Buckeye, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

Weather Forecast Discussion

798
FXUS65 KPSR 230105
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
605 PM MST Mon Dec 22 2025

.UPDATE...Updated 00Z Aviation Discussion.

&&

.KEY MESSAGES...

- Quiet weather with well-above normal temperatures will continue
  today across the region.

- A pattern change will bring more clouds and wetter weather to
  the area beginning tomorrow afternoon and persisting through
  late week with increased rain chances and gradually cooling
  temperatures.

&&

.SHORT TERM /TODAY THROUGH TUESDAY/...
Upper-level ridging is gradually shifting more into the Plains
today, but the Desert Southwest still remains under its influence
with 583-585dam H5 heights over AZ, which is above the 90th
percentile for this time of year. With the strong high pressure
influence, high temperatures this afternoon will once again be
upwards of around 15 degrees above normal and pushing daily record
highs. Phoenix broke its daily record high yesterday and will
likely break today`s 100+ year old record of 79 degrees with a
high forecast to reach 82 degrees. There will be increased high
clouds today, but forecast soundings suggest they will not be
optically thick enough to have any significant influence on the
temperatures.

Heading into tomorrow, the overall CONUS weather pattern will
become more amplified with ridging east of the Continental Divide
and a deep long-wave trough along the Pacific coast. This pattern
configuration will put the Desert Southwest under deep
southwesterly flow and help draw anomalous moisture into the
region. The deepening trough will push a moderate-strong AR
southward through CA and tap into some subtropical moisture. A
strong push of moisture from the subtropics is expected tomorrow,
with PWATs forecast to quickly rise from 0.3-0.5" early tomorrow
morning to as high 1.1- 1.3" (~300% of normal) by late in the
evening. A weak subtropical shortwave moving up with this initial
push of moisture will likely aid in the development of a band of
scattered gusty light showers starting out west over southeast CA
and southwest AZ around midday and moving into south-central AZ by
tomorrow evening through tomorrow night. Rainfall is expected to
be light with this first push, with accumulations ranging from a
hundredths to a couple tenths. Latest HREF has a 10-30% chance of
exceeding 0.2" of rain through early Wednesday morning in the
Phoenix area and increases up to 70-80% chance along the Maricopa-
Yavapai county border.

Afternoon high temperatures tomorrow will be slightly cooler than
today, with the highest degree of cooling, 5-8 degrees, expected
in the western deserts, while south-central AZ only cools 1-4
degrees. The cooling will be driven largely by an increase in the
specific heat capacity with the increasing moisture and cloud
cover. With the only minor cooling in Phoenix tomorrow, there is
potential to tie or break yet another daily record high. Latest
NBM forecast has a high of 80 in Phoenix and the record is 79
(1950).

&&

.LONG TERM /WEDNESDAY THROUGH NEXT WEEKEND/...
Following the shortwave trough, with the initial surge of moisture
Tuesday, there may be a brief break in shower activity Wednesday
morning into the afternoon, due to subsidence and drier mid-
level air in the trough`s wake. However, once the high-end
moisture levels arrive there will be shower chances at nearly all
times through at least Thursday (Christmas Day). The IVT axis,
associated with AR that will cause major impacts in SoCal, will
eventually push further inland into the interior deserts later
Wednesday through Thursday morning. While a lot of moisture will
be squeezed out in the SoCal coastal ranges, both GEFS and ENS
models show pretty high probabilities (60-90%) of IVT values >500
kg/ms reaching beyond the Colorado River during the mentioned
timeframe. This will lead to the best rain chances of the
forecast, with the latest NBM maintaining 70-90% PoPs from
Southeast CA through south-central AZ late Wednesday through
Thursday morning. Despite this outlook, there are still some model
differences in the evolution of this pattern which could limit the
coverage of rain showers in south-central AZ. A shortwave trough
helping guide the AR in SoCal is expected to track NE`ward from
SoCal through southern NV. This track will favor better forcing
and rain bands to track more through the mentioned area and parts
of northwest AZ. Deterministic models like the GFS, Canadian, and
experimental RRFS show the main rain band breaking up on the
southern end becoming more isolated or scattered as the IVT axis
shifts further east into AZ. The ECMWF holds the band together
more into south-central AZ.

The highest rainfall totals are projected across the upslope
areas and mountains where orographic lift will be maximized. The
latest QPF from WPC has rainfall totals ranging from over 1"
across the foothills and terrain north of Maricopa and La Paz
Counties and in western Joshua Tree National Park to between
0.20-0.50" in the Phoenix area and between 0.05-0.20" across the
rest of the lower deserts. Rainfall forecasts will become more
refined and potentially less uniform heading into the hi-res
model window. The one constant in the QPF forecast is that the
highest rain totals regionally will favor the terrain areas of
Yavapai and Mohave Counties, with GEFS and ENS still highlighting
these areas with 50-80% chances of >1" storm totals (Tue-Fri)

Rain chances will gradually decline Thursday afternoon through
Friday as subsidence and drying moves in above 700mb. However,
lingering trapped low-level moisture will still be enough to
support at least some spotty showers in the higher terrain areas
of AZ. A surface cold front and axis of moisture should also push
into SoCal again Friday, but most if not all of the moisture is
expected to rain out on the windward side of the mountains again.
There is a little better confidence in the pattern evolution going
into this weekend with the latest 12Z global models favoring a rex
block developing along the West Coast. The block will involve the
base of the long-wave trough splitting off into a closed low near
to off the SoCal coast. Details regarding how this pattern will
affect the Desert Southwest is a little less certain, with some
models tapping more sub-tropical moisture and pulling it northward
and others putting the region more under the influence of drier
ridging.

With the unsettled pattern evolving mid to late week, temperatures
are expected to gradually cool, but will remain above normal as
afternoon highs will top in the low to mid 70s. With the abundant
moisture and cloud cover that will be in place, overnight low
temperatures between the Wednesday through Friday time frame will be
quite warm for late December, in the upper 50s to around 60 degrees
and potentially breaking record warm lows across all three climate
sites (Phoenix, Yuma, and El Centro). Latest NBM has temperatures
cooling further, closer to seasonal levels this weekend.

&&

.AVIATION...Updated at 0045Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT;
No aviation weather concerns under high cirrus decks can be
expected during the next 24 hours. Winds will remain light
(generally AOB 8 kts). Current light and variable winds (with
some period of calm conditions) will become SE`rly overnight and
then go southerly tomorrow afternoon.

Late Tuesday afternoon/early Tuesday evening, lower decks of
clouds will begin to fill in (but CIGs should remain AOA 6 kft AGL
into the evening) as an area of virga and -SHRA pushes into the
region. Winds are expected to abruptly shift southwest/west ahead
of the virga/shower activity as it drifts eastward during the
evening hours.


Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation concerns will exist through Tuesday morning
under thickening high cirrus decks. Winds will remain light
(generally AOB 5 kts), exhibiting extended periods of variability
to nearly calm conditions. By late Tuesday morning and into the
afternoon VFR CIGs will fill in over the airspace as an area of
virga/-SHRA conditions pushes into the region from the southwest.
Ceilings are currently expected to lower to around 8-10 kft, but
could go lower. CIGs are expected to remain above IFR.


&&

.FIRE WEATHER...
High pressure across the region will continue to promote dry and
tranquil weather today along with unseasonably warm temperatures
as afternoon highs top out in the upper 70s to low 80s across the
lower deserts. Winds will generally be light under 15 mph and tend
to follow typical diurnal trends. Afternoon MinRHs will range
between 20-35% with good overnight recoveries of 50-75% tonight.
A weather system is expected to affect the region beginning
tomorrow, bringing higher moisture, increased rain chances, and
cooler temperatures. The initial strong push of moisture will come
during the day tomorrow, with afternoon MinRHs still in the 20-30%
range across south-central AZ and 35-50% across western areas.
Best rain chances will be between Wednesday afternoon and Thursday
morning. MaxRH values tomorrow night then jump to 75-100% area-
wide. In the following days, MinRHs will be in the 45-70% range
each day.

&&

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

$$

SHORT TERM...Benedict
LONG TERM...Benedict
AVIATION...Berislavich/Whittock
FIRE WEATHER...Lojero/Benedict