935
FXUS65 KTWC 140839
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
139 AM MST Sun Jul 14 2024

.SYNOPSIS...Temperatures will fall back closer to seasonal
averages as high pressure weakens and deeper moisture returns to the
area. Thunderstorm coverage will ramp back up starting today and
continuing into the work week. Damaging thunderstorm winds will
continue to be a threat with some storms, along with heavy rain
threats gradually increasing through the week.

&&

.DISCUSSION...Latest IR/WV satellite imagery shows mostly clear to
partly cloudy skies from Tucson and points north and east and partly
to mostly cloudy skies to the south and west of Tucson. There is
currently a weakening MCS across northern Sonora that has resulted
in additional outflow induced convection over the past hour or two
across portions of the Tohono O`odham Nation and western Pima
County. This activity will diminish over the next couple of hours.

Broader pattern continues to feature mid/upper level high near the
Four Corners region with mid level easterly flow in place.
Meanwhile, in the lower levels, Gulf of California moisture aided by
the outflows from the Sonoran convection continues to stream into
portions of southeast Arizona, especially from Tucson and points
westward. This is reflected nicely in the surface dewpoint values
which are now in the 60s from Tucson westward. Considerably drier
air remains over much of Graham/Greenlee/Cochise Counties where PWAT
values range from 0.5" to 1". While the moisture profile today is
much more conducive for convective activity for the western half of
the forecast area and along the Int`l border, drier air will still
hold for eastern areas reducing convective potential there.
HREF/CAMs are focusing on areas along the Int`l border from Sierra
Vista westward, and especially Santa Cruz County into south central
Pima County for development of numerous showers and thunderstorms
with more scattered coverage around the Tucson Metro. With strong
inverted-v profiles and DCAPE values around 1500 J/KG, strong
outflow winds are going to be a concern today. Some localized flash
flooding also possible with the highest chances south and west of
Tucson where the deepest moisture resides. Given the propensity for
strong outflow winds, added blowing dust into the grids for much of
the T.O. Nation this afternoon into early evening.

For Monday, the Gulf moisture will continue to advect to the north
and east and that will set the stage for a potentially more
active/widespread convective afternoon/evening for much of southeast
Arizona. As the week progresses, the mid/upper level high will
meander a bit, but still be located to our north with favorable
easterly flow. Overall, it`s looking like a mid grade monsoon regime
for most of the week with the typical day to day variability that
will come into better focus as each day gets closer.

&&

.AVIATION...Valid through 15/12Z.
BKN-OVC clouds AOA 12k ft AGL mainly south to west of KTUS thru
14/12Z. Otherwise, SCT-BKN clouds at 8k-12k ft AGL are expected to
develop aft 14/18Z and continue thru 15/06Z before diminishing.
Isold/SCT TSRA/SHRA thru 14/11Z along the Int`l border west of
Tucson, and then again aft 14/19Z, mainly along the International
Border from KALK westward across Santa Cruz and central/western Pima
counties and also in the White Mountains. MVFR conditions in TSRA,
with mountain obscurations, vsby reductions and wind gusts to 40+
knots. Outside of TSRA, SFC wind less than 12 knots and variable in
direction thru 14/18Z, then WLY/NWLY at 8-15 kts with occasional
gusts to 22 kts between 14/18Z and 15/03Z, diminishing to less than
12 kts aft 15/03Z thru the end of the forecast period.  Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Moisture increases today and with typical
mid July moisture levels through the week, leading to an increase in
storm coverage and the potential for more widespread rainfall. Best
chances today are along the International border from Santa Cruz
County westward. Minimum relative humidity values in most lower
elevation locations in the 20-30 percent range and 25-45 percent in
mountain areas this week. 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 be west-
northwest through the middle of the week. Winds then switch to an
easterly direction late in the week.

&&

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

$$



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