303
FXUS65 KPSR 142108
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
208 PM MST Tue Jul 14 2026

.KEY MESSAGES...

- Hot and muggy conditions will continue through mid week,
  particularly across southeast California and southwest Arizona
  where Extreme Heat Warnings have been issued through Thursday.

- Shower and thunderstorms chances will be fairly limited this
  afternoon and evening, but increase again for Wednesday.

- A disturbance will help to bring more widespread shower and
  thunderstorm activity on Thursday and Friday with the potential
  for heavy rainfall and localized flooding over eastern and
  central Arizona.

- Temperatures will cool later this week with below normal
  readings across much of Arizona to near normal for southeast
  California by Friday.

&&

.SHORT TERM /Today through Wednesday/...
Current upper-air analysis reveals an anomalously strong area of
high pressure stretching from the Great Lakes to the Rockies.
Although not a typical setup, this pattern has helped provide the
moist southeasterly flow needed to shift our monsoon season into a
higher a gear. Multiple rounds of showers and thunderstorms have
been seen across a good chunk of Arizona since this past weekend,
and it looks like activity will continue through at least the
middle portion of next week. How much convection develops will, of
course, depend on what occurs the day before, so future chances
are conditional, but nonetheless, PoP chances stretch into next
Tuesday.

Focusing more on the near term, like what was just stated above,
today looks to be more of a down day in terms of convective
activity, especially across lower desert areas of south-central
Arizona after what occurred yesterday evening. The atmosphere is
decently turned over so it will be much more difficult to overcome
any remaining cap in place by this afternoon. Best chances to see
storms across any span of desert are only 10-20% and will be focused
around the enhanced terrain of far southern Maricopa County and the
Kofas. A rouge storm cannot be completely ruled out for the
population centers of Maricopa and Pinal Counties, but any activity
will be heavily dependent on strong enough outflows descending off
the mountains, which appears unlikely at this time.

Better convective coverage is expected for Wednesday as atmospheric
instability starts to recover. Along with better coverage, average
storm intensity is expected to be greater as well creating a more
favorable setup to see stronger and longer lived outflows that
could descend into the lower deserts off the high terrain. Hi-res
data indicates typical initiation along the Mogollon Rim and the
mountains of Gila County before activity shifts down toward
Maricopa and Pinal Counties. It is tough say exactly who in the
lower elevations may see rain, given the spotty nature of monsoon
activity, and it is likely that some will see no rainfall at all.
With that being said, for the Phoenix metro and surrounding areas,
PoPs are around 20-30% to reflect the uncertainty of where cells
may flare up. Main impacts with this round would be heavy
downpours and winds greater than 35 mph. With upper-level flow
out of the northeast, widespread blowing dust appears to be less
of a concern, but the potential for some patches of reduced
visibility cannot be completely ignored.

For today, afternoon highs should be fairly uniform across the
lower deserts with readings climbing to between 102-110 degrees.
The region basically becomes split in half for Wednesday, with
near normal temperatures for south-central Arizona, likely thanks
to cloud and rainfall coverage, while locations in the drier,
western portion of our forecast area reach toward 115 degrees.
Although it may be drier in SW Arizona and SE California, since
no widespread rainfall is expected, is certainly will not feel dry
as dew points sit in the upper 50s to lower 60s. This will
produce heat indices between 110-116 degrees, and keep overnight
lows elevated in the lower to upper 80s, which would be near
record high minimums. To account for these conditions, an Extreme
Heat Warning is in effect for areas along the Colorado River and
westward through the next few days.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Active monsoon weather is expected to continue through the period
with Thursday and Friday showing the highest potential for impactful
weather. An important ingredient for more organized showers and
thunderstorms is expected to be introduced by Thursday. A large
easterly disturbance will continue to track across Texas into New
Mexico Wednesday into Thursday before stalling out over New Mexico
on Friday. This is expected to place at least the eastern half of
Arizona in a favorable ascent region for Thursday and Friday, and
potentially into Saturday.

Thursday has the better odds of being the best convective day as we
are anticipating the highest instability to go along with the upper
level support. However, there are hints of early morning rainfall
moving through areas east of the Colorado River. Hi-res data
shows a remnant MCV riding along the northeasterly flow, sparking
this morning activity and potentially throwing the typical late
day storm timeframe into doubt if lingering cloud cover limits
instability. As of now, forecast soundings still show upwards of
1000 J/kg of CAPE for Phoenix, a good indication that the
environment will remain favorable for robust afternoon/evening
thunderstorm activity. Additional moisture transport into the
region should also push PWATs to between 1.8-2.1", suggesting
heavy rainfall will an increasing threat. NBM PoPs increase to
70-80% for eastern and south-central Arizona Thursday, while WPC
has introduced a large Slight Risk for excessive rainfall. We will
continue to monitor the latest guidance as Flood Watches are
likely to be needed for some areas later this week. Shower and
thunderstorm chances should also expand westward toward the Lower
CO River Valley Thursday night with chances continuing areawide
through at least Friday. As of now, a Slight Risk for excessive
rainfall is also present for Friday, but the uncertainty is higher
as instability is likely to be lower and the easterly wave should
begin weakening on Friday. With all this being said, the forecast
is highly conditional on what happens Thursday morning.

Abundant monsoon moisture will persist over the weekend into early
next week with day-to-day storm chances continuing, but forecast
uncertainty is quite high. Another easterly wave looks to be
possible at some point during the first half of next week which may
bring another round of higher storm/rainfall coverage.

Forecast temperatures for later this week into next week are also of
low confidence due to the expected convective potential over much of
the area. The latest NBM forecast highs show readings dipping below
normal over the south-central Arizona lower deserts as early as
Thursday, but remaining right around normal for the western deserts.
Although model forecast spread for temperatures is quite high
beginning Thursday, it seems likely the Phoenix area will see at
least a day or two in the 90s on Friday and/or Saturday. Depending
on the amount of cloud coverage and even morning/afternoon rainfall
on Friday, highs may struggle to reach the low to mid 90s.

&&

.AVIATION...Updated at 1700Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Winds will be the main weather issue through Wednesday afternoon
under periods of mid/high cloud decks. Directions may remain
variable into early this afternoon before settling on a W/SW
direction. Mountain thunderstorms should be less pronounced today,
and likely not descending into the terminal footprint. Even outflow
winds may not impact all terminal locations, and there is large
uncertainty regarding the timing of an easterly wind shift
overnight. Have pushed back timing of an easterly shift, and it`s
not impossible that KPHX never truly turns east, and just becomes
variable for a few hours Wednesday morning.

Wednesday evening outlook: Chances for stronger, gusty easterly
outflow winds and direct TS impacts will increase substantially late
afternoon/early Wednesday evening. Brief periods of MVFR/IFR
visibility in TSRA are possible early/mid evening.

Southeast California/Southwest Arizona including KIPL and KBLH:
No major weather issues will exist through Wednesday afternoon under
periods of mid/high level cloud decks. Winds will generally vary
from a diurnal SE component to a nocturnal SW direction. Any gusts
will be limited and directions may become variable for a period
around sunrise.

&&

.FIRE WEATHER...
Elevated moisture levels will result in daily chances for showers
and thunderstorms over the eastern districts through Wednesday
before increasing in coverage and spreading westward late week.
Humidities will continue to improve through the rest of the week,
while temperatures eventually cool to around or even below normal by
Thursday. MinRHs are expected to hover between 20-30% over the lower
deserts to 30-40% over the AZ high terrain through Wednesday before
improving further late week. Outside of potential thunderstorm
outflows, winds will tend to be light and somewhat favor diurnal
trends.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Extreme Heat Warning until 8 PM MST Thursday for AZZ530-532.

CA...Extreme Heat Warning until 8 PM PDT Thursday for CAZ562-563-
     565>567-569-570.

&&

$$

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