441
FXUS65 KPSR 241151
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
451 AM MST Fri May 24 2024

.UPDATE...
12Z Aviation Discussion.

&&

.SYNOPSIS...
A weak disturbance will pass over the region this weekend leading to
breezy to locally windy conditions and cooler Saturday high
temperatures. The strongest winds are expected this evening over
portions of Southeastern California, and widespread breeziness can
be expected on Saturday. By Memorial Day, highs will have heated
back up to around the century mark and remain near to slightly above
normal through the work week.

&&

.DISCUSSION...
Current mid level wv imagery and streamline analysis shows a
positively tilted shortwave trough moving onshore along the Pacific
Coast. Ahead of this feature, mostly zonal flow remains over the
Desert Southwest this morning. Heights will not begin to fall until
late today, so high temperatures this afternoon will reach similar
values to those observed yesterday in the mid to upper 90s across
the lower deserts. As the shortwave trough traverses the Great Basin
on Saturday, highs will be notably cooler at between 5-10 degrees
below normal for this time of year in the upper 80s to low 90s.

Widespread breezy to locally windy conditions will accompany the
aforementioned shortwave as it traverses the Great Basin this
weekend. This evening, winds will pick up primarily over portions of
Southeastern California such as JTNP and Southwestern Imperial
County including the Imperial Valley. Gusts are expected to peak
between 35-45 mph in these areas, with gusts up to 55 mph in the far
Southwestern corner of Imperial County along high terrain. Wind
Advisories have been issued for portions of Imperial County for late
this afternoon through this evening. Confidence in winds reaching
Advisory criteria in JTNP and locations further east in Imperial
County is low at this time, though HREF mean gusts are upwards of 35
mph in some of these areas this evening. Elsewhere across the lower
deserts, gusts will peak in the 20-30 mph range today. On Saturday,
afternoon breeziness will be widespread and South-Central AZ high
terrain will see peak gusts around 30 mph as the trough axis passes
overhead and quickly ejects east northeastward.

In the wake of the shortwave disturbance, heights will begin to rise
on Sunday and a ridging pattern will set up over the western CONUS
by Memorial Day. Global ensembles are in good agreement that this
ridging pattern will persist through much of next week, with some
slight discrepancies in strength/position of the ridge apparent in
the WPC cluster analysis. Temperatures into the middle 90s can be
expected by Sunday, rising further into the upper 90s to around 100
degrees for some areas by Monday. Day-to-day temperatures will
continue to increase through the middle of next week as the ridge
continues to dominate our forecast area. Afternoon highs by Tuesday
across the lower deserts are forecasted to range between 100-105
degrees, with similar conditions expected again on Wednesday. This
pattern will also promote tranquil and very dry conditions, with no
rain chances anticipated potentially through the end of May.

&&

.AVIATION...Updated at 1150Z.

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

VFR conditions are anticipated through the forecast period.
Easterly flow will prevail this morning with speeds remaining
aob 7 kts. There will likely be a 3-4 hr period of southerly
crosswinds (170v200) at KPHX late this morning before winds
ultimately shift out of the WSW by 20Z-21Z. Intermittent gusts
up to 20-25 kts can be expected this afternoon through early this
evening. Despite a few passing high clouds, skies should remain
mostly clear.

Southeast California/Southwest Arizona including KIPL and KBLH:

The main aviation concerns will be strong, gusty winds developing
at both terminals this afternoon and early evening. Westerly flow
will become established at KIPL late this morning while winds
remain southerly at KBLH. Gusts around 25-30 kts will become
common at both terminals by this afternoon. Stronger sundowner
winds are anticipated at KIPL after 00Z with gusts increasing to
around 35 kts at at times. Some of the stronger gusts may generate
dust channels, which could lead to temporary slantwise and surface
visibility reductions. FEW-SCT passing high clouds will move over
the region throughout the period.

&&

.FIRE WEATHER...
Elevated fire weather conditions will exist today and Saturday over
parts of the western districts and high terrain of the eastern
districts as a weak system helps to generate breezy to locally windy
conditions. Strongest winds (35-45 mph peak gusts) will be focused
over the western districts and enhanced terrain areas, with 20-30
mph gusts expected elsewhere. MinRH values during this timeframe
will increase slightly from 10-15% today, to 10-20% Saturday.
Overnight recoveries will be fair tonight and Saturday night at
around 30-50% and locally higher in high terrain locations. Hot and
dry conditions will persist beyond Saturday, with generally lighter
winds speeds and typical afternoon breeziness each day. Daily highs
will reach the century mark in many lower desert locations by Monday
and values generally top out between 100-105 through the middle
of next week.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...Wind Advisory from 4 PM this afternoon to 9 AM PDT Saturday for
     CAZ562.

     Wind Advisory from 4 PM this afternoon to 11 PM PDT this evening
     for CAZ563-566-567.

&&

$$

DISCUSSION...Whittock
AVIATION...Salerno
FIRE WEATHER...Whittock/RW