Tempe, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

030
FXUS65 KPSR 221139
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
439 AM MST Thu May 22 2025

.KEY MESSAGES...

1) Tripple digit high temperatures across the lower deserts continue
today and tomorrow, with today being the hottest day with highs
of 102-107 degrees.

2) These hot temperatures will result in widespread Moderate
HeatRisk (Level 2) today and localized Moderate HeatRisk tomorrow,
posing an increased risk to vulnerable populations.

3) Afternoon breeziness is expected today through Saturday, with
the strongest winds on Friday resulting in locally elevated fire
weather conditions.

&&

.DISCUSSION...

Weather Pattern Overview:

Mid-level water vapor imagery and objective analysis this morning
show quasi-zonal flow overhead, with RAP analyzed H5 heights around
584-586 dm. As of early this morning, we are already a couple
degrees warmer than we were at the same time yesterday and with H5
heights expected to rise slightly this afternoon high temperatures
are forecasted to be a couple degrees warmer than yesterday. Lower
desert high temperatures are forecasted to be in the 102-107
degree range, with higher terrain areas to be in the mid 90s to
near 100 degrees. These temperatures will be around 8-10 degrees
above the normal/average for this time of year, but will still be
3-5 degrees shy of record highs. With these hot temperatures
there will be widespread Moderate HeatRisk across the lower
deserts, with some even expanding into the higher terrain areas.
So, make sure to practice smart heat safety and try to limit your
time outdoors and drink plenty of water.

H5 heights will fall slightly tomorrow ahead of a weak shortwave
trough that will move onshore late tomorrow night. This will cause
temperatures to slightly decrease, with lower desert high
temperatures forecasted to be 100-104 degrees tomorrow. The
shortwave trough will continue to make its way inland and through
our areas over the weekend. As the trough moves into our area it
will cool temperatures down even more, with afternoon high
temperatures falling into the mid-to-upper 90s across the lower
deserts on Saturday. In addition to slightly cooler temperatures, it
will also cause the pressure gradient to tighten leading to an
increase in winds. Friday will be the breeziest day, with afternoon
and evening wind gusts of 15-25 mph across most of the region and 30-
35 mph gusts in southeastern California. Some residual breeziness is
expected Saturday afternoon.

By the end of the weekend and heading into next week the upper level
flow pattern will become fairly stagnant, with positive height
anomalies over Canada and negative height anomalies over the Gulf of
Alaska. Global ensembles continue to show this pattern holding
throughout the week, with the potential of another shortwave trough
moving through our region in the middle of next week. Ensembles show
slight ridging overhead by the beginning of the week allowing lower
desert high temperatures to rise a few degrees and getting back
into the upper 90s to low 100s. With the aforementioned shortwave
expected to move through the region during the middle of the week,
that will help to keep temperatures steady, rather than
increasing. While ensembles continue to slightly disagree on the
exact strength and timing of the shortwave trough, dry conditions
will continue through next week with temperatures remaining
slightly above normal.

Forecast Confidence & Deviations:

In keeping consistent with the previous forecast package, have
increased winds over Imperial County on Friday evening by around
15%. Otherwise, no other edits were made to the NBM grids. Forecast
confidence is good through the weekend but decreases gradually
heading into next week.

&&

.AVIATION...Updated at 1140Z.

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

No major weather issues will exist through tonight under clear
skies. The only issue will be KBLH at times (during the overnight
and morning hours) seeing some restriction in VIS due to a nearby
wildfire. Otherwise, trends in wind speeds and timing of typical
wind shifts will be similar to the past 24 hours. Periods of
variability and nearly calm conditions during these transitional
periods will be common.


&&

.FIRE WEATHER...
High pressure will continue to dominate today, with afternoon high
temperatures of 102-107 degrees across the lower deserts and in the
mid 90s to near 100 degrees in the higher terrain. Temperatures
will cool a couple degrees tomorrow and even further on Saturday
(lower desert highs in the mid to upper 90s). Very dry conditions,
with min RHs of 5-12%, will continue into next week. Daily
afternoon and evening breezy to locally windy conditions will
exist today-Saturday, leading to elevated fire weather conditions.
The highest winds are expected tomorrow with gusts of 20-30 mph
across most of the region and gusts up to 35 mph across
southeastern California.

&&

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

$$

DISCUSSION...Berislavich
AVIATION...Kuhlman
FIRE WEATHER...Berislavich