Area Forecast Discussion
Issued by NWS Tucson, AZ

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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

000
FXUS65 KTWC 091637
AFDTWC

Area Forecast Discussion
National Weather Service Tucson AZ
935 AM MST Sat Dec 9 2017

.SYNOPSIS...Warmer temperatures this weekend. A weak disturbance
will move across northern Mexico Monday into Tuesday, bringing in a
slight chance of showers across the southern half of Cochise county.
High pressure aloft will then persist through the rest of next week,
with dry conditions and above average daytime temperatures.

&&

.DISCUSSION...Thin cirrus pushing in from the southwest with thicker
areas of cirrus seen on satellite imagery over northern Baja to off
the Baja coast. These clouds will continue to overspread the area
for the rest of the day into Sunday. The morning Tucson sounding
showed significant warming has occurred above the surface in the
past 24 hours. This will translate to warmer high temperatures today
with highs up 25-10 degrees versus Friday.

&&

.AVIATION...Valid thru 10/12Z.
High clouds will be spreading in from the SW during the fcst pd.
SFC wind ELY/SELY at 10-15 kts with higher gusts thru the fcst pd.
Aviation discussion not updated for TAF amendments.

&&

.FIRE WEATHER...Dry conditions are expected across most of the
forecast area the next seven days, with just a slight chance of
showers across the southern half of Cochise county Monday afternoon
into early Tuesday. Expect east to southeast 20-foot winds at 10-20
mph today and Sunday, with some gusts to 20-30 mph. There will be
some elevated fire weather concerns with near Red Flag conditions
expected in a few locales on Sunday, although these conditions are
not expected to be widespread. Winds will then decrease on Monday
and beyond while still maintaining an easterly component.

&&

.PREV DISCUSSION...Overall, high pressure aloft will strengthen
across the western United States this weekend persisting through
next week. The highly amplified ridge pattern will stretch from the
desert southwest into the Pacific northwest, keeping the main storm
track well north and east of our area. Expect dry conditions for
most of southeast Arizona (more on this below) and daytime
temperatures 3-7 degrees above normal through this period. There
will be increasing high clouds later today into Monday (when there
will be a mix of mid/high clouds), as well as some elevated
east/southeast winds today and Sunday with wind speeds generally in
the 10 to 20 mph range.

The models still indicate a weak upper low developing west of the
Baja spur on Sunday, moving east across northern Mexico Monday and
Tuesday. Flow around this low pulls moisture northward through
Sinaloa and Sonora as it moves eastward. The latest runs are more
robust with this moisture and therefore have introduced slight
chance pops across the southern half of Cochise county late Monday
through early Tuesday. However, with the strength of the high
pressure ridge and very dry air in place (the KTWC 171209/00Z
sounding had a PW of 0.26") any moisture transport into the area
will have a difficult time producing much more than virga and/or
sprinkles, at least initially.

&&

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

&&

$$

Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.