472
FXUS65 KPSR 031953
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1253 PM MST Wed Jun 3 2026

.KEY MESSAGES...

- Above normal temperatures with moderate HeatRisk will prevail
  throughout the week before retreating closer to normal by the
  end of the weekend.

- Other than a slight chance of a shower or thunderstorm in
  eastern Arizona during the next few afternoons, dry conditions
  under mostly sunny skies will prevail through the weekend.

- Locally breezy conditions will develop late in the week and
  this weekend, particularly across the lower Colorado River
  Valley and higher terrain communities.

&&

.SHORT TERM /Today through Friday/...
Latest midday objective analysis shows very weak flow over the
region, with a bit of a col overhead. The weak coastal low is now
just off the central Baja Peninsula coast and should begin pushing
eastward this afternoon. H5 heights over the area are around
587dam, which is around the 75th percentile of climatology for
this time of year. This higher than normal height field and
pressure will result in above normal surface temperatures this
afternoon and the next few afternoons with limited change in the
synoptic pattern as the low slowly progresses east across
northern Mexico through the end of the week.

High temperatures this afternoon are forecast to reach up to
104-107F across the lower deserts, under sunny skies. These
temperatures will be around 4-6 degrees above daily averages.
Latest NBM forecast has increased high temperature forecasts for
tomorrow by 1-2 degrees over previous forecast packages and now
has some areas flirting with 110F, including in the Phoenix area
and Imperial Valley. High tomorrow are now forecast to reach
106-109F across the lower deserts. While it may still seem a
little early to see 110F it would not be uncommon. Daily records
are in the 112-116F range for early June. Forecast high
temperatures for Friday have also come up slightly from previous
forecasts and is now expected to be similar to today. These
temperatures will lead to widespread Moderate HeatRisk.

While most of the region will remain very dry and mostly sunny the
next few days, some low level moisture has moved into southeast
AZ. This moisture contributed to some convective showers in the
White Mountains yesterday and westward-propagating outflows from
these showers and storms in NM have pushed moisture a little
further into AZ for today. This moisture will again aid convective
development this afternoon and a few isolated storms had already
developed over predominant terrain features as of noon. Latest
mesoanalysis show an area of high SBCAPE (>1000 J/kg) across
portions of southeast AZ, that drops off quickly westward to 0
J/kg in the lower deserts of south-central AZ. With modest
instability over portions of southern Gila County a few convective
showers and storms may develop, with best chances over features
like Pinal Peak near Globe and the Hilltop area. Rainfall will be
very limited with any activity that develops, mostly less than
0.10". So, the greatest risks will be lightning generating new
fires and strong gusty outflow winds. The 12Z HREF and REFS runs
show around a 60-70% odds of thunderstorm wind gusts >35 mph in
southern Gila County. Decaying outflows may eventually make there
way toward the lower deserts later this evening with locally gusty
winds. The convective activity today will be diurnally driven and
should dissipate with the loss of heating. There will be a chance
for convection again tomorrow afternoon, but hi-res models are
showing less instability tomorrow and overall less coverage.

&&

.LONG TERM /Saturday through Tuesday/...
As we head into the weekend, ensembles point towards another trough
moving over western portions of the CONUS, which will eventually
become more amplified and stretch from British Columbia down the
California coast. However, uncertainty remains regarding the
strength and positions of this potential disturbance. The increasing
temperature spread through the weekend and into the start of next
week between the NBM 25th and 75th percentile reflects this
uncertainty. Nonetheless, even with the cooler air associated with
this potential system, it appears widespread triple digits are here
to stay. Regardless of which ensemble solution comes to fruition,
the continuation of breezy, to perhaps locally windy conditions
appears likely. The main question will be how strong gusts may
become, which will be dependent on how tight the regional pressure
gradient becomes. With little moisture flux, any breeziness will
keep the fire weather risk elevated at least through Sunday.

Forecast confidence does not improve for the start of next week as
model clusters show a wide variety of outcomes, with some showing
continued troughing, while others favor the return of high pressure.
The return of ridging across the western CONUS appear to be most
likely outcome at this time, but how amplified this feature becomes,
its placement, and if we remain under some influence of a lingering
area of low pressure remains uncertain at this time. One thing that
does appear certain though, other than our high terrain rain chances
today and Thursday, dry conditions are likely to prevail over the
next week at least for most of the region.

&&

.AVIATION...Updated at 1725Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT; and
Southeast California/Southwest Arizona including KIPL and KBLH:

No significant weather issues will exist through Thursday evening
under passing cirrus decks and a few afternoon CU/CB developing
over the mountains east of Phoenix. Confidence is very good that
trends in wind speeds and timing of directional shifts will be
very similar to the past 24 hours. However, the late
evening/overnight shift back to an easterly direction around the
Phoenix metro may occur a few hours earlier than the past couple
days due to decaying outflow descending into the valley from
storms over mountains.

&&

.FIRE WEATHER...
The threat for a isolated dry thunderstorms over southern Gila
County today and Thursday is the main fire weather hazard over the
next few days. Winds will follow typical diurnal tendencies with
typical afternoon upslope breeziness the next couple of afternoons.
Gusts begin to pick up Friday and into the weekend, mainly across
the Lower Colorado River Valley and high terrain areas of the
eastern districts. With daily MinRHs hovering close to 5-10%, even
marginal breezes will result in periods of elevated fire weather
conditions. Isolated instances of near critical to critical
conditions cannot be ruled out. Overnight recovery will offer very
little in terms of relief as MaxRHs run between only 15-45% for most
areas. Breezy, to locally windy, conditions are likely to continue
into the weekend, potentially lingering into the start of next week,
resulting in a prolonged period of daily occurrences of elevated to
near critical fire weather conditions starting on Friday.

&&

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

$$

SHORT TERM...Benedict
LONG TERM...RW
AVIATION...95/18
FIRE WEATHER...RW

NWS PSR Office Area Forecast Discussion