604
FXUS65 KPSR 021156
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
456 AM MST Thu May 2 2024

.UPDATE...Updated 12z Aviation Discussion.

&&

.SYNOPSIS...
Above normal temperatures are anticipated through Saturday with
lower desert highs reaching the low to mid 90s each afternoon. A dry
weather system will pass through the Intermountain West this weekend
resulting in widespread breezy to locally windy conditions and
cooler temperatures on Sunday and Monday. Dry weather will continue
with steadily rebounding temperatures through early next week.

&&

.DISCUSSION...
The upper level pattern has not changed much over the past 24 hrs
as large scale troughing remains the predominant feature across
the western CONUS and dry westerly mid-lvl flow prevails over the
forecast area. Warm and dry weather will continue across the
Desert Southwest and winds will be light with the exception of a
few rogue afternoon gusts. Daily highs are expected to reach the
upper 80s to lower 90s or around 3-5 degrees above normal through
Saturday. Overnight lows across the region will continue to be
mild in the upper 50s to mid 60s.

As we head into this weekend, ensembles and deterministic forecast
models depict a cutoff low entering the Pacific NW on Saturday and
swinging across the Intermountain West on Sunday and Monday. There
seems to now be better agreement between the ensemble members
regarding the overall progression and strength of this feature with
both the EPS and GEFS showing the system deepening and propagating
through NV and UT on Sunday. The main impact from this system will
be gusty winds beginning out west across the Imperial Valley
Saturday evening. Latest NBM wind gusts have increased substantially
across SE California after 00Z Sunday where strong sun-downer winds
will be possible in Imperial County. NBM probabilities have increased
to 70-80% for gusts greater than 40 mph, especially in the Southwest
Corner of Imperial County through late Saturday night.

The base of the upper-lvl trough will reach N AZ on Sunday
afternoon. As this occurs, hghts aloft will decrease over the
forecast area resulting in cooler temperatures region-wide with
highs mainly in the mid to upper 80s. Widespread breezy to windy
conditions can be expected Sunday afternoon with gusts in the
30-35 mph range across the lower deserts of southcentral AZ and
40+ mph in the AZ high terrain. Longwave troughing will continue
to be reinforced over the Intermountain West through Monday which
will also feature near to slightly below normal temperatures and
continued breeziness across the region. Heading into the middle of
next week, temperatures look to slowly rebound to slightly above
normal, however the overall longwave troughing pattern across the
Western CONUS looks to persist.

&&

.AVIATION...Updated at 1150Z.

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

No major weather issues will exist through the TAF period under
clear skies. Wind directions will follow a similar pattern to that
of the last 24 hours, with west winds establishing by the early
afternoon across the South-Central Arizona terminals and a
southerly component favored at the Southeast California terminals
through much of the period. Intermittent periods of variability
are anticipated. Wind speeds will remain light (generally aob 10
kts sustained), though occasional gusts into the mid teens will
be possible through the afternoon and early evening hours.

&&

.FIRE WEATHER...
Warm and dry weather with light and diurnal winds will continue
through the remainder of this week. Afternoon highs will top out
around 3-5 degrees above normal through Saturday. A dry weather
system will pass north of the region on Sunday, resulting in
widespread breezy to windy conditions and slightly cooler
temperatures. Winds could gust as high as 40 mph in SE California
on Saturday evening and up to 30-40 mph across southcentral AZ on
Sunday. Afternoon min RHs will bottom out around 8-20% over the
next few days, while overnight recoveries remain in the poor to
fair category between 30-60%..

&&

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

$$

DISCUSSION...Salerno
AVIATION...Whittock
FIRE WEATHER...Salerno