Area Forecast Discussion
Issued by NWS Tucson, AZ
FXUS65 KTWC 210406
Area Forecast Discussion
National Weather Service Tucson AZ
905 PM MST SAT AUG 20 2016
.SYNOPSIS...Expect scattered afternoon and evening showers and
thunderstorms through Monday. A drying trend will then limit
thunderstorms to mainly near the New Mexico border by next Thursday.
High temperatures will generally be within a few degrees of normal
during the upcoming week.
.DISCUSSION...Still looking at some isolated to scattered showers
and thunderstorms across southeast Arizona late this evening. The
bulk of the activity was north and west of Tucson most of the
afternoon and evening. However, recent radar trends indicated a few
thunderstorms moving into northwest sections of the greater Tucson
area around Marana. Latest HRRR solution suggested that this
activity will be short-lived though. Current forecast after midnight
tonight still looked in good shape, so no additional updates are
expected this evening. Please refer to the previous forecast
discussion sections for more details.
.AVIATION...VALID THRU 22/00Z.
The bulk of the -TSRA/-SHRA this evening will end by 21/07Z, then
scattered -TSRA/-SHRA mostly east to south of KTUS Sunday afternoon.
Otherwise, cloud decks around 10k-15k ft msl and surface wind
generally less than 12 kts through Sunday afternoon. Aviation
discussion not updated for TAF amendments.
.FIRE WEATHER...Expect isolated to scattered mainly afternoon and
evening showers and thunderstorms through Monday. A drying trend
from west-to-east will then occur Tuesday through Thursday, with
only isolated thunderstorms mainly near mountains east of Tucson by
Thursday. Isolated to scattered thunderstorms will then prevail next
Friday and Saturday. Winds through the period will favor typical
upslope/downvalley diurnal trends except near thunderstorms.
.PREV DISCUSSION...Enough moisture will then prevail for more
scattered afternoon/evening showers/tstms Sun-Mon. Thereafter, the
20/12Z GFS/ECMWF/CMC were quite similar with depicting a pronounced
drying trend from west-to-east across the area Tue-Thur. This drying
trend is due to somewhat stronger westerly flow aloft which is in
response to a longwave trough moving eastward across the
Based on these solutions as well as per coord with neighboring
WFO`s, PoPs were lowered thru the Tue-Thur period. The expectation
by next Thur is for afternoon/evening showers/tstms to be confined
to near mountains east of Tucson, although would not be surprised
for this activity to be only limited to near the New Mexico border.
Some increase in progged moisture then justifies isolated to
scattered afternoon/evening showers/tstms area-wide Fri-Sat.
High temps during this forecast period will generally be within a
few degs of normal.
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