286
FXUS65 KTWC 160917
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
217 AM MST Tue Jul 16 2024

.SYNOPSIS...Temperatures slightly above normal through the rest
of this week, with typical mid July moisture levels across the
region. This will result in the daily chances for showers and
thunderstorms. The main threats will continue to be strong gusty
outflow winds and heavy rainfall leading to localized flash
flooding.

&&

.DISCUSSION...We still have ongoing convective activity early this
morning across far SW Cochise County and Santa Cruz County. This is
likely due to an MCV just south of the International Border. Latest
HRRR is struggling to pick up on this feature but do expect activity
to gradually diminish over the next couple of hours as it pushes
west. Meanwhile, for the rest of southeast Arizona, skies are clear
to partly cloudy and n o precipitation.

The broader pattern features the mid/upper level high near the Four
Corners region and this continues to result in easterly mid level
winds. Meanwhile, lower level flow will continue to slosh Gulf of
California moisture into the deserts. With that said, moisture
levels are fairly typical for this time of year with PWAT values
today around 1.25" to 1.50" from Tucson westward with some slightly
drier air hanging on for eastern areas as PWAT values are 0.75" to
1.25" east of Tucson. HREF/CAMs are pretty consistent in developing
scattered showers and thunderstorms this afternoon primarily across
Santa Cruz and Cochise Counties and another area on the White Mtns
and this will push to the west or west-southwest into the evening
hours. HREF members do tend to struggle holding convective activity
together as it pushes west of Tucson so we`ll have to see if that
holds up. With expected SBCAPE values over 1000 J/KG and DCAPE over
1500 J/KG, we`ll continue to have a hybrid severe threat for wind
and localized flash flooding threat in areas that see cell
mergers/clustering. SPC and WPC both have us in marginal risk areas
for thunderstorms and excessive rain, respectively.

The flow pattern remains similar on Wednesday. HREF members are
slightly less bullish Wednesday for convective coverage compared to
today but there isn`t a significant discernible difference in the
flow pattern or other convective parameters. Thereafter, not much
change for Thursday and Friday with continued daily rounds of shower
and thunderstorms. Expect typical variability in day-to-day trends
depending on smaller scale factors that aren`t identifiable this far
out. For this weekend into early next week, the high will shift a
bit more to the west and that will change our flow pattern to a more
northeasterly direction with increased chances of convection pushing
off the Mogollon Rim towards the lower elevations.

Temperatures through the period will remain several degrees above
normal.

&&

.AVIATION...Valid through 17/12Z.
BKN-OVC clouds 8-12k ft AGL near the International border including
KOLS will tend to diminish aft 16/12Z. Elsewhere, SKC-SCT clouds
this morning. SCT-BKN clouds redevelop again aft 16/18Z, with
diminishing cloud cover aft 17/05Z. SCT TSRA/SHRA thru 16/11Z,
mainly near KOLS. SCT TSRA/SHRA developing again for much of the
area aft 16/19Z. MVFR conditions in TSRA, with mountain
obscurations, vsby reductions and wind gusts to 40+ knots. Outside
of TSRA, SFC wind at most locations 12 knots or less favoring a SWLY
thru NWLY direction during the afternoon/early evening hours and
variable in direction at other times. The exception will be in the
upper Gila River valley near KSAD where WLY/NWLY SFC wind will be 15-
22 kts with gusts to 30 kts between 16/18Z and 17/03Z. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Deeper moisture remains across southeast Arizona,
with typical mid July moisture levels expected through at least the
upcoming weekend. This will result in the daily cycle of mainly
afternoon and evening showers and thunderstorms. The main threats
will be strong, gusty and erratic outflow winds and heavy rainfall
leading to localized flash flooding. Minimum relative humidity
values will be 20-30 percent in most lower elevation locations and
25-40 percent in mountain areas. Away from thunderstorms, 20-foot
winds will generally be 15 mph or less, with afternoon/early evening
gusts to 20-25 mph and light winds overnight. Wind direction will
primarily be southwest through northwest through most of the week.
The exception will be in the upper Gila River valley around Safford,
where afternoon/early evening winds will be west-northwest at 15-20
mph and gusts to 25-30 mph today.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$


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