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776
FXUS65 KPSR 231138
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
438 AM MST Thu May 23 2024

.UPDATE...
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Updated Aviation Discussion.
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&&

.SYNOPSIS...
Clear to mostly clear skies and dry conditions will prevail
through the holiday weekend with temperatures close to normal
through the weekend before warming early next week. The coolest
day should be Saturday with lower desert highs mostly in the
upper 80s with other days seeing readings mostly in the mid 90s.
Temperatures should then warm up to around 100 degrees by Memorial
Day and potentially as warm as 105 degrees by the middle of next
week.

&&

.DISCUSSION...
The synoptic pattern continues to support progressive weather
systems generally tracking across the northern half of U.S. with
the broad troughing extending as far south as the Desert
Southwest. Current water vapor imagery shows one weather system
tracking east southeastward across Idaho and northern Utah, while
another less organized disturbance is seen moving southeastward
off the coast of northern California. The system to our north will
have no impact on our region as we remain under a dry westerly
flow today and highs once again mainly top out in the mid 90s
across the lower deserts.

By Friday, the disturbance off the coast of California is forecast
to strengthen slightly as it comes ashore across southern
California in the afternoon before moving through Arizona Friday
night. The main impact with Friday`s weather system will be the
increase in winds across the region with afternoon and evening
winds commonly gusting to between 20-25 mph across southern
Arizona to as high as 30-40 mph across portions of southeast
California. Heights aloft are also expected to drop enough with
the passage of the dry weather system to bring a noticeable drop
in temperatures as highs on Saturday are expected to mostly top
out in the upper 80s to around 90 degrees, or 6-8 degrees below
normal.

The larger scale pattern is then forecast to shift later over the
weekend into early next week with a ridge building over the
Western U.S. This should quickly boost H5 heights from around
574-578dm on Saturday to around 584dm Monday before peaking at
around 586dm during the middle part of next week. Dry conditions
will persist as the upper level ridge dominates across the region
during at least the first half of next week, while a weaker
gradient should keep winds from being very breezy. Lower desert
high temperatures will quickly rise to a few degrees above normal
starting Memorial Day to as warm as 102-106 degrees by around next
Tuesday and/or Wednesday. With normal highs still rising fairly
quickly during the last week of May, even highs of around 105
degrees would only be 5-7 degrees above normal.

&&

.AVIATION...
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Updated at 1138Z.

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

Typical diurnal wind tendencies will persist at all terminals
through the next 24 hours. E winds this morning will veer
gradually W/SW by 21-22Z, with a period of southerly variability
between 16-21Z. Breezes increase up to 8-12 kts, with gusts up to
20 kts, with the W/SW shift. A gulf surge in the evening will keep
winds W/SW through 6-8Z before diurnal E winds set in. SKC will
prevail through this afternoon followed by SCT cirrus tonight.

Southeast California/Southwest Arizona including KIPL and KBLH:

S/SW winds will prevail at KBLH and W/SW will prevail at KIPL.
Although, there will also be periods of variability and there is
some uncertainty in the wind directions at KIPL during the day as
a light SE wind may develop as early as 15-16Z. Speeds increase
up to 10-15 kts at KBLH this afternoon, while KIPL increases up to
12-18 kts this evening. Both terminals will see gusts up to
around 25 kts. SKC will prevail, followed by SCT cirrus this
evening.
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&&

.FIRE WEATHER...
Dry and tranquil conditions will continue through the next few
days, with temperatures hovering right around normal for this time
of year. Winds will follow typical diurnal trends with occasional
afternoon gusts around 20 mph today before increasing on Friday
with gusts commonly reaching 25 mph over the eastern districts to
up to 35 mph across southeast CA. MinRH values will range between
8-15% through Friday before improving to 10-20% Saturday, while
MaxRHs improve from 25-40% today to 35-50% by Saturday. High
pressure is then expected to impact the region Sunday through the
first half of next week bringing strong warming and above normal
temperatures, while MinRHs drop back into the single digits.
Overall light winds are also expected starting Sunday.

&&

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

$$

DISCUSSION...Kuhlman
AVIATION...Benedict
FIRE WEATHER...Kuhlman