000
FXUS66 KSTO 042135
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
235 PM PDT Tue Aug 4 2020


.SYNOPSIS...
Gradual cooling returns today and continues through Thursday.
Warmer weather returns for the weekend.

&&

.DISCUSSION...
Water vapor imagery this afternoon shows our weak upper level
disturbance approaching the coast. This will usher in onshore flow
and allow the marine layer deepen. Breezy to gusty winds will
start developing later this afternoon and will continue through
the evening. As the trough moves passes over later tonight and
into tomorrow, it`ll help bolster the marine layer penetration.
Hi-res guidance and NBM suggest that we could see some stratus
making into the southern Sacramento Valley. Afternoon highs for
tomorrow are expected to be around 5-10 degrees cooler than
today`s with the biggest drop where the Delta Breeze has its
strongest influence (Sacramento and Stockton areas). Thunderstorms
remain in the forecast to our north; however, far northwest
Shasta County may see an isolated late day storm.

Trough lingers over the region Thursday and Friday, but heights
aloft will be gradually rising. Onshore flow will be slackening
allowing a gradual return of warmer temperatures.

Wildfire smoke possible at times across the region the next few
days, especially north of Sacramento. Onshore flow expected to
bring considerably higher humidity the next few days.

&&
.EXTENDED DISCUSSION (Saturday THROUGH Tuesday)...


Ensembles continue to depict broad troughing breaking down for the
weekend, which means we will see an increase in high temperatures.
Temperatures will rise back above normal for the weekend and
early next week with Valley highs in the mid 90s to 105 and 70s
to 90s in the mountains and foothills. Although onshore flow will
be weaker than midweek, a moderate Delta Breeze will remain in the
nights which will keep morning lows mild around the southern
Sacramento Valley and portions of the northern San Joaquin
Valley. With the trough breaking down and moving eastward, there
could be some high Sierra thunderstorms this weekend during the
afternoon and the evening hours. Best chances look to be south of
highway 50 and east of the Sierra Crest.


&&

.AVIATION...


VFR conditions next 24 hours. Local southwesterly surface wind
gusts 20-35 kts vicinity Carquinez Strait/West Delta, and local
gusts 10-20 kts elsewhere tonight into Wednesday. Some marine
stratus could spread through the Delta into the Sacramento metro
area, SCT020 12-17z.
&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$