332
FXUS65 KPSR 130515
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
1015 PM MST Mon Aug 12 2024

.Update...06Z Aviation Discussion

&&

.SYNOPSIS...
Showers and storms will be again be possible this afternoon and
evening, but activity will mainly favor the higher terrain
locations. Drier air will work it`s way into the region for the
middle of the week causing a significant downtrend in monsoon
activity. Moisture looks to rebound slightly by the end of the
workweek and heading into the weekend leading to storm chances
returning to the region, mainly for the higher terrain locations.
Temperatures will remain largely unchanged through the week and run
slightly above normal.

&&

.DISCUSSION...
An overall pattern change expected this week as the Monsoon
pattern gets displaced with a drier westerly flow. Best chance
for storms this week will be into this evening as moisture and
instability remains in place for one more day. Environment
continues to support convection with MUCAPES 1000-1500 and
weakening inhibition. Latest Hi-Res, continues the focus on the
higher terrain and into SE AZ with initiation. Depending on the
magnitude of the convection in SE AZ, that could play a role in
an outflow heading northwest across the valley and be a trigger
for isolated storms, but coverage will be 10-20 percent.

Otherwise, current troughing across the Pacific Northwest moving
into the northern Rockies will begin to flatten upper heights in
our region, making that transition from a moist southerly flow to
a dry west/northwest flow by the middle of the week. Some
lingering storms in the eastern 3rd of AZ for Tuesday, but dry
conditions look to settle in for Wed/Thu as ridge axis shifts to
the south of the area cutting off moisture. Precipitable waters of
0.8-1.2" in most areas, unfavorable for storm development.

By Friday and into the weekend, the upper flow becomes more
amplified with deeper trough digging off the west coast and
strengthening High to our east across NM/TX. This will return a
south/southeast flow, moisture and our daily storm chances,
especially for those favored higher elevation locations.

Temperatures this coming week are forecasted to remain largely
unchanged. For the lower desert communities, afternoon high
temperatures are forecasted to be in the 100-110 degree range
through the week. For the higher terrain areas, afternoon high
temperatures are forecasted to be in the 90-100 degree range.
With temperatures being near to slightly above normal, HeatRisk
will be in the Minor to Moderate range across the region.

&&

.AVIATION...Updated at 0515Z.

South Central Arizona including KPHX, KIWA, KSDL, and KDVT:
No aviation concerns are expected during the next TAF period.
Winds will follow typical diurnal trends, with occasional gusts
during the afternoon hours near 15-20 kts. Shower and thunderstorm
activity will once again initiate over the usual areas tomorrow
afternoon but chances of in the vicinity of the terminals during
that timeframe is less than 5%. Chances of distant outflows
impacting the terminals are also minimal (~10%). SCT mid and high
level clouds will diminish in coverage overnight, with just a FEW
low-level clouds prevailing through the remainder of the period.

Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation concerns are expected during the TAF period. Winds
will follow familiar diurnal trends, with occasional gusts near 20
kts during the afternoon and evening hours. Mostly clear skies
will prevail during the next 24 hours.

&&

.FIRE WEATHER...
Shower and thunderstorms chances will continue today, with the best
chances confined to the higher terrain locations. Shower and
thunderstorm chances tomorrow will be limited to just the higher
terrain locations. With any thunderstorm activity, there will be
strong winds along with the potential for gusty outflows to travel
long distances and cause sudden wind shifts. Thunderstorms will also
contain localized heavy downpours and frequent lightning. Drier air
will move into the region for Wednesday and Thursday with little to
no thunderstorm activity expected. Aside from thunderstorm winds,
the overall general winds will tend to follow their typical diurnal
tendencies with some afternoon upslope breeziness. MinRH values
today will be in the 20-30% range with a downward trend for the
middle of the week with MinRH values in the 10-25% range. Overnight
recoveries will be in the 30-50% range. Temperatures though the week
will remain largely unchanged and run near to slightly above normal.

&&

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

$$

DISCUSSION...Frieders
AVIATION...RW
FIRE WEATHER...Berislavich/Frieders