500
FXUS65 KTWC 082047
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
147 PM MST Tue Jul 8 2025

.SYNOPSIS...Low-grade monsoon pattern this week with most of the
daily storm activity being east and south of Tucson. Hotter
daytime temperatures through Thursday with Wednesday likely the
hottest day this week where an Extreme Heat Warning is in effect for
portions of southeast Arizona.

&&

.DISCUSSION...Partly cloudy skies this afternoon across the region
as temperatures warm to levels about 5 degrees above normal for this
time of year. Latest KEMX radar is showing two areas of showers and
thunderstorms developing at this time, the first across the higher
terrain of Graham/Greenlee Counties and another just pushing off the
Chiricahua Mountains. The 18Z KTWC sounding showed a stronger
suubsidence inversion at 500mb today compared to yesterday given
that the high pressure aloft is nearby. Latest GOES PWAT values
range from about 0.9 inches near the NM border to 1.4 inches west of
Tucson. This drier airmass east of Tucson will support gusty outflow
winds with the isolated to scattered storms that do develop south
and east of Tucson for the rest of the afternoon. The most organized
storms today will be to our south in Sonora with the international
border being on the northern edge of this activity. Main concern
today will be the gusty outflow winds with localized areas of
blowing dust near the NM border. While a few storms could produce
brief downpours with the strongest cores, the heavy rainfall threat
is lower today.

For Wednesday, the main headline is the Extreme Heat Warning that is
in effect for most of our forecast area. The forecast high of 111
degrees in Tucson would tie the record from last year. See climate
section below for additional information. With the high pressure
aloft peaking in strength over our area Wednesday, isolated to low
end scattered thunderstorm chances (~20-35%) will continue to the
south and east of Tucson. Strong outflow winds will once again be
the primary concern.

Temperatures will lower a few degrees on Thursday compared to
Wednesday, with some localized areas of major HeatRisk continuing.
However, it isn`t widespread enough to justify continuing the
Extreme Heat Warning for an additional day. In the mid/upper levels,
the high pressure aloft will be enlongating more into an east-west
axis from AZ westward into southern California and eastern Pacific.
This flow pattern will result in a more northwesterly flow aloft
which is not favorable for shower and thunderstorm activity for most
of our forecast area. We continue to depict low grade activity over
Santa Cruz and Cochise Counties where moisture levels are slightly
higher with most of the remainder of southeast Arizona dry. Breezy
west to northwest winds are expected Thursday and Friday in the
upper Gila River Valley.

The high pressure aloft will broaden out a bit this weekend into
early next week while gradually shifting more towards the north.
This will place our region in a more northerly flow this weekend and
then eventually more favorable northeasterly flow early next week.
As this occurs, an uptick in storm chances is expected, initially
for locales east of Tucson Sunday but then expanding west through
much of the forecast area next week. Temperatures will still remain
about 3 to 5 degrees above normal during this period.


&&

.AVIATION...Valid through 10/00Z.
SCT-BKN 7-12k ft AGL with ISOLD-SCT -SHRA/-TSRA mainly S/SE of KTUS
thru 09/04Z with CIGS BKN 5-8k ft AGL and gusty outflow up to 45
kts. Skies will then become SKC-FEW 12-15k ft AGL overnight. Aft
09/18Z, SCT-BKN clouds 7-12k ft AGL mainly S/SE of KTUS with ISOLD-
SCT -SHRA/-TSRA and gusty outfow up to 45 kts again. Otherwise, SFC
winds generally WLY/NWLY 8-13 kts. Aviation discussion not updated
for TAF amendments.

&&

.FIRE WEATHER...Although Southeast Arizona will be experiencing a
low-grade monsoon pattern this week, isolated to low-end scattered
thunderstorm coverage is expected to the south and southeast of
Tucson into the weekend. The main threat for storms will be the
potential for strong gusty and erratic outflow winds 40-45 mph.
Otherwise, an eventual uptick in monsoon activity is possible later
this weekend and into next week as the upper high shifts to a more
favorable location aloft. Temperatures will remain above normal this
week with hottest temperatures Wednesday. Winds generally light and
under 15 mph with the exception of gusty and erratic winds up to 35-
45 mph near any thunderstorms.

&&

.CLIMATE...RECORD OR NEAR RECORD HIGH TEMPERATURES WEDNESDAY

DATE                         Jul 09
                          FCST RCD/YR
TUCSON INTL AIRPORT       111  111/2024
AJO                       113  116/2024
ORGAN PIPE CACTUS         112  116/1958
PICACHO PEAK              109  113/1994
SAFFORD AG STATION        110  108/2024
SIERRA VISTA FD           102  104/2024
TOMBSTONE                 102  106/1979
WILLCOX                   106  109/2003

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 Extreme Heat Warning from 10 AM to 8 PM MST Wednesday for
  AZZ501-502-504>506-509.

&&

$$

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