Wind Advisory 28, NWS Phoenix, AZ

Area Forecast Discussion
National Weather Service Phoenix AZ
1057 PM MST Thu May 26 2022

.UPDATE...Update Aviation Discussion.

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.SYNOPSIS...
High pressure will strengthen over the region today into Friday
while high temperatures warm to around 105 degrees for a good
portion of the lower deserts. Over the weekend, a rather
noticeable cooldown is expected, pushing high temperatures to
below 100 degrees by Sunday, then well down into the 90`s early
next week. Along with the cooler temperatures, gusty winds and
high fire danger levels can be expected. Dry conditions and mostly
clear skies will prevail through next week.

&&

.DISCUSSION...
The ridge of high pressure has now fully moved over our region
with clear skies prevailing region wide. The warming trend will
continue today as heights aloft peak tonight into early Friday.
Widespread lower desert highs of 103-106 degrees are still
forecast for today and Friday, resulting in moderate heat risk but
falling well short of any daily records (given the fact that ENS
Standardized Anomalies only reach +1.6 SD above climo late
tonight…which are rather modest values). Fortunately, this boost
in temperatures will be short-lived as a large upper level trough
currently approaching the Pacific Northwest begins to move into
the Western U.S. starting tonight. By Saturday, latest ensemble
guidance still shows the center of the trough moving over the
Pacific Northwest with the base of the trough extending as far
south as northern Arizona.

After the very warm temperatures today and Friday, the main
forecast concern then shifts toward an increase in winds beginning
Saturday and continuing into Sunday. As the trough approaches our
region from the northwest on Saturday, rapid height falls and an
increasing pressure gradient over our region will result in a
return of widespread breezy to windy conditions. The strongest
winds Saturday will be focused more across southeast California
and across the Arizona high country where latest EFS ensemble
guidance and NBM output is indicating that advisory level winds
will be likely, mainly over SW Imperial County and the Imperial
Valley. The focus for the strongest winds on Sunday moves over
South-Central AZ as the center of the trough enters the Great
Basin, increasing the gradient further over our region. Guidance
is now suggesting winds easily gusting to 25-30 mph across the
lower deserts of South- Central AZ on Sunday afternoon, with gusts
up into the 35-45 mph range over the higher terrain areas north
and east of Phoenix. Temperature are still expected to take a dive
during the Sun-Tue period as cooler air moves into the region as
500 mb height anomalies fall into the -1.0 to -1.5 SD range below
climo and 850mb temp anomalies fall into the -2.0 to -2.5 SD range
below climo. This will likely result in lower desert highs
falling to the mid-90’s across SE CA/SW AZ and the lower 90’s
across South-Central AZ. These well-below normal highs combined
with lows in the very pleasant upper 50’s to upper 60’s (and a
very dry airmass) will mean a very nice break in the heat for
this time of year!

With model ensembles still mostly favoring the trough exiting
well to the northeast of the region by next Wednesday,
temperatures should warm back to or even a few degrees above
normal during the latter half of next week, but for now highs are
shown to most likely max out at around 105 degrees at some point
late next week before trending slightly lower again into the
following weekend.

&&

.AVIATION...Updated at 0555Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Starting off with mostly light W winds with the latest guidance
advocating a switch to the E around 09Z, along with mostly light
windspeeds. A late morning switch to the SW on Fri with occasional
gusts into the teens by mid to late afternoon and into the
evening. Clear to mostly clear skies into Fri morning with
increasing high clouds by midday Fri and becoming partly to
occasionally mostly cloudy with SCT v BKN high clouds by Fri
night and into Sat morning.

Southeast California/Southwest Arizona including KIPL and KBLH:
Elevated W-NW winds AOB 11 kt tonight at KIPL. Lighter winds by
early Fri will then favor a normal diurnal pattern followed by a
mid afternoon switch to the SW on Fri. Then gusty sundowner winds
with W gusts upwards of 25 kt expected by very late Fri afternoon.
At KBLH, winds continue to favor a S component. Mostly light S
winds will go light and variable later tonight. Elevated S flow
resumes mid morning Fri with stronger gusts upwards of 20 kt
beginning by early to mid afternoon and remaining elevated into
the night. Mostly clear skies are expected to persist before
increasing SCT high clouds move in Fri.

&&

.FIRE WEATHER...
Strong high pressure over the region will result in above normal
temperatures over the next few days with highs above 100 degrees
across the lower deserts. Afternoon MinRHs will range between
6-12% through Saturday, while overnight MaxRHs recover to between
20-35% across most areas. Relatively light winds can be expected
through Friday, however, some periodic afternoon gusts into the
teens are likely. Another (rather strong for this time of year)
weather disturbance moving across the western states over the
weekend into early next week will bring widespread windy
conditions Saturday and Sunday with wind gusts commonly in a 25-30
mph range, locally higher across the western deserts and the
Arizona high terrain. Although RHs will improve slightly by Sunday
as temperatures drop below 100 degrees, the increased winds and
continued dry conditions are likely to result in high fire danger
levels this weekend. Fire danger levels will likely approach
criteria thresholds over the higher terrain to the north and east
of Phoenix on Sunday. Lighter winds, warmer temperatures and
lower fire danger levels can be expected early next week as high
pressure begins to build back over the region.

&&

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

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DISCUSSION...Percha/Kuhlman
AVIATION...Sawtelle
FIRE WEATHER...Percha/Kuhlman