Tempe, Arizona Weather Forecast Discussion

683
FXUS65 KPSR 142324
AFDPSR
Area Forecast Discussion
National Weather Service Phoenix AZ
424 PM MST Sun Sep 14 2025
.UPDATE...Updated Aviation Discussion...
&&
.KEY MESSAGES...
- Near to slightly below-average temperatures today before gradually
warming through the middle of the work week.
- No showers or storms expected today through the first half of  the
week, with mostly sunny skies and light winds.
- Potential for a widespread rain event late week into next weekend
with a push of moisture, but there is still a high degree of
variability with this forecast.
&&
.SHORT TERM /TODAY THROUGH MONDAY/...
Water vapor satellite imagery early this afternoon shows westerly
flow aloft and an abundance of dry air across the region that was
brought in from the trough that moved through over the past
couple of days, which is now in the Plains. The abundance of dry
air is also present on the SPC mesoanalysis, where PWAT values are
around 0.5" or less across much of the region. Objective analysis
also shows weak troughing over the area with a shortwave in
central CA and another shortwave over Sonora, Mexico. TC Mario and
another tropical wave are just off the west coast of Mexico,
which will need to be watched as their track could play a role in
our weather for the end of the week and next weekend. There is
also a subtropical high over central Mexico, which will play a
role in our weather over the next couple of days as it builds into
our region.
With the dry conditions in place, shower and storm chances will
continue to be around 0% across the region through at least
tomorrow. As previously mentioned, the subtropical ridge will be
building into our region which will allow for a gradual warming of
temperatures. Temperatures early this afternoon are a couple degrees
warmer than they were at this time yesterday and are also forecasted
to top out a few degrees warmer than yesterday. Most lower desert
locations are forecasted to see highs in the upper 90s to near 100
degrees today with higher terrain areas in the upper 80s to low 90s.
Further warming is expected tomorrow as the high builds further into
our area, with afternoon high temperatures forecasted to be near to
slightly above normal (100-105 degrees across the lower deserts and
in the 90s in the higher terrain). The dry conditions and clear
skies will continue to allow for temperatures to cool off rather
nicely for the overnight and early morning period. Early morning
lows will continue to be pleasant with Monday morning lows
forecasted to be a couple degrees warmer than this morning, but
still in the 70s across the lower deserts and in the 60s in the
higher terrain. Keep practicing smart heat safety in the afternoons
as long exposure to 90+ degree heat can still have negative health
impacts without the proper heat safety actions.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
Forecast confidence through the first half of this coming work
week remains high. High pressure will continue to nudge into the
region, leading to a gradual rise in 500mb heights. Global
ensembles have H5 heights peak around 590dam on Tuesday, which is
around 80th percentile of climatology for this time of year. As a
result surface temperatures will climb slightly above normal for
at least Tuesday and Wednesday. Latest NBM forecast has afternoon
highs reaching 101-105 degrees both days. There will be a slow
return of moisture through Wednesday, enough for some clouds to
develop, but likely not enough still for showers or storms in
South-Central AZ to Southeast CA. Latest NBM PoPs are at 

NWS PSR Office Area Forecast Discussion