Area Forecast Discussion
Issued by NWS Tucson, AZ

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
FXUS65 KTWC 230428

Area Forecast Discussion
National Weather Service Tucson AZ
927 PM MST Thu Jun 22 2017

.SYNOPSIS...Very hot temperatures will continue into this weekend.
Dry conditions will also prevail for much of the area into Saturday.
A more favorable pattern will then provide scattered afternoon and
evening thunderstorms Sunday into the middle of next week.


.DISCUSSION...A few showers and thunderstorms this afternoon and
earlier this evening near the International Border and Nogales had
dissipated. Expecting similar activity again tomorrow before more
scattered showers and thunderstorms develop this weekend into the
middle of next week. Otherwise, still looking at extreme daytime
temperatures the next few days. Current forecast looked in good
shape, so no additional updates anticipated late this evening.
Please refer to the other sections in this product for more details.


.AVIATION...Valid thru 24/06Z.
Expect clear skies to scattered clouds at 10k-15k ft AGL into Friday
evening. Surface wind nwly 10-25 kts with gusts to 35 kts again
Friday afternoon. The strongest wind speeds will be east of KTUS and
particularly near KSAD. Surface wind variable in direction less than
12 kts at other times. Aviation discussion not updated for TAF


.FIRE WEATHER...Dry conditions will prevail across much of the
area through Saturday. The exception is across the higher terrain
along the New Mexico border and the White Mountains where there is a
slight chance of thunderstorms. A more favorable pattern for
thunderstorms will then prevail Sunday through next Thursday. Expect
scattered afternoon and evening thunderstorms, especially east to
south of Tucson. However, the coverage of thunderstorms Monday into
Tuesday may expand further west to also include Fire Zone 150 west
of Tucson.

Otherwise, 20-foot winds will generally be terrain driven and less
than 15 mph. The exceptions are early this evening and Friday when
some gusty northwest winds will occur east of Tucson, especially in
the Upper Gila River Valley. The combination of the gusty winds and
minimum relative humidity values of 5 to 10 percent may create
critical fire weather conditions in the upper Gila River Valley, but
these conditions are not expected be widespread nor long-lived.


.PREV DISCUSSION...The 22/12Z GFS/ECMWF/CMC were in general
agreement with depicting an increase in the coverage of
showers/tstms starting Saturday afternoon. A chance of showers/tstms
exists Saturday afternoon/ evening across the White Mountains, and a
slight chance of showers/tstms also exists mainly near mountains
east-to-south of Tucson.

A more extensive westward influx of deeper moisture is then progged
to occur Sunday into Monday as the upper high remains quasi-
stationary over the area. The ECMWF continued to be more robust
versus the GFS and CMC regarding the westward extent of the deeper
moisture. At any rate, chance-category PoPs exist for most locales
east-to-south of Tucson Sunday afternoon/evening, and a slight
chance of showers/tstms is also depicted as far west as the Tohono
O`odham Nation. Western Pima County is then included in a slight
chance of showers/tstms Monday afternoon/evening with similar PoPs
elsewhere as depicted Sunday.

Thereafter, these solutions were similar with depicting a very
gradual daily reduction in shower/tstm coverage Tuesday into next
Thursday. Although a gradual reduction in coverage should occur,
believe there will be enough moisture to justify a slight chance of
showers/tstms next Thursday generally from Tucson south-to-southeast
across Santa Cruz/Cochise Counties.

The Excessive Heat Warning continues until 7 pm MST Sunday for all
elevations below 5000 feet and the Baboquivari Mountains including
Kitt Peak. The Heat Advisory also continues until 7 pm MST Sunday
for all other mountain zones.


 Heat Advisory until 7 PM MST Sunday for AZZ510>514.

 Excessive Heat Warning until 7 PM MST Sunday for AZZ501>509-515.




Visit us on Facebook...Twitter...YouTube...and at is the U.S. government's official web portal to all federal, state and local government web resources and services.