolated to scattered showers and isolated
  thunderstorms will continue across the region.

- 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 100 and 107 degrees each day.

&&

.NEAR TERM /Rest of Today and Overnight/...
The remnant MCV from yesterday morning has moved up into west-
central portions of AZ. The upper level low, off the coast of
central Baja, is finally making progress northward. Southerly flow
on the eastern side of the low has brought dry air northward
through Sonora, our PWATs have fallen from around 1.8" this
morning to around 1.6" for the Phoenix area. Lower moisture
(1.0-1.2") is seen further east in Gila county with higher
moisture (1.8-2.0") over southeastern AZ and southwestern AZ,
where the MCV is located. A shortwave trough, on the east side of
the low, has moved up into central portions of AZ. This shortwave
has produced some lift for a few isolated showers and storms in
south- central AZ, but these showers and storms have struggled to
reach into the Phoenix area. However, some more isolated activity
is possible, even in the Phoenix Metro, as this shortwave continue
to progress northward. Additional shower and storm activity is
out in SE CA and SW AZ. But, these are associated with the remnant
MCV. All of these showers showers should stay sub-severe, but
they could produce some gusty outflow boundary`s when they
collapse which could produce some areas of blowing dust. Slight
shower and storm chances will continue into the overnight hours.
Less cloud cover this afternoon have allowed temperatures to be a
little bit warmer today. Sky Harbor has already reached 100
degrees by 3pm this afternoon.

&&

.SHORT TERM /Friday/...
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 0004Z.

South Central Arizona including KPHX, KIWA, KSDL, KDVT:
Radar this afternoon showed showers and isolated thunderstorms
across southern Maricopa County and areas to the west. Expect this
activity to mostly remain to the south and west of the metro
through this evening. Can`t rule out an outflow making it into the
metro this evening, but the likelihood of this occurring is low.
Winds will otherwise remain light, outside of afternoon gusts
upwards of 15-20 kts, with directions favoring the west
throughout much of the period. Not expecting a typical diurnal
easterly shift at KPHX overnight tonight with light and variable
winds favored instead. Otherwise, expect FEW-SCT clouds aoa 8-10
kft.

Southeast California/Southwest Arizona including KIPL and KBLH:
Isolated showers/thunderstorms will be possible this evening, but
chances remain too low (5-10%) to warrant mention in the TAFs at
this time. Any thunderstorms that were to develop near the
terminals would be capable of producing gusty erratic winds.
Winds will otherwise continue to predominantly favor the E-SE at
KIPL and S at KBLH. FEW-SCT, and at times BKN, clouds are expected
aoa 10 kft throughout the period.

&&

.FIRE WEATHER...
Expect scattered showers and a few isolated thunderstorms today,
mainly over terrain features, with very limited chances tomorrow
and through the weekend. Any shower or storm activity on Friday
and Saturday will be confined to the higher terrain to the east of
Phoenix. For the first half of next week shower and storm chances
increase again, with less than 20% for the south-central AZ lower
deserts. Afternoon MinRHs drop to around 15-20% Friday, then
10-20% this weekend, and slightly increase to 15-20% for the
beginning of next week. Winds should mostly follow diurnal
patterns with only light periodic breezes in the afternoons and
early evenings.

&&

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

$$

NEAR TERM...Berislavich
SHORT TERM...Kuhlman
LONG TERM...Kuhlman
AVIATION...Smith
FIRE WEATHER...Berislavich/Kuhlman