Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 260944
Area Forecast Discussion
National Weather Service Tucson AZ
240 AM MST MON SEP 26 2016
.SYNOPSIS...A persistent low pressure system will bring gusty winds
today, along with a chance of showers and thunderstorms through
midweek. A gradual drying trend will then occur during the latter
part of the week, with dry conditions returning area-wide next
Sunday. Expect cooler temperatures today, then daytime temperatures
returning closer to normal late in the week.
.DISCUSSION...Water vapor imagery this morning showed a closed upper
level low over central Baja. This feature will be the weather driver
for the area through Thursday. Cloud cover this morning will
continue to spread east to west across the area with isolated
showers become scattered later this morning into this afternoon. A
few thunderstorms are also possible. Tight pressure gradient will
bring strong gusty east winds to the area. We went ahead and
expanded the wind advisory a little further north and included the
A break in the showers this evening then redeveloping overnight as
the upper low starts to lift north. This low will start to tap into
some tropical moisture from tropical depression 18E. For Tuesday
afternoon there is the potential for isolated severe storms mostly
west of Tucson. Can`t rule out areas of blowing dust.
The upper low is progged to be over southern California on Wednesday
with a chance of showers/storms across eastern half of forecast area.
A chance of showers/storms Thursday across eastern sections as upper
low opens up in advance of upper level trof approaching Pacific NW.
Drier air moving across the area on Friday will limit chance of
storms near the AZ/NW border.
Well below normal high temperatures with gradual warming trend by
late in the week.
.AVIATION...Valid through 27/12Z.
-SHRA/-TSRA to increase from southeast to northwest across the area
this morning into this afternoon. MVFR conditions with occasional
higher terrain obscurations especially today. Otherwise, cloud decks
will mainly be 10k-15k ft MSL thru the period. Surface wind ely/sely
at 12-25 kts with gusts to near 40 kts. Aviation discussion not
updated for TAF amendments.
.FIRE WEATHER...Scattered showers with isolated thunderstorms
area-wide today. Stronger thunderstorms may occur Tuesday,
especially from Tucson westward into western Pima County. A chance
of showers and thunderstorms exists Wednesday into Thursday mainly
east of Tucson, then showers and thunderstorms Friday into next
weekend should be limited to near the New Mexico border.
Expect strong and gusty east winds into this evening. 20-foot winds
will likely be mainly in the range of 15-25 mph with higher gusts.
Winds should decrease Tuesday followed by elevated southwest
afternoon winds during the latter part of the week.
Wind Advisory until 8 PM MST this evening for
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