309
FXUS65 KPSR 191124
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
424 AM MST Sat Apr 19 2025

.UPDATE...Updated 12Z Aviation Discussion.

&&

.SYNOPSIS...
Weak high pressure and drier conditions will build back into the
region this weekend with below normal temperatures today warming
into the normal range on Sunday. Tranquil weather conditions under
clear to mostly clear skies are expected through at least the
first half of next week with temperatures running a few degrees
above normal.

&&

.DISCUSSION...
A rather robust and compact upper level low is currently tracking
through the area with the low center near Flagstaff and a cold
front now pushing through southeast Arizona. This system ended up
being better organized than advertised bringing widespread
rainfall amounts of around 0.1" to the south-central Arizona lower
deserts to upwards of 0.3-0.5" to portions of the higher terrain
north and northeast of Phoenix. The main precip band has mostly
exited our area and should do so completely over the next hour or
two. As the low center tracks into western New Mexico later this
morning, the drier air will completely fill in across southeast
California and southwest Arizona before doing so across the rest
of Arizona by this evening. There may be a few additional
afternoon showers over the eastern Arizona high terrain today, but
areas from Globe westward will see generally clear skies and
high temperatures mostly in the 70s.

For Sunday and well into next week the weather pattern will keep a
quasi-zonal southern jet branch well to our south and the
northern more active jet branch mostly across the northern tier
states. The Desert Southwest will stay in between the two jet
branches with broad troughing to quasi-zonal flow persisting
through at least mid week. H5 heights over our region will quickly
recover by Sunday leading to noticeable warming and highs back
into the normal range before topping out a few degrees above
normal in the upper 80s to the lower 90s starting Monday. With
little change in the upper level pattern and dry conditions
prevailing, temperatures will be quite stable for most if not all
of next week. Ensemble guidance does eventually try to build a
deeper trough off the West Coast later next week, but its eventual
track is likely to stay well north of our region. For now, the
biggest impact from this next trough will be a modest increase in
winds later this week.

&&

.AVIATION...Updated at 1122Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
After the passing of last night showers winds are expected to be
VRB until establishing a more dominant westerly component by late
this morning, with KIWA more NW. Another round of VRB conditions
will be common starting tonight into the overnight periods, with
KPHX expected to have a late easterly shift (~08Z). Wind speeds
will generally be aob 10 kt. Ceilings will lift and scatter out
over the next couple of hours and becoming progressively clearer
throughout the morning.

Southeast California/Southwest Arizona including KIPL and KBLH:
At KIPL, W/NW winds will go northerly around 16Z with speeds
generally aob 10 kt. Winds at KBLH will be out of the north with
speeds generally aob 10 kt, with the exception of some gusts up
around 20 kt from the mid morning through the mid afternoon. Winds
will become light and variable at both TAF sites this evening.
Skies are to remain clear for the TAF period.

&&

.FIRE WEATHER...
A weather system will exit the region today leaving behind drying
conditions and a return to tranquil weather. Temperatures will
gradually warm into early next week stabilizing at a few degrees
above normal starting Monday. MinRH values will fall throughout
the weekend with values lowering to around 10% across the western
districts today and then areawide starting Sunday. Lighter winds
are also anticipated starting today for most areas, but expect
breezy conditions across the Lower CO River Valley this morning
before diminishing during the afternoon. The quiet weather
conditions are likely to persist through at least mid week with
seasonably dry conditions and relatively light winds each day.

&&

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

$$


DISCUSSION...Kuhlman
AVIATION...Ryan
FIRE WEATHER...Kuhlman