San Tan Valley, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

130
FXUS65 KPSR 071700
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1000 AM MST Sat Jun 7 2025

.UPDATE...Updated Aviation Discussion.

&&

.DISCUSSION...

KEY MESSAGES:

- Dry conditions with temperatures peaking around 10 degrees above
normal early next week

- Widespread moderate HeatRisk during the first half of next week
relaxing later in the week

WV imagery continues to show a swath of dry air infiltrating into
the region from a long wave trough off the Southern CA coast. This
is drying the region as we will see surface dew points in the low to
mid 30`s across most of the Desert SW, and below normal PWAT values.
Accompanying the dry air, subtropical ridging, seen in northern
Mexico, has been slowly retrograding towards the west building high
pressure aloft over the Desert SW in a temporary rex block pattern.
These together will facilitate warming and drying conditions
reflected in forecasted temperatures especially for this weekend and
the early half of next week.

Though the subtropical ridge will not sufficiently build directly
over the region as it retrogrades, it will however help increase the
500mb heights over the region as it does so over the next several
days. Today peak 500mb heights across the lower Deserts will be near
585-589 dm with high temperatures expected to near 104-106 degrees
across the lower Deserts. By Sunday, and lingering into the middle
of next week, temperatures will increase a few degrees from today,
with 500mb heights peaking near 588-591 dm. This will lead to high
temperatures ranging between 105-110 degrees in the lower deserts,
with Monday expected to be hottest day. Temperatures will be
slightly higher in SE California, and along the Colorado River
Valley with NBM probabilities of reaching 110 or above between 50-
80%, while in the Phoenix Metro the chances of 110 or above are near
30-60%.

By late next week ensemble models suggest the formation of a trough
in the Pacific NW, that looks to deepen across Western CONUS. There
is uncertainty in how amplified this troughing feature will develop,
but still looks to lower mid level heights, resulting in
temperatures returning to near normal by late next week across the
region. This is supported in the NBM interquartile temperature
ranges with high temperatures on Friday ranging between 100-105, and
the deterministic nearing normal for this time of year in the lower
Deserts. However this looks to be a brief relief as subtropical
ridging begins to build back into the region.

&&

.AVIATION...Updated at 1700Z.

South Central Arizona including KPHX, KIWA, KSDL, KDVT:
No aviation weather concerns are expected through the TAF period
under clear skies. The overall wind pattern will continue to
exhibit the typical diurnal tendency with speeds aob 10 kts.
Periods of light and variable winds are likely as well during the
transition periods.

Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation weather concerns under clear skies are expected
throughout the TAF period. Winds at KIPL will fluctuate between
the east to southeast through this afternoon before shifting out
of the west for a period during the evening and into the overnight
hours. Winds at KBLH will fluctuate between the southeast and
southwest. Overall wind speeds will remain aob 10 kts. Periods of
light and variable winds are likely as well.

&&

.FIRE WEATHER...
Warming temperatures with highs climbing near 10F above normal
will affect the region through the middle of next week while the
environment becomes progressively drier. Afternoon MinRHs will
largely fall near 10% with more prevalent single digit RH`s
tomorrow and Monday. This will be accompanied with poor to
progressively fairer overnight recovery of 20-40%. Winds should
follow fairly typical late spring cycles with periods afternoon
upslope gustiness. Somewhat more breezy conditions may arrive to
the region towards the end of next week resulting in a slightly
elevated fire danger.

&&

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

$$

DISCUSSION...Ryan
AVIATION...Smith/Young
FIRE WEATHER...Ryan/18