San Tan Valley, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

126
FXUS65 KPSR 232337
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
437 PM MST Mon Dec 23 2024

.UPDATE...Updated 00z Aviation Discussion...

&&

.SYNOPSIS...
Dry, and warm weather will continue for the start of the week
before a cold front passes delivering much cooler temperatures
Tuesday into Wednesday. Winds will increase across the region with
this cold front, but rain chances will remain minimal across the
lower deserts. Temperatures are favored to trend back toward well
above normal readings by this weekend.

&&

.DISCUSSION...
Partly cloudy to mostly clear sky conditions encompass the region
early this afternoon, as the next low pressure system begins to
move into the Pacific Northwest. This system will deepen over the
next couple of days, resulting in some sensible weather changes
across the region by the middle of the week. For today,
temperatures will rival record levels once again, as lower desert
highs will reach into the upper 70s. Highs will continue to run
near record levels in the upper 70s tomorrow as well.

Dampened ridging across the region will amplify again tomorrow
ahead of the aforementioned troughing feature across the eastern
Pacific, resulting in the well above normal temperatures
continuing. The ridging will quickly slide eastward as the trough
deepens across the West Coast tomorrow, ahead of significant
height falls across the region going into the middle of the week.
A dry cold front is set to move across the region from the
northwest with this low pressure system Tuesday into Wednesday,
which will usher in much cooler temperatures beginning Wednesday.
Winds will also increase across the region, most notably across
the Lower Colorado River Valley (20-30 mph gusts) and the
favorable terrain areas of southwestern Imperial County (40-50 mph
gusts). The strongest winds will have a relatively short duration,
so no advisory has been issued for southwestern Imperial County.

Dry northwesterly flow will continue across the region through
the end of the week, with some ridging trying to build behind the
trough that will exit east of the region by Thursday. A second
trough from the persistent longwave will deepen across the Great
Basin on Thursday, keeping northwesterly flow across the region
through the end of the week. Temperatures will continue to run
several degrees above normal, with lower desert highs in the upper
60s to lower 70s through Friday.

Depending on how anomalous this second trough becomes will dictate
how long these cooler temperatures will persist, as ensembles
(mainly because of the GEFS) show a bit of spread on the upper
level pattern going into this weekend. However, there is
consensus on ridging building back into the region from the
southwest, which will result in warming temperatures over the
weekend. Thus, expect well above normal temperatures to redevelop
across the region by the beginning of next week. Looking into the
far extended, another trough looks likely to traverse across the
West Coast early next week, but none of the guidance would suggest
anything more than potentially cooling temperatures would occur
with this pattern change.

&&

.AVIATION...Updated at 2335Z.

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

No major aviation weather concerns will exist through Tuesday
afternoon under periods of passing SCT to occasional BKN cloud
decks aoa 20 kft. A diurnal wind pattern will continue to persist
with westerly winds expected through early this evening before
switching out of the east later in the evening hours. Overall wind
speeds will remain light aob 7 kts with extended periods of
variable to calm conditions. There is some uncertainty of a full
westerly shift occurring later Tuesday afternoon with the overall
wind direction likely to exhibit variable characteristics.

Southeast California/Southwest Arizona including KIPL and KBLH:

Gusty westerly winds developing Tuesday afternoon, especially at
KIPL, will be the main aviation weather issue through the TAF
period. In the meantime, winds into Tuesday morning will remain
very light aob 5 kts with extended periods of variable to even
calm conditions. Heading into Tuesday afternoon, especially during
the mid to late afternoon hours, a more defined westerly wind
component will develop with overall wind speeds increasing,
especially at KIPL where gusts could be approaching 20 kts. SCT to
occasionally BKN cloud decks aoa 20 kft will be common through
Tuesday afternoon.

&&

.FIRE WEATHER...
Dry conditions with temperatures around 10 degrees above normal will
continue for the beginning of the week. A weather system and an
associated cold front will bring cooler conditions along with
increasing winds to the region Tuesday into Wednesday. Winds will be
strongest across portions of southeast California where gusts could
climb in excess of 30 mph at times going into Tuesday evening. Rain
chances are expected to remain minimal with the best chances
remaining across the Arizona high terrain. Min RHs today will be
around 10-20% for most places before increasing to around 15-25%
Tuesday. Dry conditions with near to slightly above normal
temperatures are favored to persist through the end of the workweek
before temperatures trend back toward well above normal this weekend.

&&

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

$$

DISCUSSION...Young/Ryan
AVIATION...Lojero
FIRE WEATHER...Smith