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000
FXUS65 KPSR 140520
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1020 PM MST Sat Apr 13 2024

.UPDATE...Updated 06Z Aviation Discussion.

&&

.SYNOPSIS...
Another warm day this afternoon before cooling temperatures
settle into the region going into early next week. Breezy to windy
conditions will continue through early next week as well, with
Wind Advisories in effect for portions of southeastern California.
Building high pressure and warming temperatures are anticipated
through the middle and latter portions of next week.

&&

.DISCUSSION...
Sunny skies encompass the region this afternoon, with temperatures
reaching into the upper 80s to low 90s across the southcentral
Arizona deserts this afternoon. This will be the last chances for
90 degree highs across the region until the early to middle of
next week, as a negative height anomalies begin to break down the
residual ridging hanging onto the Desert Southwest.

The latest satellite depicts this upper low spinning off the
central California coast this afternoon, with this trough expected
to meander eastward into the Great Basin by tomorrow. Gradient
winds will be the only sensible weather impact across the region
over the next few days, as surface low pressure moves across the
region. The strongest winds are expected to remain out across the
western districts contained in Imperial County. Wind Advisories
are in effect for those areas for today and tomorrow, as winds
gusting 40-50 mph will be common through tomorrow night.

Heading into early next week, the trough will slide east of the
region, with mid-level heights building once again going into the
middle and latter portions of next week. Expect temperatures will
trend warmer once again, with highs in the 90s returning as early
as Tuesday for the western deserts and spreading eastward into
southcentral Arizona by Wednesday. Ensembles have shifted more
towards a warmer scenario going into late week, with a ridge
amplifying across the West Coast. Thus, probabilities of reaching
triple digits across the lower deserts as early as Thursday are
now around 40-50%, with chances in excess of 20% continuing into
next weekend. In this scenario, we may see our first chances of
not only hitting triple digits, but also challenging the record
highs for this time of year late next week. This scenario would
also result in the HeatRisk reaching the Moderate category for the
first time this year.

&&

.AVIATION...Updated at 0520Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Easterly winds will establish over the next few hours at KPHX. A
similar evolution in the wind directions can be expected tomorrow
to that of what we saw over the last few days; winds veer SE-SSE
over the late morning hours, followed by a southerly cross runway
component with sustained speeds aob 10 kts and occasional gusts
into the mid teens midday, and SW winds establishing in the mid-
late afternoon. Gusts are anticipated to peak in the upper teens
to low 20s. Tomorrow evening, a dry cold front will pass over the
Phoenix area, which could lead to westerly gusts persisting later
into the evening, and confidence is moderate that winds will
remain west through tomorrow night. Mostly clear skies will
prevail through the period.

Southeast California/Southwest Arizona including KIPL and KBLH:
The primary aviation weather concern through the TAF period will
be gusty winds out of the W at IPL and SW at BLH, under mostly
clear skies. Elevated winds are expected to persist through the
TAF period at IPL (except for perhaps a few hours before sunrise
tomorrow), and winds will calm between 07-09Z at BLH before
picking back up shortly after sunrise tomorrow morning. Although
LLWS criteria are unlikely to be met, times where the surface
decouples sufficiently overnight could lead to 10-20 kts of shear
between the surface and 2 kft AGL. Gusts are expected to peak
between 30-35 kt and occasionally up to 40 kts late afternoon into
the early evening at IPL, whereas gusts will peak between 25-30
kt at BLH. During the strongest gusts, reduced visibilities from
blowing dust will be possible, particularly at IPL.

&&

.FIRE WEATHER...
With dry weather prevailing, temperatures will retreat closer to the
seasonal normal through the first half of next week before rapidly
warming back into an above normal category during the second half of
the week. A weather disturbance passing to the north of the area
will result in very breezy afternoon conditions the next several
days with the strongest gusts across western districts, where Wind
Advisories are currently in effect for today and tomorrow. As
minimum afternoon humidity levels fall into a 10-25% range, a
locally elevated fire danger will exist through Monday. As
temperatures warm next week, minimum humidity levels will dry
further into a 10-20% range with single digits common across
lower desert locations. Overnight recovery will turn poor to fair
in a 20-40% range. However, lighter wind speeds will preclude a
greater fire danger and provide an excellent opportunity for
prescribed burning during the middle of next week.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...Wind Advisory until 6 AM PDT Monday for CAZ562.

     Wind Advisory until 11 PM PDT this evening for CAZ563-566-567.

     Wind Advisory from 3 PM to 11 PM PDT Sunday for CAZ563-566-567.

&&

$$

DISCUSSION...Young
AVIATION...Whittock
FIRE WEATHER...Young/18