Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 112246
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
346 PM PDT Tue Mar 11 2014
Building high pressure will result in dry weather and milder
temperatures for the rest of the week. Breezy to strong northerly
winds will continue into tonight. Winds will transition to more
easterly overnight causing breezy winds along the Sierra Foothills
and breezy to gusty across Lake County.
Drier, warmer weather pattern settling into NorCal, but the
primary concern today is wind. Strong north winds are developing
in the Sacramento Valley and this event will be followed by
strengthening easterly winds overnight that will impact the Sierra
Foothills and higher elevations of Lake County. We have
updated the wind advisory to include the strong overnight
easterly winds for Lake County.
Surface high pressure building into Oregon is increasing the
north-south pressure gradient across the region. The MFR to SAC
gradient has increased to 12.1 mbs as of 10 am. Winds at Redding
have just jumped in the past hour with sustained winds around
30-35 mph and gusts over 40 mph. Gusts around Sac Metro region so
far have been ranging 25-35 mph. Gusts across Lake County so far
have ranged 20-45 mph.
The north-south gradient peaks out around midday then gradually
weakens into this evening. However, the east-west gradient
tightens tonight, so the focus of stronger winds will shift
towards the western Sierra slopes with breezy conditions reaching
the foothills but just under advisory criteria. The greater concern for
strong easterly winds will be across Lake County for elevations
above 1000 ft. Strongest gusts will be near ridgetops of Lake
County. Gradients relax Wednesday for lighter winds across the
Mild temperatures expected across NorCal through the remainder of
the week though mountain valleys sheltered from the winds will see
cool morning lows.
.Extended Discussion (Saturday through Tuesday)
Extended forecast continues to show upper level ridging spreading eastward
into the region late this week, with temperatures peaking over the
weekend. Well above normal temperatures are expected, with low 80s
across much of the Valley. Monday is trending dry and just a
little cooler than Sunday. The 12Z ECMWF is showing a closed low
off the coast opening into a wave and moving inland on Tuesday.
This is quite different from the 00z run, which had dry ridging.
The 18z GFS has a similar low off the coast, which weakens and
fills as it tries to move inland Tuesday/Tuesday night. With this
and the big change in the ECMWF, will keep forecast dry for
now. Looking beyond, models are rather chaotic, with an unsettled
EPAC High pres blds into PacNW nxt 24 hrs with VFR conds ovr Intr NorCal.
In Cntrl Vly, areas Nly sfc wnd gsts to 30 kts, dcrsg ovngt.
Omtns, areas N to E sfc wnd gsts up to 45 kts ovngt into Wed, dcrsg
wind advisory until 8 pm pdt this evening carquinez strait and
delta...central sacramento valley...northern sacramento valley...
southern sacramento valley.
wind advisory until 5 am pdt wednesday above 1000 feet in the
clear lake/southern lake county.