460
FXUS65 KPSR 090534
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1034 PM MST Sat Jun 8 2024

.UPDATE...
06z Aviation Discussion.

&&

.SYNOPSIS...
Slightly cooler, although above normal, temperatures are forecast
through the weekend into Monday. Expect temperatures to heat up
by the middle of next week due in large part to high pressure
building into the region. Dry conditions will prevail through the
forecast period.

&&

.DISCUSSION...
For the short term, weak circulation associated with a very weak
upper-level low located over the Sonoran Desert region of the
northwest corner of Mexico continues to gradually move northward
into AZ helping to slightly lower 500 mb heights dropping temps a
couple of degrees. Expect low temperatures this evening to dip to
the low 80s for the Phoenix Metro and low to mid 70s for the
surrounding region. Expect low temps to fall to the upper 60s in
higher mountain elevations. Along with the cooler temperatures,
the weak upper-level low will also help enhance somewhat the early
evening breeziness across the area, with the potential for some
gusts exceeding 30 mph at times across portions of western
Imperial County. Upper level clouds will continue to build into
the eastern portions of the CWA this evening, slightly clearing
overnight, building back in tomorrow during the day. Winds will
continue to generally favor diurnal tendencies with occasional
afternoon gusts of 20-25 mph expected across most of the region
tomorrow.

Heading into next week, model guidance continues to remain in
pretty good agreement in the overall synoptic pattern as another
upper-level low is set to cutoff off the coast of southern
CA/northern Baja by Monday with a ridge strengthening across the
southwestern CONUS. There still continues to be some discrepancies
examining the ensemble cluster analysis in the overall
positioning/strength of the cutoff low, which will dictate the
positioning of the ridge downstream. Latest trend indicates a
pretty robust ridge building across NM/AZ by midweek with 500 mb
height fields rising above 590dm across most of the region with
values as high as 594-597dm across the eastern half of AZ through
NM. Therefore, an uptick in temperatures can be expected heading
into the Tuesday-Thursday timeframe with another round of
excessive heat conditions possible, especially across the south-
central AZ lower deserts, as highs will likely once again reach
110+ degrees and potentially necessitating the issuance of new
excessive heat products.

Ensemble and cluster analysis shows a cutoff low eventually
making its way through the region by the end of next week,
bringing slightly cooler temperatures. Heading into next weekend,
a more potent large-scale trough will approach the Pacific
Northwest and traverse the western CONUS. However, there is a
large degree of spread amongst the ensembles and large
uncertainty in cluster analysis on the overall depth and position
of the trough, which will dictate whether or not the Desert
Southwest will see any impacts in the form increased winds,
further cooling, and potential precipitation.

&&

.AVIATION...Updated at 0530Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT;
No aviation weather concerns are anticipated through the forecast
period. Winds will follow typical diurnal patterns with easterly
flow become reestablished by 07Z at KIWA and 09Z at KPHX. Speeds
should remain aob 8 kts overnight. There will be a period of S-SE
crosswinds at KPHX tomorrow morning through early tomorrow
afternoon before winds finally shift out of the SW by 21Z-22Z.
High clouds will remain FEW-SCT at 20-25 kft over the region
through tomorrow afternoon.

Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation weather concerns will exist through the TAF period.
Winds will continue to favor a southerly component at KBLH with
speeds remaining around 10-11 kts. Gusts up to 20 kts will be
possible at KBLH by tomorrow afternoon. At KIPL, gusty westerly
winds will subside over the next few hrs and are expected to shift
out of the southeast after sunrise tomorrow morning. Skies will
remain mostly clear over southeast CA with the exception of a few
passing high clouds.

&&

.FIRE WEATHER...
Hot and seasonably dry conditions will continue to support a high
fire danger across the area into late next week. Slightly cooler
temperatures, although still remaining above normal, can be
expected through Sunday before heating up once again heading into
the middle of next week. Winds will continue to generally favor
diurnal tendencies with occasional afternoon breeziness of 20-25
mph expected across most of the region. MinRHs ranging between
5-15% with poor to fair overnight recoveries of between 20-45%
will be common.

&&

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

$$

DISCUSSION...95/Lojero
AVIATION...Salerno
FIRE WEATHER...95/Lojero