353
FXUS65 KPSR 300548
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1035 PM MST Wed May 29 2024

.UPDATE...
Updated Aviation

&&

.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 remain several degrees above
normal with readings between 100 and 106 degrees under sunny to
mostly sunny skies.

&&

.DISCUSSION...
The hot, dry, and tranquil weather pattern persists across the
Southwest as dry zonal flow prevails with upper ridging now shifting
east across the central CONUS. This pattern will continue to promote
abundant sunshine across the region with current visible satellite
imagery this afternoon only showing a few passing high clouds across
the state. Ensemble guidance indicate 500 mb heights will remain
steady around 583-585 dm through the remainder of this week and into
the start of next week. This will keep afternoon temperatures each
day several degrees above normal as lower desert highs top out in
the 100-106 degree range for most places. With these temperatures
will come widespread Minor and pockets of Moderate HeatRisk, so the
necessary heat safety precautions should be exercised. Given the
current pattern, winds each day will overall remain light outside of
periodic afternoon wind gusts to around 20 mph. A weak shortwave
pushing through the Southwest this weekend may slightly enhance
winds and also lead to a degree or two dip in temperatures.

Going into the middle part of next week, uncertainty increases as
ensemble and deterministic models depict a cutoff low setting up off
the coast of southern California and the Baja Peninsula while strong
ridging builds across the western CONUS. Ensemble cluster analysis
shows good agreement in regards to ridging building/strengthening
over the western CONUS, but the strength and position of the cutoff
low is uncertain. At this point, little in the way of sensible
impacts is expected from the cutoff low with the greater impacts
coming from the aforementioned ridge. Global ensembles indicate the
ridge pushing average 500 mb heights to around 590 dm, which would
translate to temperatures climbing well above normal. NBM
temperature forecast spread increases mid/late next given some of
the aforementioned uncertainty, but overall temperature trends
increase closer to 110 degrees. The average (1991-2020) first
occurrence of 110 degrees in Phoenix and Yuma is June 11th and for
El Centro is June 14th, so the first occurrence would be slightly
earlier than normal if temperatures were to reach 110 degrees in
these places next week.

&&

.AVIATION...Updated at 0535Z.

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

No significant weather issues will exist through Thursday night
under clear skies. Wind trends at the Phoenix area terminals will be
nearly identical to the past 24 hours favoring west winds during
the afternoon and evening hours with the traditional overnight/early
morning easterly component. Across SE California, a west wind
be preferred at KIPL, while south winds should be more common at
KBLH. Periods of light and variable winds will be typical across the
entire region at times.

&&

.FIRE WEATHER...
Hot and dry conditions will prevail through the remainder of this
week with daily highs remaining above normal. Overall light winds
will follow diurnal tendencies each day with afternoon gusts in the
mid-teens to around 20 mph. MinRH values will range between 5-10%
each afternoon while overnight Max RHs range between 20-40% for most
places.

&&

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

&&

$$

DISCUSSION...Smith
AVIATION...18
FIRE WEATHER...Smith/Kuhlman