709
FXUS65 KPSR 041123
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
423 AM MST Wed Nov 4 2026

.UPDATE...Updated Aviation Discussion.

&&

.KEY MESSAGES...

- Major waterways such as the Salt and Gila rivers will continue
  to experience high volume flows through at least the end of the
  week due to dam releases.

- With the exception of a slight chance of mountain showers late
  this week, dry weather will be common through at least early
  next week.

- Temperatures a few degrees below normal will warm very close to
  the daily normals by the end of the week through early next
  week.

&&

.SHORT TERM /Today through Friday/...
Early morning objective analysis depicts an omega block type flow
pattern across the Conus with negative height anomalies situated
over the Great Basin and upper Midwest respectively, while pinched
ridging has settled over the northern plains/south-central Canada. A
strong jet level u-wind component along the southern tier of the US
will ensure this blocking pattern is resolved quickly over the next
48 hours transitioning into progressive, low amplitude flow pattern
featuring elongated, positively tilted troughs. By the end of the
week, there`s sufficient ensemble evidence of weakness in the height
fields over the Southwest resulting in the formation of a cutoff
low, albeit with low confidence on the placement and intensity. This
could result in a few light showers over mountains of eastern
Arizona Friday, though moisture levels will be severely limited.

Regardless, under local quasi-zonal flow, H5 heights will generally
hover in a 576-582dm range the next several days with slowly warming
lower tropospheric temperatures. Given the generally dry pattern,
forecast confidence is excellent that temperatures around 4F below
normal will rebound very close to the seasonal average by the end of
the week.

&&

.LONG TERM /Saturday through Tuesday/...
During the weekend, some semblance of a Rex block (or omega block)
will develop in the southern stream with weak troughing over
northern Mexico and broad ridging across the Great Basin/central
Rockies. While the precise orientation and positioning of salient
features remain uncertain based on notable ensemble differences, the
overall pattern will promote surface pressure rises over the
intermountain West and dry N/NE boundary layer flow. Based on the
pattern, periods of breezy northeast winds are likely at times over
the weekend and early next week, though nothing particularly strong
or unusual for this time of year. At some point early next week, the
bulk of ensemble members eject the northern Mexico wave through the
forecast area bringing enhanced mid/upper level moisture. It remains
to be seen whether this process can overcome the dry boundary layer
airmass, with the highest odds suggesting dry weather persisting.
With H5 heights remaining nearly steady state in a 580-584dm range,
temperatures should follow a near persistence trends with readings
not terribly far from climatology.

&&

.AVIATION...Updated at 1123Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT; and
Southeast California/Southwest Arizona including KIPL and KBLH:

No aviation weather impacts expected through the next 24 hours
under mostly clear skies. Winds will be light, below 10 kts, at
all terminals through the TAF period. For the Phoenix Metro,
typical diurnal E-W pattern will prevail. At KBLH and KIPL, winds
mostly favor W-N components. All terminals will also experience
extended periods of light variability and calm conditions.

&&

.FIRE WEATHER...
While a stray shower may affect mountains of eastern districts
Friday, the area will remain dry with little to no chance of wetting
rainfall through early next week. Minimum afternoon humidity levels
will largely fall into a 20-30% range in western districts and 30-
50% in eastern districts. This will follow fair to good overnight
recovery in western districts and good to excellent levels in eastern
districts. Winds speeds will remain seasonably light for the
majority of the period, albeit obtaining 20-30 mph northerly gusts
through the lower Colorado River valley late in the week. Increased
easterly winds will also be likely in eastern districts early next
week.

&&

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

$$

SHORT TERM...18
LONG TERM...18
AVIATION...Benedict
FIRE WEATHER...18