129
FXUS65 KPSR 231723
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1023 AM MST Mon Mar 23 2026

.UPDATE...Updated 18Z Aviation Discussion.

&&

.KEY MESSAGES...

- After a brief "cooldown" to start off this week, widespread
  triple digits return to the lower deserts by Wednesday.

- Afternoon temperatures will remain near or above record levels
  potentially into the start of the upcoming weekend.

- The unseasonably hot conditions will be dangerous, especially
  with any strenuous or long-duration outdoor activities without
  proper hydration and frequent breaks in the shade, or air
  conditioning.

&&

.SHORT TERM /TODAY THROUGH TUESDAY/...
Generally zonal flow continues to stretch across the western CONUS,
while a concentrated cut-off low meanders off the Baja Coast. This
flat pattern is thanks to a series of shortwaves over southern
Canada and the Gulf of Alaska nudging at the record-setting ridge,
displacing the center of this feature further to our south. With
lower heights, indicating at least a relatively cooler atmospheric
profile, temperatures this afternoon and Tuesday will be a few
degrees cooler compares to what was seen on Sunday, with highs
mainly in the middle to upper 90s. This is still 15-20 degrees
warmer compared to where the region should be this of year, and
new daily record highs are likely to continue to be met or
exceeded for many locations during this timeframe.

The stubborn ridge will not give up so easily and is expected to
restrengthen over the region once again by Tuesday. H5 heights will
climb once again toward 588-590dm, putting the ridge back into
climatological record territory for this time of year.
Temperatures will rise slightly in response to this reinforcement
of the high, but widespread triple digits will take a slightly
longer to return as the thermal profile lags behind.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
The ridge will remain the dominant feature over the Desert Southwest
through the middle portion of the week and into the weekend, keeping
any noticeable relief out of sight through at least the next 5-6
days. As alluded to above, once the thermal profile fully catches
up to the amplification of the ridge, widespread triple digits
will likely make their return during this timeframe. Lower desert
highs Wednesday-Friday will range between 99-103 degrees,
continuing the record-trend for our forecast area. In fact, the
current forecasted highs for Phoenix Sky Harbor would break each
daily record high from now until Saturday. Having already eclipsed
five consecutive daily records, it appears likely that this
streak will reach at least 11 days before all is said and done.
The only noticeable weather change projected during the workweek
is perhaps some breezy conditions Wednesday and Thursday as the
trough that is currently off to our southwest cycles around the
periphery of high`s center before ejecting over the Great Basin.

Not to get everyone`s hopes up, but there may be at least some
relief on the near horizon. Global ensembles are in decent agreement
regarding the center of the ridge migrating eastward toward the
Plains by the weekend, imparting southerly flow over the region.
This would set up a quasi-monsoonal pattern as the southerly flow
would tap into sub- tropical moisture, potentially pushing PWATs
toward 200-250% of normal. This would, at a minimum, push
considerable cloud cover overhead, limiting diurnal heating
resulting in relatively cooler temperatures. It may also,
depending on how deep the moisture profile can be, create a
favorable environment for showers and thunderstorms for parts of
the forecast area. As of now, any rain potential is focused over
the high terrain of eastern Arizona has orographic influences
create a better setup for precipitation. The overall synoptic lift
profile doesn`t look all that promising currently, so any
rainfall coverage would likely be limited, but a fair amount of
uncertainty remains so this will be something to keep an eye on in
the coming days.

&&

.AVIATION...Updated at 1721Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No aviation weather concerns are expected through Tuesday under
occasional passing high clouds. Winds will continue to follow
familiar diurnal tendencies with speeds AOB 10 kts. E/SE winds
this morning will shift to a predominant westerly component by
19-21Z, with a period of southerly variability favored during the
transition. Winds Tuesday will be nearly identical to today.

Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation weather concerns expected through Tuesday under
occasional high clouds. At KIPL, southeast winds will prevail. At
KBLH, winds will favor S to SSW. Overall wind speeds will
generally fluctuate between 8-12 kts. Periods of calm and light
variability can be expected during the morning hours at both
terminals.

&&

.FIRE WEATHER...
Record heat along with dry conditions will persist through this
week. MinRHs will generally range between 5-10%, with portions of
the western districts being the exception during the next few
afternoons, as an increase in Gulf of California moisture will
push MinRH values for these areas closer to 15-20%. MaxRH values
will follow a similar pattern with readings generally between
20-40% for the eastern districts as higher readings closer to
50-70% are observed for western districts locales the next couple
of mornings. Winds will be generally light and follow diurnal
trends with typical afternoon upslope breeziness through Wednesday.
More widespread and stronger gusts may come into play during the
latter portion of the week and into the weekend. With very dry
air in place, any stronger winds would result in periods of
elevated fire weather conditions.

&&

.CLIMATE...

Daily record highs through the upcoming work week:

Date      Phoenix         Yuma         El Centro
----      -------         ----         ---------
3/23     93 in 1990     96 in 1990     93 in 1990
3/24     96 in 2025     97 in 2025     96 in 2025
3/25     99 in 2025     99 in 1896     99 in 2025
3/26    100 in 1988     99 in 1988     98 in 1988
3/27     98 in 1986    100 in 1986     99 in 1988
3/28     95 in 2015     98 in 2015     98 in 2015

&&

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

$$

SHORT TERM...RW
LONG TERM...RW
AVIATION...Benedict/Lojero
FIRE WEATHER...RW
CLIMATE...RW/18

NWS Phoenix (PSR) Office