Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 220347
Area Forecast Discussion
National Weather Service Tucson AZ
847 PM MST SUN AUG 21 2016
.SYNOPSIS...Expect scattered afternoon and evening showers and
thunderstorms again Monday. A drying trend will then limit
thunderstorms to mainly east of Tucson by 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...Showers and thunderstorms had pretty much dissipated
across most of southeast Arizona late this evening. Updated the
forecast to reflect this trend and adjusted temperatures down as a
few spots have been hovering near the projected low temperatures for
tonight. Otherwise, rest of forecast looked on track.
.AVIATION...VALID THRU 23/06Z.
Isolated -SHRA/-TSRA dissipating with partial clearing tonight. More
-TSRA/-SHRA redeveloping Monday afternoon but overall fewer storms
are expected. Otherwise, cloud decks around 10k-15k ft MSL and
surface wind generally less than 12 kts. Aviation discussion not
updated for TAF amendments.
.FIRE WEATHER...Expect scattered thunderstorms through this evening
then somewhat fewer storms Monday afternoon and evening. A drying
trend from west-to-east will occur Tuesday through Thursday, with
only isolated thunderstorms mainly near mountains east of Tucson by
Thursday. Then a bit of an increase in storm coverage is expected
again Friday and Saturday due to an increase in monsoon moisture. 20-
foot winds into next weekend will generally be terrain driven at
less than 15 mph except near thunderstorms.
.PREV DISCUSSION...Isolated to scattered showers/tstms will continue
Monday afternoon/ evening as the mid-level trough axis remains over
southern Nevada/ southern California. A drying trend from west-to-
east across the area is still expected to occur Tue-Thur. 21/12Z
GFS/ECMWF/CMC were similar with moving the upper trough eastward
across the area Tue followed by northerly 700-500 mb flow Wed. These
solutions suggest that Thur may have the least coverage of
Thus, PoPs are configured to depict at least a slight chance of
showers/tstms across eastern sections, with precip-free conditions
west of Tucson. Thereafter, the GFS/ECMWF/CMC remained similar
versus their respective previous solutions in depicting a further
westward influx of moisture starting Friday and continuing into next
weekend. Expect isolated to scattered afternoon/evening
showers/tstms area-wide Fri-Sun.
High temps thru next Sunday will generally average within a few degs
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