Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 291610
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
910 AM PDT Tue Jul 29 2014
Moisture surge will bring a few sprinkles and thunderstorms to
portions of interior NorCal into mid-week. Hot afternoon
temperatures this week with a delta breeze each day bringing
decent cooling at night for the valley.
Water vapor imagery shows the monsoonal moisture push that
brought some isolated sprinkles to valley early this morning is
in the process of rotating clockwise into Nevada. Additional
moisture will rotate in from the south over the next couple of
days but the moisture will struggle to find sufficient lift to
initiate convection outside of orographic lift generated from the
Sierra Nevadas. Steering flow aloft will guide convective cells
primarily east of the Sierra Nevada crest.
The overall pattern will remain fairly consistent through the end
of the week as high pressure remains over the Four Corners.
Temperatures will remain hot throughout the region with only
slight differences day to day due to the strength of onshore flow
and the extent of cloud cover.
.Extended Discussion (Saturday through Tuesday)
Models show the western CONUS ridge maintaining it`s position
over the Intermountain Rockies through the extended, Friday to
Monday, with fairly weak S to SSW flow aloft. The resultant flow
aloft will bring some monsoonal moisture northward into the
Sierra. Therefore, we have left a minimal thunderstorm threat over
the Sierra crest south of Highway 50 and around the periphery of
Shasta county. Temperatures remain around normal, with the mid to
upper 90s in the valley and 70s to 90s in the mountains/foothills.
Of course, temperatures will depend on the resultant cloud cover.
The ECMWF and GEM models show an embedded weak low feature aloft
moving toward the central CA coast Saturday/Sunday, and could add
some instability over northern CA. However, we didn`t bit on any
additional convective coverage this feature this far out as it is
very subtle at this point. JClapp
Mainly VFR next 24 hours. 15-25 kts through delta. Isolated showers
possible through 18Z, then afternoon TS over mountains today.