South West Weather

666
FXUS65 KPSR 100532
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1032 PM MST Thu Apr 9 2026

.UPDATE...Updated 06Z Aviation Discussion.

&&

.KEY MESSAGES...

- Dry conditions with above normal temperatures will prevail
  across the region through the end of the week

- An approaching weather system will result in increased cloud
  cover, breezy conditions, and cooling temperatures this weekend

- Another system early next week will result in further cooling
  with temperatures falling below normal Monday and Tuesday

&&

.SHORT TERM /Today through Saturday/...
Flat, subtropical ridging was still holding over the SW Conus
early this afternoon as a slow moving cyclone off the California
coast edges eastward. Upstream meridional flow and increased
blocking will ensure synoptic features only progress gradually
eastward, however a steady march towards cyclonic flow with
lowered midtropospheric heights will ensue over the next 72 hours.
H5 heights in a 576-579dm will be maximized today with levels
eroding closer to a 570-574dm range by Saturday afternoon.
Correspondingly, H8 temperatures eclipsing +20C this afternoon
will languish closer to +15C Saturday with numerical guidance
convincingly advertising afternoon highs gradually cooling from
much above levels to just a few degrees warmer than the seasonal
normal over the weekend.

While the majority of the region will experience dry conditions
through Saturday, a few subtle embedded shortwaves juxtaposed with
enhanced midlevel moisture may support a couple isolated showers
over higher terrain areas Friday. The main focus should remain in
western New Mexico where better ascent and moisture will combine,
however HREF members indicate a non-zero chance of showers
clipping southern Gila County. Otherwise, strengthening winds with
localized higher gusts will be the primary weather issue the next
several days given modest height falls and seasonally deepening
mixing depths. The most pronounced winds should remain relegated
to far western Imperial County where sundowner/enhanced mountain
waves activity will be preferred given the synoptic pattern.
However, the lagging synoptic system and gradual, modest falls may
limit the magnitude of winds cresting higher terrain with a more
optimal setup not arriving until Sunday or Monday. Nevertheless,
model evidence hints at speeds flirting with advisory criteria
Friday and Saturday, but not sufficient in time and space to
justify any headlines just yet.

&&

.LONG TERM /Sunday through Wednesday/...
The cooling trend will continue early next week as large scale
troughing becomes established over the Intermountain West. The
first in a series of shortwaves embedded in the large scale trough
will lift north of our region with a majority of moisture focused
into E New Mexico and W Texas. Therefore, NBM PoPs have decreased
dramatically and are now only around 10-15% at most, even in the
higher terrain areas NE of Phoenix. The main weather impact this
weekend will be winds as the mid-lvl height gradient remains
compact across the entire region. Gusts will range from 20-25 mph
across the lower deserts and upwards of 30-35 mph in the higher
terrain areas, especially at mountain peak level. Winds on Sunday
may reach low end advisory criteria across portions of SE
California and the high terrain of south-central Arizona.

Ensemble members and deterministic guidance are in good agreement
that a deeper shortwave trough will progress through the Desert
Southwest Monday into Tuesday with H5 anomalies reaching a maximum
on Monday. This will be the coolest day of the forecast period
with lower desert highs mainly in the low to mid 70s and lows in
the 50s. Increasing cloud cover and even a few passing showers
will be possible across the northern fringes of the forecast area
Monday into early Tuesday as the trough axis passes overhead.
Drier air will begin to filter into the region behind the
departing weather system late Tuesday. As H5 anomalies transition
from negative to neutral, temperatures will rebound from slightly
below normal on Tuesday to near normal by Wednesday.

&&

.AVIATION...Updated at 0532Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No major aviation weather impacts are expected through Friday
under SCT to BKN mid and high cloud decks. Winds will follow a
nearly identical diurnal/nocturnal trend to the past 24 hours,
with light easterly winds in the morning and gusty W/SW winds in
the afternoon (gusts up to 20 kts). No slantwise visibility
impacts are expected.

Southeast California/Southwest Arizona including KIPL and KBLH:
Breezy westerly winds will persist through most of the TAF period
at KIPL with strongest gusts, as high as 25-30 kts, expected in
the late afternoon through the evening. KBLH will also see SW
gusts up to 20-25 kts in the afternoon and evening, but will see
light winds during the overnight period tonight with some light
variability to calm conditions. SCT to BKN mid and high cloud
decks will continue to pass over the area through Friday morning
and become FEW by the evening.

&&

.FIRE WEATHER...
Dry conditions and well above normal temperatures will persist
through the end of this week. MinRHs will range from 10-15% today
before increasing above 15% starting on Friday. Overnight recovery
will generally range from poor to fair across the region over the
next couple nights, however low level moisture will trend upward by
this weekend resulting in much better recovery up to 50-70%. Winds
will follow typical diurnal tendencies, however enhanced upslope
gustiness can be anticipated especially across the western districts
beginning this afternoon. A weather system will move into the region
this weekend, resulting in continued breezy to locally windy
conditions and much cooler temperatures. Scattered showers will be
possible mainly over the higher terrain of southcentral AZ, but CWR
will remain low