Chiriaco Summit, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

592
FXUS65 KPSR 072007
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
105 PM MST Sat Jun 7 2025

.DISCUSSION...

KEY MESSAGES:

- Dry conditions through the period with temperatures peaking
upwards of 10 degrees above normal early next week

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

Early afternoon WV imagery shows the formative stages of Rex
blocking across western North America with high amplitude ridging
extending into northern British Columbia while the trapped cutoff
low spins aimlessly off the central California coast. Concurrently,
subtropical high pressure has been strengthening over S Texas/N
Mexico with retrogressive tendencies battling against the basal,
westerly flow of the upstream block. These features will essentially
stall over the next 48 with currently analyzed H5 heights in a 586-
590dm range remaining nearly constant over the next 48 hours.
Intense June insolation will steadily warm the lower troposphere
such that surface readings fall just outside a persistence forecast,
and forecast confidence is excellent that temperatures will peak 5F-
10F above normal the next several days. NBM forecasts remain
consistent in advertising the warmest readings across SE California
where odds of hitting 110F remain well above 50% for many lower
elevation communities, while odds around most of the Phoenix metro
hover below 50%.

During the latter half of next week, the hemispheric flow pattern
will attempt to become more progressive with western Conus blocking
deamplifying and relaxing and strong Pacific jet energy carving out
mean longwave troughing over the NE Pacific basin. Ensemble suites
remain very uncertain with respect to the depth and orientation of
negative height anomalies off the Pacific NW coast, as well as the
interaction with the nearly stationary downstream subtropical ridge.
A growing contingent of GEFS members are less pronounced with the
depth and proximity of this trough to the Great Basin, and as a
result, suggest the subtropical anti-cyclone center more intense and
closer to the CWA with H5 heights only marginally dipping below
588dm. Several CMC and EC members also seem to be trending in this
direction, though the number of members not as prolific as the GEFS
collection. While some very minor cooling still appears likely late
in the week, not surprisingly, mandated NBM forecasts have decreased
the amount of cooling several degrees with readings solidly remain
above the seasonal normal. Though outside the time frame of this
forecast package, there is mounting evidence of 595dm (or greater)
H5 heights developing somewhere in the region next weekend -
possibly overhead, but more likely towards New Mexico or the four
corners. This scenario could yield the first bout of extreme heat
for parts of the forecast area during the middle of the month.

&&

.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...
Above normal temperatures will be common through much of next week
with the warmest period early in the week. Recent moisture
availability has largely been scoured from the districts with
minimum afternoon RHs will falling near 10% (more prevalent single
digit RH`s occurring tomorrow and Monday). This will be accompanied
by poor to fair 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...18
AVIATION...Smith/Young
FIRE WEATHER...Ryan/18