-- Discussion containing changed information from previous version are highlighted. --
052
FXUS65 KPSR 230522
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1022 PM MST Wed May 22 2024

.UPDATE...
Updated Aviation section.

&&

.SYNOPSIS...
Temperatures will hover right around normal in the middle to upper
nineties over the next few days before an area of low-pressure
brushes by our region, resulting in a slight cool down for the
start of the weekend. Breezy conditions will accompany this low,
with the strongest gusts focused over parts of southeast
California on Friday. Dry conditions will prevail through at least
the middle of next week.

&&

.DISCUSSION...
Current atmospheric analysis reveals a similar setup compared to
yesterday, with weak troughing stretching across the Desert
Southwest. This pattern will persist through the end of this week,
with H5 heights hovering right around climatological normals for
this time of year. These consistent heights will result in a steady
temperature trend through Friday across much of our forecast area,
with temperatures ranging in the middle to upper 90s across the
lower deserts. The one exception to this trend will be over parts
of SE California on Friday. A more potent area of low pressure is
expected to develop over the Great Basin on Friday, which will
help lower regional heights aloft, with the greatest height falls
focused over California. Day-to-day temperatures, as a result,
will decrease slightly towards the lower and middle 90s across
Imperial and Riverside Counties. As this aforementioned low
traverses our forecast area through the end of the work-week and
into the start of the weekend, more widespread cooling will be
observed, with forecasted high temperatures for Saturday only
ranging in the upper 80s to low 90s across desert communities, a
good 5-10 degrees below normal for this time of year.

An enhancement in the regional pressure gradient can also be
expected as the aforementioned disturbance approaches the region,
resulting in widespread breezy to locally windy conditions, with
the strongest gusts focused over the typically breezy to windy
areas of Imperial and Riverside Counties Friday afternoon and
evening. Peak gusts of 35 mph will be common across these areas,
with a good chance (>80%) of winds exceeding advisory-level
criteria (>40 mph gusts) for areas around the Imperial Valley and
Salton Sea. Due to the enhanced wind potential, a Wind Advisory
may need to be posted for the previously mentioned areas for
Friday afternoon and evening. Areas around the Colorado River
Valley may also see gusts approach advisory levels. However, at
this time, the potential of seeing winds exceed this threshold is
too low to warrant consideration of a Wind Advisory for these
areas. Elsewhere across our forecast area, gusts 20-30 mph will be
common, with isolated higher gusts over higher terrain areas. The
NBM continues with breezy to locally windy conditions (peak gusts
30-35 mph) Saturday afternoon/evening, especially for SE
California and the high terrain of south-central Arizona. However,
some discrepancies remain amongst the models regarding how
enhanced the winds may become during the start of the weekend.
This disagreement largely revolves around how quickly the low
progresses, with a slower-moving system favoring relatively
stronger winds once again Saturday afternoon/evening.

Model clusters agree that once the above-mentioned system exits the
region, a quick warm-up will ensue as ridging builds over much of
the western CONUS during the latter portion of the Memorial Day
Weekend. Afternoon highs Sunday will rebound towards the middle
90s across the lower deserts, with upper 90s to around 100 degrees
expected by Monday. This warming trend will continue into
Tuesday, with widespread triple digits for the lower elevations,
with a few spots potentially reaching 105 degrees. Outside of the
enhanced breeziness Friday (and potentially Saturday) dry and
tranquil conditions will prevail through at least the middle of
next week, with no rain chances in the foreseeable future.

&&

.AVIATION...
-- Changed Discussion --
Updated at 0523Z.

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

Weak upper level troughing over the Desert Southwest will maintain
dry southwesterly flow aloft. In the lower troposphere and the
surface, familiar diurnal patterns continue with the downvalley
patterns underway early in the TAF period (gustiness at KIPL).
This will be followed by upvalley patterns (favoring SW/Wly
directions over Greater Phoenix) and breeziness (gusts to 20kts)
in the afternoon and early evening (gusts 25-30kts at KIPL and
KBLH). Expect clear skies apart from some very minor cirrus
Thursday evening.
-- End Changed Discussion --

&&

.FIRE WEATHER...
Dry conditions, near normal temperatures, and typical afternoon
and early evening breeziness will continue through Thursday. Winds
will tend to follow their typical diurnal tendencies and terrain
influences in all districts with periodic gusts up to around 20
mph in the afternoon and early evenings. A passing dry weather
system on Friday into Saturday is likely to bring an increase in
winds with gusts of 20-30 mph over a good portion of the area.
This could lead to areas of elevated fire weather conditions
mainly on Friday. MinRH values through the weekend will mostly
fall to between 8-15% each day with overnight MaxRHs mostly
between 25-40%. Temperatures over the weekend will be near to
slightly below normal before warming to above normal early next
week as stronger high pressure settles over the region.

&&

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

$$

DISCUSSION...RW
AVIATION...AJ
FIRE WEATHER...Kuhlman