276
FXUS65 KPSR 012010
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
110 PM MST Wed Oct 1 2025

.KEY MESSAGES...

- High pressure will continue to promote dry and quiet conditions
over the next few days

- Day-to-day temperatures will continue to slowly climb, peaking
Thursday with a few locations reaching into the triple digits.

- Low pressure will brush the Desert Southwest late this week and
into the weekend bringing breezy to locally windy conditions and
cooling temperatures.


&&

.SHORT TERM /TODAY THROUGH THURSDAY/...
Afternoon atmopsheric analysis reveals minimal change in the overall
pattern over the western CONUS with high pressure building over the
Desert Southwest and broad troughing over the Pacific Northwest and
northern Rockies. These two weather regimes are currently nudging at
each other for control over conditions across our forecast area, but
at least in the near term, the area of high pressure will win out,
staving off any advancement of the Pacific Low at least until the
end of the week. For us, that means more dry conditions and a
stepwise like uptrend in temperatures over the next few days.
Readings this afternoon across the lower deserts will be similar to
yesterday, with values generally in the middle 90s. As the high
amplifies further heading into Thursday, temperatures will tick up a
few degrees, with some locations seeing the return of triple digits.
It is not out of the ordinary to see the centrury mark on the
thermometer in early October (though if you look at last year, one
might think it is) as the average last triple digit day at Sky
Harbor at least is October 5th.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Ensemble and deterministic models remain in agreement that troughing
over the Pac NW will deepens over California and slide into the
Great Basin on Friday. As this occurs, 500 mb hghts will begin to
lower across the western half of the forecast area, but 500 mb hghts
will still hover around 588-590 dam over southcentral AZ. Negative
hght anomalies will arrive first in southeast CA Friday afternoon
where high temperatures will be slightly cooler in the low to mid
90s. However highs will still be above average in southcentral AZ in
the upper 90s to 100 degrees. Due to the tightening 700-500 mb hght
gradient, we will see a noticeable uptick in winds with breezy
conditions materializing across much of the region Friday afternoon.
The strongest winds (>30 mph) will likely reside across southeast
CA and the high country of northern AZ.

The trough axis will pass over N AZ on Saturday morning which will
drag a Pacific cold front through the forecast area. Post frontal
winds will continue to gust around 20-30 mph across southeast CA and
the Lower Colorado River valley early Saturday. 500 mb hghts will
lower back to seasonal ranges this weekend and into early next week,
which will foster temperatures cooling back to near normal Saturday
through early next week. Much drier air will also be ushered into
the region in the wake of this weather system which will allow
morning lows to feel much more fall-like in the low to mid 60s
across the lower deserts.

&&

.AVIATION...Updated at 1729Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Winds will continue to follow typical diurnal tendencies with
speeds aob 7 kt through most of the TAF period. Extended periods
of light and variable to calm winds are also expected. Skies will
continue to be clear.

Southeast California/Southwest Arizona including KIPL and KBLH:
At KIPL, winds will tend to favor a westerly component through the
TAF period with a period of light and variable winds this
afternoon and early evening. At KBLH, current light and variable
winds will go southerly this afternoon and then westerly to
southwesterly this evening. Speeds at both terminals will be aob 7
kt through most of the TAF period. Skies will continue to be
clear.

&&

.FIRE WEATHER...
Temperatures will climb above normal through the end of this week as
a ridge of high pressure strengthens over the forecast area. Expect
dry conditions to persist with MinRHs bottoming out each afternoon
around 25-35%. Overnight moisture recovery will generally remain
in the fair category around 40-60%. Winds will follow light and
diurnal tendencies through Thursday, however a weather system
passing north of the region will result in an uptick in breezy
conditions across the region on Friday. Expect gusts to increase
to around 20-25 mph region-wide with locally higher gusts upwards
of 30 mph both Friday and Saturday. The passage of this weather
system will also result in the arrival of cooler temperatures and
much drier air through this weekend.

&&

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

$$

SHORT TERM...RW
LONG TERM...Salerno
AVIATION...Berislavich/Benedict
FIRE WEATHER...Salerno

NWS Phoenix Office