085
FXUS65 KPSR 152331
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
Issued by National Weather Service Tucson AZ
431 PM MST Mon Dec 15 2025

.UPDATE...Updated 00Z Aviation Discussion.

.KEY MESSAGES...

- Well above normal temperatures and dry weather will prevail
  across the entire region for the remainder of this week.

- Record setting highs will be possible across the lower deserts
  today, including Phoenix.

&&

.SHORT TERM /TODAY THROUGH WEDNESDAY/...
Latest mid-lvl water vapor imagery and 500mb streamline analysis
reveals a dry and weak area of low pressure progressing through
AZ which is embedded in a larger scale ridging pattern across
much of the western and central U.S. This disturbance did bring
some high clouds to southcentral AZ this morning, but skies have
since cleared, allowing for temperatures to rise well above
normal again this afternoon. Temperatures have already reached
the upper 70s to 80 degrees across the lower deserts and are
expected to reach record territory again in Phoenix this
afternoon. The projected high of 81 degrees at Sky Harbor is
expected to break the previous record of 79 degrees last set in
1969. Elsewhere across the forecast area, high temperature records
will be threatened. In the wake of the passing shortwave trough
today, temperatures will cool by a couple of degrees, mainly
staying below 80 degrees on Tuesday and Wednesday. However, these
highs will still be on the order of 10-15 degrees above normal.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
The eastern Pacific ridge off the coast of southern California and
northern Mexico is forecast to strengthen again over the next
couple of days as it gradually shifts eastward toward our region.
By Thursday into Friday, a weather system should be exiting the
Northern Rockies into the Northern and Central Plains allowing the
ridge to our west to move more into our region. As a result,
ensemble mean H5 heights are shown to increase again closer to
585dm by Thursday or well into the 90th percentile of climatology.
This should push our temperatures upward again with some lower 80s
likely possible on Friday. Models do still keep the center of the
ridge off the Baja coast Friday into next weekend, but the ridge
will still remain dominant over the Desert Southwest through at
least the coming weekend providing continued dry and tranquil
weather conditions. This may eventually come to an end later next
week as guidance still supports a trough setting up off the West
Coast by Christmas.

&&

.AVIATION...Updated at 2330Z.

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

No aviation weather concerns will exist through the TAF period.
Winds at the Phoenix Metro terminals NW then become light and
vbl at or below 10 kts overnight. At the SE California TAF sites,
winds will primarily be out of the N-NW at KBLH and W-NW at KIPL.
Skies will remain mostly clear through Tuesday morning.

&&

.FIRE WEATHER...
Persistent high pressure across the region will result in warm
and dry conditions all week. Highs in the upper 70s to the lower
80s will be common across the lower deserts, or 10 to 15 degrees
above daily normals. Winds will overall be light and follow
familiar diurnal patterns. MinRHs will range from 15-25% while
overnight recoveries will generally remain fair up to 40-70%.

&&

.CLIMATE...Daily Record Highs

   Phoenix
   -------
12/15   79 (1969)

&&

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

$$

SHORT TERM...Salerno
LONG TERM...Kuhlman
AVIATION...JT
FIRE WEATHER...Salerno/Kuhlman
CLIMATE...Benedict