076
FXUS65 KPSR 140520
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1020 PM MST Mon Jul 13 2026

.UPDATE...06Z Aviation Discussion.

&&

.KEY MESSAGES...

- A fairly typical Monsoon pattern will continue through the
  first half of the week, with early afternoon showers and
  thunderstorms forming over the Arizona high terrain daily
  followed by chances over the lower deserts focused later in the
  afternoon into the evening.

- A disturbance may approach the region from the east during the
  latter half of the week, bringing favorable conditions for more
  widespread showers and thunderstorms.

- Seasonably hot temperatures will persist through the middle of
  the week resulting in widespread Moderate Heat Risk and locally
  Major Heat Risk on Wednesday in Southeast California, followed
  by cooler temperatures late week.

&&

.SHORT TERM /TODAY THROUGH TUESDAY/...

As of 1:13 AM MST this morning Phoenix Sky Harbor was able to
measure with a total of 0.01", the first measurable rainfall since
March 29th, 2026. Many surrounding areas in the Phoenix Metro were
also able to measure between 0.01"-0.05" while areas in southern
Maricopa County, Pinal County and the higher terrains received
measurements between 0.25"-0.75" to locally higher amounts. This was
due to a cluster of severe thunderstorms that developed in southern
Maricopa County and Pinal County yesterday evening. While
measurable rainfall is always exciting, especially here in the
lower deserts, that was not the highlight of yesterdays activity as
those areas, and even into the West Valley, received their first
Dust Storm Warning since September 26th, 2025. The storms that
developed were able to produce southeasterly gusts up to 45-50 mph
at times, picking up a large amount of dust and reducing visibilities
to under 1/4 of a mile to near zero in some areas last night.

Today GOES mid-level WV imagery shows the high pressure over the
Northern Plains associated with a large area of dry air. The
position of this high pressure is what has shifted flow aloft over
the Desert SW out of the southeast, and allowing for good moisture
advection. This increase in moisture has lead to PWATs between 1.5"-
1.8" across a vast majority of the CWA with locally higher, closer
to 2", near the Gulf of California. This moisture is expected to
linger throughout the week with 1000mb-700mb mixing ratios staying
generally between 10-12 g/kg across the region. With yesterday`s
activity the atmosphere is slightly worked over resulting in
chances today for activity to be lower, however not zero, with
PoPs between 15-25% in the Metro, and between 30-50% in the
Foothills. The latest HRRR run does show another round of storms
developing today in much of the same areas as yesterday (eastern
high terrain and South central AZ), however winds are expected to
be lower this afternoon with the HREF guidance showing only a
50-70% chance (compared to Sunday`s 70-90%) of winds above 35 mph
focused along a corridor from Phoenix south/southeastward, and not
near as widespread comparatively. Additionally with yesterdays
rainfall dust may not be as easily lofted, hindering chances for
widespread blowing dust tonight. Any activity that does form in
our region tonight will continue to be highly conditional on
upstream activity and if outflows from Central AZ high terrain
storms can trigger additional cells. By Tuesday, thermodynamics
may be slightly more favorable for strong storms, however, flow
aloft weakens further and directions become complex as weak
anticyclonic and cyclonic circulations begin to impinge on the
region, creating a deformation area. The threat for lower desert
storms will be even more conditional on lifting mechanisms from
earlier storms or subtle lift from the deformation zones draped
across the region.

Otherwise, temperatures this afternoon will be in the low to mid
100s across the lower deserts, with the Phoenix Metro slight higher
between 105F-107F. Tuesday`s afternoon highs will be slightly
warmer, with temperatures ranging between 105F-111F. Despite the
story weather these temperatures are still a few degrees above normal
keeping widespread Moderate HeatRisk in place. With that said, be
sure to keep heat safety in mind if spending time outdoors.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
There is still excellent agreement within the EPS and GEFS
members regarding the placement of the upper high over the
northern Plains and Upper Midwest through midweek before
retrograding over the central Rockies by the latter half of the
week. The overall position of the 500 mb high will maintain deep
easterly flow across the Desert Southwest, helping enhance
moisture transport. Latest EPS and GEFS continue to show PWATs
hovering around 1.5"-1.8" through the entire week with low-level
mixing ratios remaining between 10-12 g/kg. Therefore, conditions
will continue to remain conducive for daily thunderstorm activity
with variations in the overall coverage. Both the mean of the EPS
and GEFS show an uptick in QPF across the region by the end of
this week due to an easterly wave/inverted trough approaching the
area by Thursday-Friday. If this occurs, this troughing feature
will likely enhance convective activity potentially introduce a
risk for heavy rainfall across portions of AZ. This will have to
be monitored closely in the coming days.

Temperatures are expected to peak Wednesday mostly between
105F-110F across the Arizona lower deserts, but some areas of
Major HeatRisk enter the picture for portions of Southeast CA and
along the Lower Colorado River Valley, where latest NBM forecast
shows highs as high as 113F and lows in the middle to upper 80s
thanks to the inefficient overnight radiative cooling from higher
humidity and likely some mid-high cloud cover. The NBM continues
to indicate temperatures cooling to well below normal by the end
of the week with highs falling into the 90s to around 100 degrees
across the lower deserts by Friday. This is likely due to the
increased signal for thicker cloud cover and the potential for
more widespread rainfall.

&&

.AVIATION...Updated at 0515Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
After widespread strong gusty winds and thunderstorm activity
earlier this evening, conditions are improving across the area.
Conditions through Tuesday afternoon should remain tranquil with
the overall wind pattern following the typical diurnal tendencies
with easterly winds overnight through early Tuesday morning
shifting out of the west late Tuesday morning/early afternoon with
some occasional afternoon gusts in the mid to upper teens. At this
time, there is a much lower chance of thunderstorm activity
Tuesday evening with a better potential of an easterly outflow
from distant activity. Outflow magnitude will be all dependent on
the overall coverage and intensity of distant storm activity. SCT
to occasional BKN mid to high clouds will prevail through the
overnight hours before coverage decreases to FEW by Tuesday
morning.

Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation concerns are expected throughout the TAF period
under FEW to SCT mid to high clouds. At KIPL, light and variable
winds currently will shift out of the southeast by early Tuesday
morning and remain out of the southeast through the afternoon
hours with another temporary shift out of the west during the
early evening hours. At KBLH, winds will generally fluctuate
between the south-southeast to southwest with a period of light
variability Tuesday morning. Overall wind speeds are expected to
remain aob 10 kts.

&&

.FIRE WEATHER...
Seasonably hot temperatures will prevail through the next several
days as readings will be near to slightly above normal. Daily
thunderstorm activity will be possible through this week with the
potential for more widespread wetting rainfall increasing across
the eastern districts throughout this week, with higher chances by
Thursday and Friday. Due to increasing boundary layer moisture,
afternoon humidity levels will remain in a 20-30% range which will
keep any fire weather concerns at a minimum. Overnight recoveries
will be fair to good, or between 40-70%. Outside of any
thunderstorm driven outflow, winds should favor diurnal trends
with the typical afternoon breeziness around 20-25 mph.

&&

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

$$

SHORT TERM...Ryan/Whittock
LONG TERM...Salerno/Whittock
AVIATION...Lojero
FIRE WEATHER...Ryan/Whittock

NWS Phoenix (PSR) Office