Frogville´s Weather Service

Updated:  01-Aug-2026 3:05pm 
  Clear Temperature: 111.4°F   +0.3°F/hr Humidity: 16% Dew Point: 54.8°F Wind: W  3.7 mph Gust: 7.0 mph Barometer: 29.680 inHg  Falling Rain Today: 0.00 in UV Index: 6.3   High 

427
FXUS65 KTWC 012104
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
204 PM MST Sat Aug 1 2026

.SYNOPSIS...Storm coverage and chances increases this afternoon and
evening for areas east of Tucson, but especially ramp up next week
with a more active pattern. High temperatures will be 8-15 degrees
above normal through Monday with gradual modest cooling thereafter.
The Extreme Heat Warning is in effect through Monday.

&&

.DISCUSSION...Plenty of clouds have lingered around through the
morning due to a mesoscale convective vortex (MCV) associated
with a few embedded thundershowers at times over Cochise,
Graham, and Greenlee counties. The lingering MCV has presented a
unique forecast challenge for the afternoon. Clouds and
thundershowers earlier today could inhibit the growth of
instability across favored areas for thunderstorm development
this afternoon and evening (i.e., White Mountains, Chiricahuas,
and perhaps the Pinalenos and even Mount Lemmon). However, there
is still plenty of time left in the day for instability to grow
and overcome the cap as the MCV continues to move west and
south.

Overnight tonight there is uncertainty on whether we see another
round of lingering showers and storms (perhaps in the form of
another MCV south and east of Tucson. The NBM and a few of the
01/12Z REFS members (notably the HRRR and REFS-2) have latched onto
this solution so far across portions of Cochise and Santa Cruz
counties overnight into the early morning hours. The NBM has PoPs
overnight in the 50-70% range for Cochise County, but I bumped them
down into the 20-50%) range and expanded a slight chance (10-20%)
west into Santa Cruz County. This outcome is highly dependent on how
storms evolve in New Mexico this evening but still worth
highlighting.

Tomorrow, another day of similar northeasterly flow aloft will
support storm chances (20-40%) again mainly in the White Mountains
and areas east and south of Tucson. In the early evening I could see
there potentially being a shower or storm in the Tucson Metro based
on a weak but nonzero signal for divergence aloft. However, my
confidence remains rather low at this time.

Monday, the midlevel high is becoming more elongated. There is
increasing confidence for storms to be able to push a bit further
west toward the Tucson Metro. But it still looks like the best
deformation and thus strongest lift and storms are going to set up
in the afternoon over Sonora, Mexico. What is notable about Monday,
however, is the chance for perhaps some nocturnal activity
associated with an MCS south of Tucson along the International
Border. This solution is currently supported by the latest 01/12Z U
of A WRF-GFS. At the very least, thunderstorm outflows in northern
Mexico could send a reinforcing moisture surge into southeast
Arizona as we head into what looks like perhaps an even more active
period in the middle to latter half of the week. The gradual uptick
in moisture each day will cause the threat for localized flash
flooding later in the week.

&&

.AVIATION...Valid through 03/00Z.
FEW-SCT 8k-12k ft AGL ceilings through much of the period. Isolated
to scattered thunderstorms likely 01/21Z-02/03Z with isolated
activity lingering later into the night, mainly near KDUG. Overall
activity mainly near and east of a KE77-KTUS-KOLS line. Gusty
erratic winds of 35-40 kts possible with any thunderstorm with
potentially blowing dust. Otherwise surface winds northwest to west
8-12 kts with occasional afternoon gusts to 20 kts. Surface winds
light and terrain driven after 02/03Z. Scattered thunderstorm
chances return Sunday afternoon and evening. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...
High temperatures will remain well above normal through monday with
with an Extreme Heat Warning in effect. Expect daily chances of
afternoon and evening showers and thunderstorms mainly south and
east of Tucson through the weekend with some day to day variability.
Storm coverage and chances are expected to increase in coverage next
week with an active period in store. Any thunderstorm will bring a
threat of severe, erratic wind gusts with possible blowing dust as
well as brief heavy rainfall and an isolated threat of flash
flooding. Min RH values will be 10- 20 percent through Saturday then
15-30 percent Sunday into next week. Winds will be terrain driven at
5 to 10 mph with occasional gusts up to 25 mph.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Extreme Heat Warning until 8 PM MST Monday for AZZ501>509.

&&

$$

DVS

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NWS TWC Office Area Forecast Discussion