784
FXUS65 KPSR 081107
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
405 AM MST Sun Mar 8 2026

.UPDATE...
Updated Aviation

&&

.KEY MESSAGES...

- Breezy conditions will linger this morning in southeast California.

- A weather system will pass just south of the area early this week
increasing chances for showers and potentially some thunderstorms.

- High pressure returns midweek, allowing temperatures to warm back
into a well above normal category with lower desert highs likely
reaching the nineties by Thursday.

&&

.SHORT TERM /TODAY THROUGH TUESDAY/...
Midlevel water vapor imagery and 500 mb RAP analysis show the core
of the cut-off low, that fully developed yesterday, now positioned
off the Western coast of Northern Baja. Ensembles remain in good
agreement that the upper low will stay far enough to the southwest
today so that positive midlevel height anomalies will fill back in
over the region. In response, afternoon highs today will ramp up
into the mid to upper 80s across the lower deserts and even into the
mid to upper 70s in the higher terrains. Temperatures in this range
will be generally 10-13 degrees above normal in South-Central AZ and
6-10F above normal across the western deserts. Temperatures will
cool by Monday and Tuesday as the low progresses and is expected to
bring some isolated to scattered showers. Monday and Tuesday`s high
temperature across the lower deserts will be in the mid to upper 70s
with localized areas in the low 80s.

The low will begin slowing moving eastwards starting Monday
afternoon across Northern Mexico/Southern Arizona and is expected to
be to the region`s east by Tuesday afternoon. This will lead to
moisture advection into the region with PWAT anomalies reaching 180-
220% of normal during this time. Over the past few model runs both
PoPs and QPF totals continue to trend upwards, with the
precipitation chances (30-45%) starting Monday morning in SE CA/SW
AZ. However the best time and areas for precipitation will be Monday
evening over South- Central AZ (50-65%), and Eastern AZ into the
higher terrain areas (70-80%). In conjunction to PoPs, as the low
progresses the threat of thunderstorms will be possible Monday
evening into the early Tuesday morning as MUCAPE ensemble means are
between 200-500 J/kg. With these thunderstorms, small hail will
possible, with 500 mb temperatures in a -20C to -25C range and
decent instability in the hail growth zone. While, confidence in
PoPs have grown, uncertainty remains in the exact locations of the
activity, as showers are expected to be isolated to scattered. Even
though some areas may not receive any rainfall, the average QPFs
totals across South-Central AZ are between 0.10-0.25" and Eastern
AZ/higher terrain between 0.25-0.40".

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
By Wednesday the cut-off low will be well into Western Texas,
allowing upper level ridging to develop over the Desert SW. Mid to
late week temperatures will return to well above normal resulting in
area wide Minor HeatRisk. During this time H5 heights are expected
to be above the 90th percentile of climatological normal. The lower
deserts on Wednesday will climb back into the low to mid 80s. The
remainder of the week will continue to warm into the low to mid 90s.
This will result in multiple days with the potential for new record
highs in Phoenix, with Friday having a 95% chance of surpassing the
previous record high of 92 degrees set in 2017.

&&

.AVIATION...Updated at 1105Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Erratic wind directions and odd timing of wind shifts will be the
primary weather concerns through Monday morning under increasing
mid/high cloud decks. While E/NE winds will be preferred through
much of the day, some erratic directions (albeit with very light
speeds) through mid morning will be common. A few brief gusts will
be possible late morning/early afternoon, but likely very limited in
time and space. Confidence is good that SW winds will sweep into the
metro mid/late evening, though timing and expanse of this wind shift
carries lower forecast confidence.


Southeast California/Southwest Arizona including KIPL and KBLH:
No major weather issues will exist through Monday morning under
increasing mid/high cloud decks. Confidence is moderate that winds
will generally veer from a NW direction to more NE through the day,
then likely obtain some variability overnight. Gusts should be
mostly absent this period.

&&

.FIRE WEATHER...
Dry conditions will persist today across the region with minimum
relative humidity values staying entrenched between 10-15%.
Lingering breezy conditions across southeast California and over
higher elevations will continue through this morning, leading to
locally elevated fire weather concerns before slight increase in
moisture arrives Monday. Monday`s weather system will help increase
MinRHs to between 30-40% with good overnight recoveries before
returning to drier conditions by the middle of the week.

&&

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

&&

$$

SHORT TERM...Ryan/Whittock
LONG TERM...Ryan
AVIATION...18
FIRE WEATHER...Ryan/Whittock