597
FXUS65 KTWC 050920
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
220 AM MST Sat Jul 5 2025

.SYNOPSIS...Isolated to scattered storm coverage focused on
locales south of Tucson. Temperatures warming back up to above
normal levels this weekend then getting hotter next week.

&&

.DISCUSSION...For those still following the start of the monsoon
via the average daily dewpoint of 54 degrees or greater in
Tucson, July 2 is your start date.

Satellite imagery this morning showed a plume of mainly mid-level
clouds streaming over the area under SW flow aloft. These clouds
extend well to the SW to the remnant circulation of what was
Hurricane Flossie, which was located around 325 miles SW of the
Baja Spur. Per WPC precipitable water (PW) 12 hour change imagery,
PW values over Pima/Santa Cruz counties are possibly up around
0.30". Can`t tell what the actual values are on GOES-19 imagery
due to cloud cover but I`m guessing values in the 1.25" to 1.50"
range. Sure would be nice to have a 12z Tucson sounding but will
have to wait until 18z. Surface dewpoints at 2 am were in the 60s
across Pima, Santa Cruz and SW Cochise.

For today: Per the CAMs the best area for storms this afternoon
would be from SW Cochise county west across Santa Cruz county to
Sells. Main threat will be outflow gusts to 45 mph and brief
heavy rain and localized flash flooding. Highs will run a few
degrees warmer than yesterday.

Sunday: All guidance is pointing to Santa Cruz and Cochise
counties having the best chances for afternoon/evening storms as
the high builds overhead resulting in highs 3 to 6 degrees hotter
than today.

Next week: Main theme will be hotter daytime temperatures with
HeatRisk getting up into the Major category for portions of the
area, especially on Wed and Thu. At this time held off on issuing
any Extreme heat products. Something for later shifts to ponder.
Latest NBM probabilities for 110 degrees for Tucson has 39% on Wed
and 13% on Thu. On the precipitation side, with the upper high
strengthening over the state, this will limit thunderstorm
development. Once again the inherited NBM PoP grids were way to
high for this pattern and well above climatology. Thus in
coordination with our neighbors, went ahead and lowered PoPs Mon
thru Thu but still having chances of afternoon/evening storms
mainly S/SE of Tucson. Depending on how the upper high reorientates
itself late next week, there is the potential for an increase in
daily storm activity from 11th to 13th. Confidence low at this
time with the latest CPC 6-10 day outlook for the area leaning
above normal for precip.

&&

.AVIATION...Valid through 06/12Z.
SCT-BKN 10-14k ft AGL thru 05/19Z...then SCT-BKN 7-12k ft AGL aft
19Z. Isold SCT -SHRA/-TSRA mainly S/SW of KTUS thru 04/04Z with
CIGS BKN 5-8k ft AGL and gusty outflow winds up to 40 kts. Surface
winds generally WLY 8-13 kts, becoming SLY less than 10 kts
overnight. Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Expect isolated to scattered showers and
thunderstorms this afternoon into this evening mainly south and
southwest of Tucson. A decrease in thunderstorm activity is
Sunday into next week as the area transitions into a low grade
monsoon pattern.  An eventual uptick in monsoon activity is
possible the middle of next week but will be dependent on how
quick the high pressure aloft shifts north. Temperatures heating
up this weekend into next week with the potential for very hot
temperatures to return the middle of next week. Winds generally
light and under 15 mph with the exception of gusty and erratic
winds up to 35-45 mph near any thunderstorms.

&&

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

&&

$$

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