285
FXUS65 KPSR 261147
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
447 AM MST Tue Aug 26 2025

.UPDATE...Updated 12Z Aviation Discussion.

&&

.KEY MESSAGES...

- Isolated showers and thunderstorms will remain possible through
  Wednesday with localized heavy rainfall still a possibility
  today.

- Near to below normal temperatures are forecast through Thursday
  with lower desert highs around 100 degrees.

- Drying conditions will mostly end rain chances by Friday as
  temperatures warm back to around or just above normal.

&&

.SHORT TERM /Today through Wednesday/...
After yesterday`s considerable monsoon activity, today is shaping
up to be much quieter. Moisture remains quite abundant across the
area with PWATs ranging from near 2" across southwest Arizona to
1.5-1.8" across the rest of the lower deserts. However,
yesterday`s widespread storms have effectively overturned the
atmosphere with temperatures currently in the 70s nearly
everywhere. Drier air aloft is also starting to work its way in
from the south. This dry air may help to allow for more sunshine
today, but given the cool start to the day we have a long way to
go to really destabilize the atmosphere enough to overcome the
CIN that has developed.

The current thinking is we should still see some morning isolated
elevated shower activity, but any afternoon convection is likely
to be fairly limited, especially in those areas that received
rainfall yesterday. Hi-res CAMs are mostly in agreement that
today should only see fairly sparse convection with the best
chances likely focused in southeast California and over eastern
Arizona. The ARW is showing more widespread shower and
thunderstorms by this afternoon, but this is most likely an
outlier. Any storms that do manage to develop today will still be
capable of producing heavy rainfall and some very localized
flooding due to the remaining decent moisture, but with less upper
level support and lower DCAPEs the threat for gusty winds will be
much less than yesterday.

Temperatures will be much more pleasant today, but given the
higher dew points it may feel more muggy than usual. Highs across
the lower deserts should only reach into the mid to upper 90s
today.

The drying conditions will continue on Wednesday with the flow
becoming more southwesterly and this should lower PWATs more into
a 1.2-1.4" range while mixing ratios drop to between 7-9 g/kg
across much of the area. This limited moisture should only allow
for some very isolated showers and weak thunderstorms focused
during the afternoon hours. Temperatures Wednesday are forecast to
warm a few degrees over today`s readings with highs topping out
right around 100 degrees for most lower desert locales.

&&

.LONG TERM /Thursday through Monday/...
Models have changed their tune slightly for Thursday as the upper
level remnants of TC Juliette are now expected to clip portions
of southern California. Due to the TC making it a bit farther
to the north, this may allow for a slight resurgence of moisture
into mostly southern California late Wednesday into Thursday. This
temporary boost in moisture should allow for a chance of showers
and a few isolated thunderstorms from Wednesday night through
Thursday night. The expected moisture will still be fairly limited
and should not pose a real threat for any additional heavy
rainfall, but PoPs have been increased to account for these rain
chances. Elsewhere on Thursday will likely see quiet conditions,
but much of Arizona may continue to see a good amount of
cloudiness.

By Friday and going into the weekend, the subtropical ridge
centered to our southeast will gradually impose more influence
across our region leading to a warming trend. However, forecast
H5 heights are only shown to be slightly above climatological
normals during this time which should keep our temperatures from
warming much above normals. Current NBM forecast highs show
readings between 102-105 degrees by Friday and mostly between
104-108 degrees for the weekend. These readings would put the bulk
of the area back into a Moderate HeatRisk for the weekend.
Looking out even further, guidance favors our flow turning more
south southeasterly as early as Monday of next week. If this were
to happen, we should see a gradual return of some monsoon moisture
and eventually some shower and thunderstorm chances again by the
middle of next week.

&&

.AVIATION...Updated at 1145Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Winds are expected to follow their typical diurnal tendencies
today, with speeds generally aob 10 kt. A few occasional gusts
into the teens is possible this afternoon. Current southeasterly
winds are expected to go westerly by 18-20Z today. SCT/BKN mid and
high level clouds will continue today. The one question mark for
today is the development of any TSRA this afternoon and early
evening. The atmosphere is pretty worked over after yesterday`s
storms, so confidence is too low (

NWS Phoenix Office