Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 060500
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
900 PM PST Wed Mar 5 2014
A system continues to spread rain into northern California, with
the bulk of precipitation coming Tonight. Breezy to windy
conditions expected through the evening, especially for the
northern Sacramento Valley. Lingering showers during the day
Thursday, with dry and mild conditions for Friday and Saturday. A
wet system is possible late Sunday into Monday.
Showers with isolated thunderstorms continue over the region with
the Sacramento region getting closer to seeing an increase in
activity as band of light rain pushes inland from the west. The
main part of the system will pass through tonight. Snow levels
will remain high for most of the event near 8000 feet but will
lower on Thursday down to around 6000 feet or so but by then most
of the activity will have passed and only some scattered light
snow showers look possible during the day. Winds over the north
end of the valley are expected to come down over the next couple
of hours so we may be able to cancel the wind advisory a little
bit sooner than advertised.
Rainfall amounts have been greatest over the north with one
spotter near Sims in Shasta county reporting over 3 inches of
rain for the day.
Activity over the north will decrease tonight only to increase as
the trough axis with this system passes through the region late
Thursday morning through early afternoon. That`s when we could see
an increase in shower activity for the Sacramento valley and
surrounding mountains relative to the morning activity.
A ridge of high pressure will build behind the system starting
Thursday night to keep the interior dry. Generally Northerly winds
less than 10 mph will develop across the region behind the system
for the valley with northeast to east flow over the mountains.
.Extended Discussion (Sunday through Wednesday)
Not much change to the extended forecast. Models continue to show
good agreement on the arrival of another Pacific front moving into
NorCal Sunday afternoon into Monday. The moisture plume associated
with this storm will be from the tropics and carry PW values
ranging from 0.8-1.3" into our CWA. Even though this moisture is
from the tropics, it does not appear to be remnant moisture from
former tropical cyclone Faxai. Models show that the moisture from
that cyclone will move southward between now and the weekend.
.Previous Extended Discussion...Snow levels with this warm system
will be quite high and generally above 7000 feet so impacts will
be minimal. Due to warm airmass...daytime highs are expected to
come in around normal despite cloud cover and precipitation.
Current model timing of front moves it into the Sierra by early
Monday with rain and snow transitioning to showers during the day
on Monday. Some breaks in the cloud cover Monday should allow some
valley locations to warm a bit. Upper ridging pushes in from the
West by Tuesday morning bringing an end to the shower threat.
Surface high pressure nosing into the Pacific northwest will bring
breezy north winds to the forecast area on Tuesday. Clearer skies
and warmer airmass with bring up daytime highs to a few degrees
Pac fntl sys movg thru Intr NorCal ovngt into Thu mrng with areas
MVFR/IFR and lcl LIFR omtns. Isold TSRA ovngt. Lcl Sly sfc wnd
gsts up to 30 kts N of KSMF thru 09z Thu with S-SW sfc wnd gsts up
to 45 kts poss ovr hyr mtn trrn til Thu aftn. Sn lvls lwrg tngt to
arnd 050-060 amsl by Thu mrng. Mnly VFR Thu exc lcl MVFR/IFR poss
wind advisory until 1 am pst thursday northern sacramento valley.