Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 230951
Area Forecast Discussion
National Weather Service Tucson AZ
250 AM MST TUE AUG 22 2016
.SYNOPSIS...A drying trend will continue to limit thunderstorms to
mainly east of Tucson through Thursday. Isolated to scattered
afternoon and evening thunderstorms should return by next weekend.
High temperatures will generally be within a few degrees of normal
into next weekend.
.DISCUSSION...Last nights upper air plots showed an upper level trof
extending from e-central UT SW across srn NV into srn CA. Scattered
thunderstorms were occurring across NW AZ down to near the Phoenix
area. Across SE AZ, it was clear to partly cloudy under SW flow
aloft. The above mentioned upper level trof will continue to push
across northern AZ today with bulk of thunderstorm activity
occurring across the northern half of AZ. With PW values below 1"
across the area, it will be a down day thunderstorm wise with a few
developing over the higher terrain east of Tucson. Highs today
will be similar to what occurred on Monday. The flow aloft tonight
becomes NW with the passage of the upper level trof.
A trailing upper level trof will move across the area on Wednesday.
Enough moisture will be around, especially E-NE of Tucson, for a
chance of afternoon and early evening storms.
Thunderstorms on Thursday relegated to the higher terrain near the
AZ/NM border and along the international border. Sonora should be
more active Thursday night as an inverted trof will be passing by
south of this area.
Some of this moisture will be advected north on Friday for the
potential for an areal increase in scattered afternoon/evening
showers and thunderstorms.
Scattered showers and thunderstorms to start the upcoming weekend
then drier air pushes in from the west on Sunday limiting storms to
areas east of Tucson.
Highs for the most part this week into the weekend will be near late
August normals. Triple digit highs return to the low deserts early
next week as high pressure aloft expands over the desert southwest.
.AVIATION...VALID THRU 24/12Z.
Scattered cloud decks at 10-14k ft agl. Isold -TSRA/-SHRA developing
after 23/19z mainly over mountains east of KTUS. Clearing skies
expected aft 24/04z. Surface wind generally less than 12 kts through
the forecast period, except in the upper Gila River valley in the
vicinity of KSAD where surface wind will be nwly at 12-17 kts
between 23/20z and 24/02z. Aviation discussion not updated for TAF
.FIRE WEATHER...Isolated thunderstorms will occur mainly near
mountains east of Tucson through Thursday. Isolated to scattered
coverage is then expected Friday through Sunday from Tucson eastward
as monsoonal moisture increases from the southeast. 20-foot winds
into the upcoming weekend will be terrain driven and less than 15
mph in most locations. Expect the potential for strong and gusty
winds near thunderstorms...and a little stronger afternoon and early
evening winds in the upper Gila River valley, with northwest winds
around 20 mph through Thursday.
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