Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tucson Arizona
930 am MST Sat may 30 2015
Synopsis...strong high pressure aloft will bring above average
daytime temperatures through middle week. There is a slight chance of
afternoon and evening showers and thunderstorms east of Tucson into
Monday. Otherwise...dry conditions will prevail into the upcoming
Discussion...clear skies prevail across Southeast Arizona at this time
except for a few cumuloform clouds over the White Mountains...and a
few cirriform clouds south-to-southeast of Tucson. 30/12z NAM/GFS
and 30/14z were similar with depicting at least a slight chance of
showers and thunderstorms to be confined to the White Mountains this
afternoon and early this evening. Otherwise...dry conditions will
prevail today along with generally light winds. High temperatures this
afternoon will average about 2-6 degrees or so above normal.
There are no updates planned at this time. Please refer to the
additional sections for further detail.
Aviation...valid through 31/18z.
There is a slight chance of -tsra/-shra mainly across the White
Mountains NE of ksad this afternoon and evening. Otherwise...
scattered clouds generally at 8-12k feet above ground level into this evening mainly
east of ktus to the New Mexico border. Expect clear skies or mostly
clear skies elsewhere and at other times. Surface wind this
afternoon and early this evening will be westerly/northwesterly at 10-15 kts with
occasional gusts to around 20 kts. Otherwise...surface wind will be
less than 10 kts. Aviation discussion not updated for taf amendments.
Fire weather...there is a slight chance of showers or thunderstorms
east of Tucson to the New Mexico border through Monday. The coverage
of showers or thunderstorms Sunday afternoon and evening may be as
far west as the galiuro and Pinaleno Mountains in Graham County...
and perhaps as far west as the Dragoon Mountains in Cochise County.
Otherwise...most of this activity will be across the White Mountains
this afternoon and Monday. Rainfall amounts will be mainly light...
with generally trace amounts to perhaps one quarter of an inch...
although locally heavier amounts may occur. The main concern will be
the potential for brief strong...gusty and erratic winds associated
with any thunderstorms. Dry conditions will then prevail Tuesday
through Friday. Daytime minimum relative humidity values will
generally be in the single digits to middle teens. Expect normal
diurnal wind trends through Sunday...with some gustiness during the
afternoon and early evening hours due to strong daytime heating.
Stronger afternoon winds are then expected early to middle next week.
Previous discussion /205 am MST/...high pressure aloft will continue to
build over the region this weekend bringing the first days of 100
degrees or more to the lower elevations...including Tucson and
Safford. Some middle level moisture increase along with daytime heating
will bring a few showers or thunderstorms to areas east of
Tucson...mainly in the mountains...through early next week. Models
show the ridge breaking down by the middle of next week in response
to a couple of weak systems entering the Pacific northwest. This
will keep a dry flow pattern across the area with daytime
temperatures dropping a few degrees.
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