405
FXUS65 KPSR 191016
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
316 AM MST Sat Sep 19 2026

.KEY MESSAGES...

- Dry and tranquil weather conditions with near zero rain chances
  can be expected through Monday.

- Near to slightly above normal temperatures will persist through
  next week.

- A low pressure system and moisture return early next week will
  bring a return of rain chances to at least the high terrain of
  northern and eastern Arizona.

&&

.SHORT TERM /TODAY THROUGH SUNDAY/...
Upper-level water vapor satellite imagery early this morning shows a
low pressure system in the northern Great Basin and a high pressure
system centered over eastern Texas. In between these two features
there is dry southwesterly flow over the Southwest. With dry
southwesterly flow still in place over our region moisture continues
to decrease. PWATs have decreased another 0.1-0.3" from yesterday
afternoon with PWATs currently ranging from around 0.4" across
the western deserts increasing to around 0.8" across the higher
terrain areas in southern Gila County. Dry southwesterly flow will
continue across the region today before going more westerly
tomorrow as the aforementioned low pressure system moves eastward
into the northern Plains. As the drying continues PWATs are
expected to bottom out late tonight around 0.3-0.6". We will
finally see this drier air make its way to the surface today as
dew points fall into the 30s and 40s by late this afternoon/early
this evening. There will be some moisture return from the Gulf of
California into far SW AZ and SE CA tomorrow with dew points going
back into the 50s for them, otherwise dew points will generally
be in the 40s for most other locations. Due to all the dry air
across our region this weekend, there will be mostly clear skies
with zero chances for showers or storms. Additionally H5 heights
will remain largely unchanged (generally around 588 dm), so
temperatures will also remain fairly steady through the weekend.
Afternoon highs will be in the upper 90s to low 100s (upper 80s to
mid 90s) with morning lows in the 70s to around 80 degrees (mid
60s to low 70s) across the lower deserts (higher terrain). This
will result in widespread Minor HeatRisk across the CWA.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Models are in good agreement that a Pacific low will move to the
south-central coast of California by early Monday and then move
eastward onshore throughout the day. If it weren`t for the lack of
moisture on Monday it would be a decent set up for a transitional
severe weather event as there will be potential for some
frontogenesis with upper-level jet support and higher shear.
However, while PWATs will increase on Monday, they look to remain
around or slightly below 1" (0.6-1.0").

Then on Tuesday the low will slowly weaken as it moves NE into NV/UT
before getting swept up into the large scale flow on Wednesday as it
moves into the northern Plains. At the same time a weak ridge will
be in place over TX and will start to strengthen on Wednesday. This
will result in southwesterly flow over our area. With the moisture
return and some upper-level forcing from the aforementioned low,
rain chances will return to the higher terrain areas in northern
and eastern Arizona. Weak large scale troughing will remain
across the eastern Pacific/West Coast through the end of next week
and will be battling the ridge of high pressure over TX. By the
end of the workweek the ridge will try to retrograde into NM/AZ.
Additionally ensemble members bring a surge of moisture into our
area from the SE pushing PWATs back into a 1.0-1.3" range. As a
result NBM/WPC PoPs for the end of next week have 30-50% chance
of showers and storms across the higher terrain in southern Gila
County and around 10-20% across the lower deserts of south-central
AZ.

Temperatures next week will remain largely unchanged and be in the
upper 90s to low 100s across the lower deserts and in the upper 80s
to mid 90s across the higher terrain. Morning lows will generally be
in the 70s to to low 80s across the lower deserts and in the 60s
across the higher terrain areas. Morning lows do look to start to
creep up by the end of next week (more morning lows in the low 80s
across the lower deserts). As a result widespread Minor HeatRisk
will continue through the beginning of next week with Moderate
HeatRisk returning to the lower deserts for the latter half of next
week as the morning lows creep up and daily normals decrease.

&&

.AVIATION...Updated at 1015Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No aviation weather concerns expected through Sunday morning under
clear skies. Winds will continue to follow typical diurnal
tendencies with speeds around 8 kts or less. There will likely be
a period of light southerly cross-runway winds at KPHX for most of
the afternoon ahead of prevailing W-SW winds by late
afternoon/evening. Extended periods of calm and vrb conditions
can also be anticipated during the overnight and morning periods.

Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation weather concerns expected through Saturday night under
mostly clear skies. Winds will follow seasonal diurnal patterns at
both terminals with mainly a W component at KIPL and S-SW at KBLH.
Wnd speeds should remain around 8 kts or less with limited gusts,
and extended periods calm conditions to light vrb can be expected.

&&

.FIRE WEATHER...
Overall there are no fire weather concerns through the next week.
Conditions will continue to dry out today with no chances for rain
continuing through Monday. Slight chances for showers and storms
return to the higher terrain areas of southern Gila County
beginning on Tuesday. MinRHs will be around 10-25% today and
tomorrow before increasing to around 15-30% for the first half of
next week. Overnight recoveries will range from fair to good
across the region through the middle of next week. Besides a
potential increase in breeziness early next week with a weather
system, winds will mostly follow typical diurnal patterns with
modest afternoon upslope/upvalley gustiness (15-25 mph).

&&

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

$$

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