High Wind in California, January 8, 2025

Area Forecast Discussion
National Weather Service Phoenix AZ
346 AM MST Wed Jan 8 2025

.SYNOPSIS...
A cutoff low pressure system will continue to progress through the
region today, resulting in widespread breezy to windy conditions and
widely scattered showers/virga. Much cooler temperatures will follow
in the wake of this system with highs remaining below normal through
this weekend. Morning lows will also be significantly colder with
some desert locales expected to reach the freezing mark beginning
Thursday morning.

&&

.DISCUSSION...
Latest mid-lvl wv imagery and 500 mb streamline analysis reveals a
cutoff low situated over the Baja Del Norte. Our forecast region
is located just north of this feature in the deformation axis/band
which has set up over southcentral AZ. Unfortunately this system
is currently moisture starved and precipitation has been hard to
come by. Despite adequate lift and divergence aloft, the lack of
low lvl moisture has been a limiting factor in precipitation
reaching the ground. The main impacts with this system so far has
been winds. A strong mid tropospheric jet coupled with a tight
pressure gradient near the sfc has resulted in wind gusts in the
30- 50 mph range across southeast CA and portions of southcentral
AZ. Gusty winds will persist today, especially after sunrise as
strong winds aloft mix down to the sfc. A Wind Advisory remains in
effect until 21Z (2PM CST) for portions of southeast CA, the
Lower Colorado River Valley, in addition to the foothills of E
Maricopa and N Pinal Counties where the strongest gusts will
reside. The most notable impacts with these winds will be
difficult driving conditions for high-profile vehicles and
localized dense blowing dust channels. The I-10 corridor in
southeast CA and Pinal County, AZ will have the greatest risk
for these impacts through this afternoon.

Heading into tonight, the center of the upper low will continue to
weaken and push southward into N MX. As this occurs, precipitation
chances will come to an end and wind speeds will subside region-
wide. Dry air will begin to filter into the region from the NW as
the system pulls away from our area. This dry air coupled with
clearing skies will allow temperatures to plummet on Thursday
morning. Most lower desert communities will see morning lows in
the mid 30s to low 40s early Thursday, however some locations will
see lows dip below freezing. Therefore, the previous Freeze Watch
has been upgraded to a Freeze Warning for Globe/Miami, San
Carlos, Superior, Wickenburg, and lower elevations of N Pinal
County where temperatures are expected to fall into the upper 20s
to low 30s. A reinforcing shot of cool air will arrive Thursday
afternoon as a secondary shortwave trough dives south into far E
AZ. The trajectory of this trough looks to remain east of the
region which will keep any precipitation chances well off to the
east. The 700-500 mb hght gradient will tighten on the back side
of this system, leading to another bout of gusty winds primarily
across SE California and SW Arizona where gusts up to 25-35 mph
will be possible. Highs will be much closer to seasonal norms
Thursday afternoon in the low to mid 60s across the lower deserts
with 50s in the higher terrain.

Ensemble clusters are in good agreement that negative hght anomalies
and overall troughing will linger into this weekend which means we
will continue to see near to slightly below normal temperatures from
Friday through at least Monday. High temperatures should remain in
the low to mid 60s across the lower deserts (normal high for Phoenix
is 67 degrees). We will also likely continue to see cold mornings
with lows settling into the 30s and 40s. There is currently a
greater than 70% chance for locations that are currently in the
Freeze Warning to see a recurrence of freezing temperatures each
morning from Friday through Monday. The current Freeze Warning is
in effect through Friday morning, but will likely need to be
extended into this weekend. The coldest morning according to the
NBM looks to be Sunday where lows could even fall into the mid to
upper 30s in the Phoenix Metro. Other than the cooler than normal
temperatures, expect dry conditions to persist into early next week.

&&

.AVIATION...Updated at 0505Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Gusty E/NE winds will be the main weather concern through Wednesday
afternoon as 10-15K ft AGL cigs will prevail the majority of the
period. Periodic wind gusts around 25kt will affect the airspace
tonight, however several lulls in these stronger gusts should be
expected through mid morning. Virga and isolated light -SHRA will be
common overnight into Wednesday morning which could result in very
localized brief erratic winds and enhanced speeds. Confidence is
excellent that stronger, more widespread gusts will settle over the
entire metro mid/late morning with mixing yielding frequent 25-35kt
gusts into mid/late afternoon before relaxing considerably by
sunset.

Southeast California/Southwest Arizona including KIPL and KBLH:
Strong, gusty north winds will be the primary weather hazard through
Wednesday afternoon under periods of 10K ft cigs. Strong wind gusts
30-40kt (and occasionally higher) will affect KBLH into the
overnight with lesser speeds at KIPL. Periods of BLDU and lofted
dust will be likely around KBLH with brief periods of MVFR vsby
restrictions. Visibility impacts at KIPL should be minimal though
lofted dust will be possible affecting slantwise vsby. Partial
decoupling and a weakened pressure gradient may allow gusts to abate
somewhat towards sunrise, however widespread gusts 25-30kt should
resume by late Wednesday morning before finally relaxing mid/late
afternoon.

&&

.FIRE WEATHER...
A low pressure system will continue to progress through the
region today, resulting in breezy to locally windy conditions.
Easterly winds will be strongest mid-morning today with gusts
ranging from 40-50 mph across southeast CA and foothills of
E Maricopa and N Pinal Counties. Elsewhere, gusts ranging from
20-35 mph can be expected through this afternoon before gradually
diminishing around sunset. Light precipitation will be possible
across south-central AZ today, although little to no measurable
accumulations are anticipated. Relative humidity will bottom out
between 20-35% across the eastern districts and as low as 15-25%
in the western districts this afternoon. Overnight recovery will
range from poor along and west of the Colorado River to good
across south-central AZ. A drying trend is expected through the
remainder of this week.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Wind Advisory until 2 PM MST this afternoon for AZZ530-541-542-
     545-547-549-551>553-555-557-558-561-562.

     Freeze Warning from midnight tonight to 9 AM MST Thursday for
     AZZ534-552-553-556-560>562.

     Freeze Warning from midnight Thursday night to 9 AM MST Friday
     for AZZ534-552-553-556-560>562.

CA...Wind Advisory until 1 PM PST this afternoon for CAZ560-561-564-
     565-568>570.

&&

DISCUSSION...Salerno
AVIATION...18
FIRE WEATHER...Salerno