783
FXUS66 KSTO 151311 CCA
AFDSTO

Area Forecast Discussion
National Weather Service Sacramento CA
315 AM PDT Wed Aug 15 2018


.SYNOPSIS...
Dry with near normal temperatures through Thursday, then above
normal Friday through early next week. Smoke impacts from
wildfires continue.

&&

.DISCUSSION...
Interior NorCal sandwiched between upper troughing off the West Coast
and high pressure over the Desert SW. Monsoonal moisture continues
to lift north through the CWA, and 88D showing some light returns
over Eastern Shasta county attm. Higher resolution models indicating
moisture and threat of showers will lift north of the CWA early this
morning. Flow through the Carquinez Strait has been strong overnight
with marine layer about 2k ft deep. Expect some stratus will advect
through the Delta area this morning. Short wave trough approaches
the West Coast today with continued enhanced onshore flow. High
temperatures forecast to be near to slightly below normal.

Secondary upper trough approaches the NorCal coast Thursday and
moves through into early Friday. Onshore flow forecast to weaken
some Thursday allowing for minor warming in Delta breeze
influenced areas. Little change in high temperatures expected
elsewhere across the CWA Thursday.

Heights rise Friday as shortwave upper ridging approaches, then
moves through Saturday. Warming expected over the forecast area
Fri/Sat with highs increasing to above normal. Widespread triple
digit max temperatures return to the Northern Sacramento Valley
Saturday with upper 90s elsewhere in the Central Valley.

PCH

&&

.EXTENDED DISCUSSION (Sunday THROUGH Wednesday)
Norcal will start out extended period under upper level southwest
flow between high pressure over the southwest U.S. and a weak
trough over the northeast Pacific. This stable pattern should keep
any showers or thunderstorms out of the forecast. Despite onshore
flow aloft. airmass will remain warm enough for daytime highs to
remain a few degrees above normal. A slight cooling takes place
early to mid next week as the weak system off the Pac NW coast
unsuccessfully tries to push inland. Even with the slight cooling
Monday and Tuesday, daytime highs remain a few degrees above
norms. Little change on Wednesday as Southwest U.S. ridge holds
strong. Kept haze in forecast across CWA through the extended
period as fires over norcal showing no signs of going away in the
near future.

&&

.AVIATION...
Local MVFR/IFR conditions in HZ/FU near wildfires, otherwise VFR
continues over the area for the next 24 hours. Winds below 15
knots except Local SW surface wind gusts 25 to 30 kts vicinity of
the Delta. A slight chance of thunderstorms over the northern
Sierra crest south of U.S. 50.

&&

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

$$