Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 111730
Area Forecast Discussion
National Weather Service Sacramento CA
930 AM PST THU FEB 11 2016
Dry and mild weather through Tuesday with above normal
temperatures. Pacific storm expected to bring widespread
precipitation around the middle of next week.
High amplitude ridge axis over the Great Basin with southwesterly
flow aloft over Interior NorCal as weak Pacific frontal system
approaches. Considerable amount of CI/CS moved over the forecast
area overnight to hinder development of fog in the Central Valley.
Variable mid to high level cloudiness will continue to stream into
the area over the next 24 hours, bringing slight cooling and
limiting nighttime valley fog formation.
Frontal system nearing 130W is forecast to weaken as baroclinic
zone becomes elongated and battles with strong downstream ridge.
Main focus for precip is aimed into the PacNW. Southern portion
of front will bring a threat of some light precip to the far NW
California coast and coastal interior but not expected to reach
into our forecast area. Weakening surface boundary and associated
upper trough move across far northern portions of CA Friday night
into Saturday morning with little impact other than some clouds.
Heights and thicknesses forecast to increase over the weekend as
upper ridge amplifies along 130 W. High temperatures expected in
the upper 60s to lower 70s for the Central Valley and there could
be some patchy valley morning fog but not expected to be dense,
widespread, or long lived. Weak system rides over the ridge Sunday
with some light overrunning precip possible into far northern
portions of CA, but looks to remain north of our forecast area.
Surface high pressure builds through Oregon into the Great Basin
Sunday with some breezy northerly winds possible Sunday afternoon
.EXTENDED DISCUSSION (Monday THROUGH Thursday)
The ridge axis shifts over NorCal early next week with a 585-586dm
High center to the SW toward 35N 127W. The NAEFS low level
anomalies are 4+ Mon and Tue just off the SoCal coast, while
NorCal anomalies are less than 2. Interior NorCal shows a heat
return period every 2-5 years Mon and Tue, with hottest day on Mon.
Once again, portions of the forecast area (especially the southern
area) will flirt with near record maxes. Breezy north to northeasterly
winds expected Monday and overnight.
Models are still forecasting a fairly dynamic frontal system to
impact NorCal Wed and/or Thu with snow levels below 5000 ft by
Thu. The trough pattern recognition warranted mention of
thunderstorm activity in the Valley and foothills Wed through Thu,
but the coverage and timeframe may change as the our vision
VFR conditions today with light winds. Some patchy MVFR-locally
IFR fog formation possible again Friday morning across San
Joaquin and southern Sacramento Valley.