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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS65 KPSR 190541
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1041 PM MST Thu Apr 18 2024

.UPDATE...
Updated Aviation section.

&&

.SYNOPSIS...
Dry conditions and above normal temperatures will prevail through
early next week. The warmest days over the next week are expected to
be Sunday and Monday, with a few warmer locations potentially
reaching 100 degrees. Otherwise, high temperatures in the low to mid
90s will be common across the lower deserts through next Tuesday
before a gradual cooling trend takes hold during the latter half of
next week. A weak disturbance will pass over the Desert Southwest to
end this week, bringing widespread breezy conditions tomorrow.

&&

.DISCUSSION...
A deck of high clouds is currently streaming over the region ahead
of a weak shortwave trough as it moves eastward towards the Southern
California Coast. With a ridge of high pressure in place over the
Desert Southwest, high temperatures are still expected to approach
the low-to-mid 90s across much of the lower deserts today despite
the cloud cover. Heights aloft will become slightly depressed as the
shortwave traverses the region late tomorrow into Saturday, but
daily afternoon high temperatures will remain relatively stable
tomorrow and Saturday under sunny skies. The main sensible impact of
this shortwave will be widespread breezy conditions (gusts to 15-25
mph) tomorrow afternoon, with the strongest winds anticipated in
Imperial County in the evening. Gusts across the lower elevations of
central and eastern Imperial County will likely approach 30-35 mph
late tomorrow afternoon into the evening, with even 90th percentile
HREF gusts remaining below 40 mph across much of the County except
over the highest elevations in the far southwestern corner.

Ridging will prevail once again in the wake of the shortwave trough
with forecast highs warming into the mid-to-upper 90s Sunday and
Monday. A few warmer locations may even approach the century mark
during this time, though probabilities for reaching or exceeding 100
degrees remain low (up to 10-30%). Temperatures may not be exceeding
100 degrees at this point, but the proper heat safety precautions
should still be exercised as temperatures warm up. Widespread Minor
to at times locally Moderate HeatRisk will continue through the next
week. Global ensembles then show a deeper trough affecting the
Desert Southwest during the latter part of next week, though
considerable uncertainty exists. For now, the NBM shows a cooling
trend for the latter half of next week with the potential for
temperatures to cool back down to near normal readings by along with
increased breezy conditions.

&&

.AVIATION...
-- Changed Discussion --
Updated at 2341Z.

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

Nocturnal downvalley/drainage patterns have begun over the
Greater Phoenix area with KPHX expected to have easterly
directions in place by 10Z. Daytime winds Friday will follow a
similar pattern as Thursday with a period of southerly winds in
the midday/early afternoon time frame followed by a mid to late
afternoon onset of southwesterly/westerly. As for sky cover,
cirrus will thin out by 09Z or so with with clear skies the rest
of the TAF period.


Southeast California/Southwest Arizona including KIPL and KBLH:

At KIPL, light westerly winds are expected to prevail the rest of
the night and much of the day before minor westerly gustiness
(20-25kts) develops between 00Z-02Z Saturday. At KBLH, light and
variable winds will be in place before minor southerly breeziness
(gusts 15-20kts) develop Friday afternoon. As for sky cover,
expect clear skies the rest of the TAF period.
-- End Changed Discussion --

&&

.FIRE WEATHER...
Dry weather will continue through at least the next couple of
days. Above normal afternoon temperatures will continue through
the remainder of the week as lower desert highs top out in the
low to mid 90s. Winds will remain light today with typical
afternoon breezes into the teens at times. A weak weather system
will lead to afternoon gusts increasing Friday to 15-25 mph for
many areas, while areas across Imperial County potentially see
gusts in excess of 30 mph Friday evening. Min RHs will continue to
fall into the 5-15% range each day.

&&

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

$$

DISCUSSION...Whittock
AVIATION...AJ
FIRE WEATHER...Smith