Area Forecast Discussion
Issued by NWS Phoenix, AZ

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FXUS65 KPSR 100216

Area Forecast Discussion
National Weather Service Phoenix AZ
716 PM MST Fri Jun 9 2023

.UPDATE...Updated Aviation discussion.


Dry weather conditions will persist through the next several
days. Below normal temperatures will continue through the first
half of next week before a warming trend pushes readings back to
near normal by late next week. A weather disturbance moving across
the region during the upcoming weekend will likely result in
enhanced breeziness, with the most widespread breeziness expected
on Sunday.


Latest water vapor satellite imagery shows a weakening upper-level
low pressure over the Great Basin with a quasi-zonal flow enveloping
most of the region. As a result, temperatures through Saturday will
be slightly warmer than they were earlier this week, with highs
mostly in mid to upper 90s, which will still be below normal for
this time of the year. Phoenix may still see a return to
temperatures reaching 100 degrees on Saturday, with the latest NBM
probabilities at now greater than 50% chance for occurrence. In
addition, to the below normal high temperatures, given the dry
conditions in place, overnight lows will also be below normal with
readings ranging from the mid 60s to lower 70s. This will
maintain the HeatRisk at minor levels, nevertheless the necessary
heat precautions should be taken if planning outdoor activities
for an extended period of time.

The next low pressure system, currently located off the west coast,
will be moving into California by Saturday night and through the
Great Basin through early next week. As it does so, a cooling trend
will ensue, especially Sunday and Monday, when high temperatures
across most of the lower desert communities only reach the lower to
middle 90s. These temperature readings will be nearly 10 degrees
below normal for this time of the year. In fact, there is a
greater than 50% chance according to the latest NBM that portions
of the lower deserts of southeast California, including the
Imperial Valley, fail to reach 90 degrees. In addition to the cool
down, the pressure gradient will be tightening ahead of the
approaching low pressure system. Gusty winds will be confined
mainly across western Imperial County on Saturday evening, where
mountain rotors will likely result in gusts in excess of 35-40
mph. The gusty winds will be become more widespread on Sunday,
when south-central Arizona will likely see gusts ranging between
25-30 mph. Lastly, enough forcing and moisture may be present to
result in a couple of showers early Sunday across northwestern
portions of Joshua Tree National Park, with NBM PoPs currently
sitting at between 20-40%.

Ensembles are in good agreement that the aforementioned low pressure
system will be exiting out of the region towards the northeast while
weakening in the process through the middle of the week. As it
does so, high pressure aloft will be building over central Mexico
and into the southern Plains, which will help raise the heights
aloft over portions of the southwestern CONUS. This will result in
a warming trend through the end of next week with temperatures at
least returning back to near normal. There is quite a bit
discrepancy amongst the ensembles as to how far west and north
the high pressure will build. This will be key in determining
whether or not the region warms even further to possibly above
normal levels, which could signify temperatures nearing 110
degrees by the weekend of June 17-18.


.AVIATION...Updated at 0215Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Westerly winds will subside this evening, followed by the onset
of drainage flow around 08z-11z. Winds Saturday will follow a
similar evolution to those the past few days with a gradual
veering through the day. A 2-3 hour period of southerly winds is
(70%) likely before the westerly flow becomes established during
the afternoon. Meanwhile, the pressure gradient will tighten
during the afternoon as an area of low pressure drifts towards the
southern California coast. Wind gusts up to 25 kt are (50%)
possible Saturday evening before subsiding Saturday night.

Southeast California/Southwest Arizona including KIPL and KBLH:
At KIPL, southeasterly winds are expected to switch to westerly
overnight and then become light and variable Saturday morning. The
westerly flow is expected to redevelop Saturday evening with
gusts as high as 30-35 kt. At KBLH, southwesterly winds will
persist overnight before shifting to the south and weakening early
Saturday morning. Breezy conditions are expected Saturday
afternoon and early evening with peak gusts likely reaching 20-25


Dry conditions with below normal temperatures will prevail for the
next several days. Winds will favor typical diurnal tendencies,
with occasional afternoon gusts near 20 mph. Winds are expected
to increase this weekend ahead of another low pressure system,
which could lead to elevated fire weather conditions, especially
on Sunday when the most widespread breeziness is expected. Lighter
winds are anticipated next week. MinRH values during the next
several days will generally remain below 15% across most areas
with minimal to modest overnight recovery.


.HYDROLOGY...Updated 255 PM MST 6/6/2023

GILA: Releases from Painted Rock Dam continue to remain above 1,000
cfs, leading to extended downstream impacts along the Gila River.
Impacts include continued inundation of unbridged river crossings,
with many of these remaining closed. Therefore, the Flood Warnings
along the Gila River between Painted Rock Dam and the Colorado River
have been extended through June 13th.




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