946
FXUS65 KPSR 291131
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
431 AM MST Wed May 29 2024

.UPDATE...Updated 12z Aviation Discussion.

&&

.SYNOPSIS...
Dry and tranquil weather conditions will persist through at least
the weekend, but expect continued above normal temperatures as
high pressure generally dominates across the region. High
temperatures each day across the lower deserts will run around
five degrees above normal with readings between 100 and 105
degrees under sunny to mostly sunny skies.

&&

.DISCUSSION...
The weather pattern through the weekend will keep dry zonal
westerly flow over the Desert Southwest with influences from the
sub-tropical ridge which will remain positioned to our south.
This will result in H5 heights remaining fairly stable at between
582-585dm, still within the normal range for this time of year,
but high enough to keep temperatures around five degrees above
normal. Lower desert forecast highs are mostly between 100-105
degrees through around next Monday or Tuesday before higher model
spread is seen in the NBM. Overall weak flow across the region
will keep daily winds fairly light with periodic afternoon wind
gusts around 20 mph.

Model uncertainty increases by the middle of next week leading to
lower forecast confidence as ensemble guidance indicates a
potential weak cut-off low developing somewhere off the coast of
southern California or northern Baja. At the same time, a stronger
upper level ridge is likely to push its way inland over the Great
Basin while the sub-tropical ridge over Mexico strengthens and
likely pushes northward into Texas and New Mexico. So far
ensemble guidance overall agrees with the ridging strengthening
over much of the Western U.S. later next week, but the cut-off
low`s position and strength is highly uncertain. Even if the low
is close to our region, it will likely have little influence on
our overall sensible weather as any quality moisture should stay
well east of Arizona. NBM forecast temperature spread increases a
good deal by the middle of next week, but the overall temperature
range still trends upward through the rest of the week as mean H5
heights are favored to push closer to 590dm. So far it looks very
possible some lower deserts may be flirting with 110 degrees at
some point late next week.

&&

.AVIATION...Updated at 1130Z.

South-Central Arizona including KPHX, KIWA, KSDL, KDVT:

Winds will follow their typical diurnal patterns with some
extended periods of light and variable winds. Wind speeds will
generally be aob 10 kt through the TAF period, however, some
periodic gusts into the teens will be possible once again this
afternoon. Mostly clear skies will prevail, though FEW-SCT high
clouds developing over the next several hours cannot be ruled out.

Southeast California/Southwest Arizona including KIPL and KBLH:

At KIPL, winds will mainly be out of the west through the TAF
period whereas at KBLH winds will be out of the south to
southwest. Gusts into the mid 20s are expected to develop again
this evening at KIPL. At KBLH, wind speeds will be aob 10 kt
sustained through the TAF period, with the potential for
occasional gusts into the mid to upper teens this afternoon. Clear
skies will prevail.

&&

.FIRE WEATHER...
Hot and dry conditions will persist into next week with daily
highs around 5 degrees above normal. MinRH values will remain at
or below 10% across the lower deserts and overnight recoveries
will commonly be poor at around 20-40%. Winds through the period
are generally expected to remain fairly light, but daytime
breeziness with gusts around 20 mph can be expected.

&&

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

$$

DISCUSSION...Kuhlman
AVIATION...Whittock/Berislavich
FIRE WEATHER...Kuhlman