El Mirage, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

598
FXUS65 KPSR 282339
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
439 PM MST Sun Dec 28 2025

.UPDATE...Updated 00Z Aviation Discussion.

&&

.KEY MESSAGES...

- High pressure will spread into the region early this week
resulting in dry and locally breezy conditions with temperatures
slightly above normal.

- An unsettled weather regime moving into the region during the
latter half of the week will lead to periods of increased light rain
chances.

&&

.SHORT TERM /Today through Tuesday/...
A blocked Conus flow pattern was materializing this afternoon with
pronounced Pacific ridging building eastward causing shortwave
energy cresting the ridge apex to become sheared and split either
downstream into the central plains, or retrograded into the Rex
block base off the southern California coast. This pattern is
promoting sfc pressure rises throughout the Great Basin forcing a
cooler, drier airmass southward into the Southwest. Objective
analysis already indicates strengthening 20-25kt H9-H8 northerly
winds surging down the lower Colorado River valley. The enhanced
pressure gradient will tighten overnight via thermal processes and
translate into central/eastern Arizona. This typical winter pattern
of northeast flow will be common through Tuesday morning yielding
gusty ridge top winds (up to 30 mph) and highly varying low
temperatures based on mixing effects.

As high pressure intensifies through the southern high plains,
prolonged sfc-H7 E/SE flow will force an enhanced backdoor moist
push up the Rio Grande valley. With a col weakness in the midlevel
height field, its conceivable an isolated shower could leak into
southern Gila County Monday afternoon, but otherwise partly cloudy
skies, increasing heights, and seasonably deep mechanical mixing
will result in steadily warming temperatures. While ensemble
guidance spread is somewhat larger than would be expected,
confidence is very good that readings 4F-8F above normal will be
common.

&&

.LONG TERM /Wednesday through Sunday/...
The weather pattern for later this week remains very complicated
with an East Pacific Rex Block slowly evolving, and the associated
southern stream cutoff low drifting northeast during the middle part
of the week. Upper level ridging is likely to still dominate across
much of the Southwest through early Wednesday, but as the cutoff low
begins to shift closer, moisture quickly begins pushing northward
into our region. Ensemble forecasts suggest total column PWATs
rising near 1.00" of nearly 200% of normal across southern
California and SW Arizona Wednesday before increasing further and
spreading north through the rest of the region into Thursday.
However, the bulk of this moisture will be aloft and it will take
Wednesday evening into Thursday morning for top down saturation to
support greater rain chances. Virga and scattered light showers
should initially form late Wednesday, with chances for measurable
rainfall steadily increasing through the evening and overnight. At
this time, the preponderance of model output suggests only light
rainfall amounts (generally 0.10" or less) Wednesday evening and
overnight with perhaps somewhat higher amounts in preferred upslope
locations.

As moisture peaks Thursday, better chances for occasional showers
will exist as theta-e advection acting upon PWATs as high as 1.25"
becomes the primary ascent mechanism. Upper level forcing will
largely be minimal, so reliance on this low and mid level forcing of
a higher moisture content airmass will be critical and highly
focused on upslope areas across central Arizona. While NBM PoPs in
the previous overnight iteration had decreased into a more
reasonable level given the pattern configuration and conceptual
model, the latest mandated output has flopped back to elevated
levels seemingly being influenced by a small handful of CMC and EPS
extreme outliers. As a result, have cut values back in line with the
previous POP/QPF forecast staying mainly in a 20-30% range for the
lower deserts of SE California/SW Arizona initially, then boosting
closer to 40-60% and shifting better chances across south-central
into eastern Arizona Thursday.

Assuming the event plays out close to this forecast, rainfall
amounts Wednesday night through Friday morning should be quite light
with most areas accumulating less than 0.25" with some localized
higher amounts 0.25-0.75" possible (especially across higher terrain
north and east of Phoenix). While a follow-on trough remains
possible next weekend, the majority of NAEFS members either stall
the negative height anomalies over the East Pacific or miss our
region to the north entirely. Enough evidence exists to maintain
some lower end POPs through the weekend, however cut values down
from the seemingly overblown NBM output. Otherwise, expect high
temperatures to remain fairly stable from near normal to maybe 4-7
degrees above normal. Overnight temperatures will become quite mild
later in the week with lows mostly in the 50s for a few days due to
the cloudy skies.

&&

.AVIATION...Updated at 2338Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No major aviation weather concerns expected through the TAF
period. Winds will continue to be light out of the NW for the
evening and through the overnight hours. Speeds will generally be
aob 10kts before likely increasing to above 10kts by late tomorrow
afternoon and switching out of the east. FEW-SCT high cirrus
clouds expected through the period.

Southeast California/Southwest Arizona including KIPL and KBLH:
No major aviation concerns are expected through the TAF period.
Wind directions will generally be out of the N-NW with speeds at
KBLH aob 10-15 kts with periods of gusts up to 20 kts this
afternoon, KIPL will remain lighter through the TAF with speeds aob
6-8 kts. Expect periods of gusts to subside at KBLH by this evening.
FEW-SCT high cirrus clouds are forecast to move in this afternoon
and will prevail through the TAF period.

&&

.FIRE WEATHER...
Dry weather with temperatures near to slightly above normal will be
seen through at least Monday. Minimum humidity levels will tumble
into a 25-35% range today with somewhat lower values Monday. Winds
will increase today, initially through the lower Colorado River
Valley, then across ridge tops of eastern districts tonight and
Monday where gusts of 20-30 mph will be common. Moisture will begin
to seep back into the region midweek raising humidities and bringing
rain chances by around Thursday.

&&

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

$$

SHORT TERM...18
LONG TERM...Kuhlman/18
AVIATION...Ryan/95
FIRE WEATHER...Kuhlman