National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS65 KPSR 242145
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
245 PM MST Wed Apr 24 2024


.SYNOPSIS...
Two weather systems moving through the region over the next few
days will lead to much cooler temperatures with desert highs in
the low to mid 80s Thursday through Saturday. There will also be a
significant uptrend in windiness. The strongest winds will be over
southeast California tonight and again Friday. Precipitation
chances over the forecast area will be limited mainly to La Paz
County very late tonight and then south-central Arizona late
Friday night and Saturday morning. A warming trend begins Sunday
with desert highs climbing well into the 90s by Monday and
flirting with 100 Tuesday and Wednesday.


&&

.DISCUSSION...
A pattern change has begun with the high pressure ridge moving
eastward as an upper low (centered off the SoCal coast) advances
eastward. That system moves across our forecast area tonight and
during the day Thursday. The system will have to overcome a warm
and dry airmass and moisture advection looks to be modest.
However, there will be a cool front along with some dynamical
forcing to try to overcome the limitations. To varying degrees,
deterministic CAMs are showing a batch of showers starting up over
La Paz County late tonight and tracking northeastward brushing
northern portions of Maricopa County as well. Some subtle upward
adjustments were made to the NBM PoPs to increase the area with
slight chances. The shower activity increases just north over the
FGZ forecast area during the day Thursday due to a combination of
more orographic lift and destabilization (anticipate some
thunderstorms in the mix there as well).

The next system to affect the forecast area will be a
strengthening short wave originating from the Pacific Northwest.
The overland trajectory isn`t ideal for moisture advection but the
models have trended stronger with this feature and moisture
availability trends up a little bit. Plus, there will be some
preconditioning of the atmosphere from the previous system leading
to more widespread PoPs over AZ. However, those PoPs will still be
mainly limited to northern AZ but more of south-central AZ
(including portions of Greater Phoenix) will now have at least a
slight chance for precipitation - mainly late Friday night and
Saturday morning.

With the passage of these systems, a significant uptrend in
breeziness/windiness can be expected. As is often the case, the
strongest winds for our forecast area will be over southeast CA. A
Wind Advisory is in effect there tonight with a new Advisory there
for Friday afternoon and evening. A new Advisory has also been
issued for portions of southern Gila County for the same time
frame. The southwest corner of Imperial County continues to have
a longer lived Advisory in effect tonight through Friday evening.
Though there are any Advisories for Thursday, it will still be at
least breezy; likewise with Saturday.

After highs in the 80s Thursday through Saturday, a warming trend
begins Sunday with desert highs climbing well into the 90s by
Monday and flirting with 100 Tuesday and Wednesday.


&&

.AVIATION...Updated at 1808Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Southerly winds, with some SW-SE variability is anticipated
through 22-23Z this afternoon before a more distinguished SW
develops. Winds increase this afternoon, with occasional SW gusts
up to 20-25 kts. Confidence in wind directions tonight is low.
Surface decoupling should allow winds shift back to an E to SE
component, however it may be brief and winds may veer back S-SW
with a weather system moving through. There is a low chance
(5-10%) for some showers to sneak into Phoenix Thursday morning
between 12-17Z. Most activity will pass to the north, where a few
thunderstorms may also develop. FEW to SCT high clouds will clear
by this evening. Then FEW, to briefly SCT, clouds as low as 5-6K
ft may develop Thursday morning and then rise to 10-12K ft during
the day.

Southeast California/Southwest Arizona including KIPL and KBLH:
Very breezy to windy conditions are expected at both terminals
through most of the TAF period. Winds will be strongest during the
late afternoon and evening, with westerly gusts peaking up to
35-40 kts at KIPL this evening and southwesterly gusts peaking up
to 25-30 kts at KBLH. Some reprieve from the gustiness is
anticipated overnight, but sustained speeds will likely remain
elevated in the 10-20 kt range. The strong winds will be capable
of kicking up dust, but the wind direction at KIPL is not ideal
for significantly reduced visibility (MVFR or lower). There is a
low chance (5-10%) for a high-based shower to develop near KBLH
between 5-10Z before quickly moving off to the east. SCT mid-level
clouds will develop Thursday morning and clear by the afternoon.

&&

.FIRE WEATHER...


&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...Wind Advisory from 2 PM Friday to midnight MST Friday night for
     AZZ557-558.

CA...Wind Advisory from 2 PM Friday to midnight PDT Friday night for
     CAZ560-563-565>567.

     Wind Advisory until 3 AM PDT Thursday for CAZ560-563-565>567.

     Wind Advisory until midnight PDT Friday night for CAZ562.

&&

$$

DISCUSSION...AJ
AVIATION...Benedict
FIRE WEATHER...AJ