836
FXUS65 KPSR 232005
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
105 PM MST Mon Mar 23 2026

.KEY MESSAGES...

- Unusually warm temperatures will continue to challenge daily
records through the week resulting in pockets of moderate HeatRisk.

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

- Temperatures should retreat from record levels early next week as
the weather pattern shifts away from stagnant high pressure.

&&

.SHORT TERM /Today through Wednesday/...
Longwave features over North American remain quasi-stationary this
afternoon with mean troughing over the east and ridging across the
west. While the amplitude of these features driving sensible weather
has decreased somewhat, the magnitude of the anomalies has only been
partially dampened. Over the local forecast area, robust positive
height anomalies continue with objective analysis indicating H5
heights around 586dm, and only recently reduced due to the proximity
of a cutoff low meandering off the northern Baja coast. All global
and high resolution output show midtropospheric anti-cyclonic
ridging re-intensifying over the next 48 hours such that H5 heights
near 590dm return to SE Arizona starting another warming cycle.
Ensemble guidance spread remains narrow yielding excellent forecast
confidence of high temperatures ~20F above normal, and breaking
records for the next several days. Due to more efficient nocturnal
cooling and limited magnitude of these afternoon readings, only
spotty and marginal moderate HeatRisk will be reached.

&&

.LONG TERM /Thursday through Sunday/...
The H5 ridge will remain the dominant feature over the Desert
Southwest through the weekend, keeping any noticeable relief out of
sight through at least the next 6 days. Once the thermal profile
fully catches up to the amplification of the ridge, widespread
triple digits will make their return to lower elevations during this
timeframe. Lower desert highs Thursday-Friday will range between 99-
103 degrees, continuing the record-trend for the forecast area. In
fact, current forecast 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 week is perhaps some
breezy conditions Thursday as the Baja trough 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-monsoon 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. Depending on the depth
of the moisture profile, it may also 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 as 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 this 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...18
LONG TERM...RW
AVIATION...Benedict
FIRE WEATHER...RW
CLIMATE...RW/18

NWS Phoenix (PSR) Office