Catalina Foothills, Arizona 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

861
FXUS65 KTWC 150109
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
609 PM MST Thu Aug 14 2025

.SYNOPSIS...Isolated chances for showers and thunderstorms
tonight, then chances increase on Friday with along with a risk
for flash flooding. Daily isolated to scattered shower and
thunderstorm chances into next week with day to day variability in
chances.

&&

.UPDATE...

At 600 PM MST this evening, convection was mainly contained to
central-western Pima county. Satellite imagery depicted an outflow
boundary moving westward into Ajo and Organ Pipe, though little
vertical cloud development was noted in this push and a westward
expansion of current activity looks unlikely in the near future.
To the east, the Tucson upper air observation this evening shows
little in the way of instability, while surface dew points in the
48-52 degree range signal diminishing chances for additional
shower/thunderstorm activity this evening. This forecast update
drops chances to the 20-30 percent range through early Friday
morning, as high-res models do still show the chance for isolated
activity.

&&

.PREV DISCUSSION... /issued 258 PM MST Thu Aug 14 2025/ There are
light showers with a few embedded stronger thunderstorms tracking
through Southeast Arizona. Areas south of Tucson, along the
International Border, have the better ingredients for storm
development compared to the rest of the region. Although, storm
life is short due to the mid level capping, a subsidence layer.
Still, we are getting into a more active monsoon pattern starting
with this afternoon.

A trough will be moving through the region which will flip our
flow to southwesterly from a light variable flow. This will bring
a better area of upper level dynamics for more organization of
thunderstorms and wetting rain showers. Especially when our PWATs
will be hovering around the 75th percentile for the next two
days. This deeper moisture will increase the risk of flash
flooding for the region. Looking at our 24 hour rainfall totals,
the latest NBM 24 hour QPF totals in Tucson has 0.13-0.78 inches
(the 25th-75th percentile range) with the median 0.35 inches and
Sierra Vista 0.34-1.12 inches (25th-75th percentile range) with
median 0.36 inches for Friday. A large range for those example
locations. The short term models are keying on the locally
heavier rainfall amounts, but they are differ on amounts and
locations because of today`s challenge to initialize correctly
with the morning MCV. That explains the spread of values from the
NBM, but we can expect heavier amounts on the mountains due to
upslope flow. There is a Slight Risk (15%) for flash flooding
areas south of Tucson to the International Border. In all,
Southeast Arizona will be in a more active pattern starting
tonight. There is growing confidence for late night convection and
showers tonight to the early Friday morning with the another
round of afternoon thunderstorms and rain showers.

By Saturday, chances for rain showers and thunderstorms will still be
elevated but a little lower than Friday`s. If there is enough
clearing in the late morning to afternoon, Southeast Arizona can
expect another active day. Otherwise, it will be generally downish
day with light showers and embedded thunderstorms. Pockets of
areas, mainly south and east of Tucson, will see the better
chances for any rain shower and thunderstorms.

Ahead into the new week, coverage and intensity will be trending
down. We will have lost our atmospheric moisture by Sunday,
staying slightly below normal. Temperatures will be increasing
above normal for the new week as the High starts to march towards
the Four Corners. This will shift the moisture back into the
region, providing better chances for rain showers and
thunderstorms by the second half of the week. This is something we
will keep an eye out. Stay tune.

&&

.AVIATION...valid through 16/00Z.
SCT-BKN clouds at 8-12k ft AGL with scattered -SHRA/-TSRA through
15/04Z. Lingering -SHRA is possible in the late night. By 15/10Z,
chances for -SHRA/-TSRA will return for areas near KTUS to KOLS
and then expanding across the region by 15/18Z. Although gusty and
erratic winds 35-40 kts will be possible near any TS, surface
winds should remain below 15 knots with the occasional afternoon
gusts up to 20 kts. Aviation discussion not updated for TAF
amendments.

&&

.FIRE WEATHER...Southeast Arizona will be in active monsoon
pattern starting tonight through Saturday with Friday being the
best chances for wetting rain showers and thunderstorms. After
Saturday, there will be daily chances for thunderstorms and
wetting rain showers into the start of the new week. Min RHs will
generally be around 25 percent in the lower elevations and 45+
percent in the mountains on Friday through Saturday. By Sunday,
min RHs will start to drop back down to the 15-20 percent in the
lower locations and 20-30 in the mountains into the new week.
Winds will generally be less than 15 mph with typical afternoon
gusts up to 20 mph into next week. Monsoon moisture is projected
to return late next week to provide higher chances for
thunderstorms and rain showers. Temperatures will be around normal
through Saturday and trend above normal through most of the new
week.

&&

&&

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

$$

Update...Edwards
Public...SN


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