Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 271031
Area Forecast Discussion
National Weather Service Sacramento CA
331 AM PDT WED APR 27 2016
Scattered showers and isolated thunderstorms today. Light snow
over the higher elevations of the NorCal mountains. A little
breezy behind this system on Thursday, then dry and warmer.
Water vapor imagery shows incoming trough with tightly wound vort
just off the southwest coast of Oregon. A line of showers
associated with this feature is nearing the NW coast of
California. Higher resolution models continue to indicate that
scattered showers, and perhaps a few thunderstorms, will spread
inland into the northern mountains and northern Sacramento Valley
by late morning.
The models have been pretty consistent tracking the strong vort
southward toward the Bay Area and Sacramento region by 00Z, so
expect to see shower and thunderstorm chances increase in the
Sacramento metro area and northern Sierra Nevada during the
afternoon. Forecast soundings for the Sac area indicate some
pretty healthy CAPE and steep mid-level lapse rates, so moderate
size hail along with brief heavy rain and gusty winds may
accompany stronger storms late today.
An inch or two of snow will be possible later this afternoon into
this evening across the northern Sierra passes which may lead to
some travel impacts for a period of time before showers taper off
later this evening.
The low shifts east into the lower Colorado River Valley by early
Thursday with perhaps a few lingering wrap-around showers
remaining over the Sierra, mainly south of Tahoe. The remainder of
the area will return to dry and milder weather with breezy north
Dry and milder weather is expected on Friday with short-wave
ridging overhead. Another system is forecast to clip the region
Friday night as it drops southward through Nevada perhaps bringing
some showers to the northern Sierra crest.
.Extended Discussion (Sunday thru Wednesday)...
A ridge of high pressure will dominate the long term forecast
period with warm temperatures and quiet weather. The strongest
portion of the high pressure system will be Sunday and Monday,
which as a result, will bring above normal temperatures to the
region. The Valley could see temperatures in the mid to upper 80s,
which would be 10 to 15 degrees above normal for this time of
A higher amplitude trough of low pressure will slide down into the
eastern Pacific just off shore of California Monday and Tuesday.
High temperatures will cool slightly, but ranges will still be
around 5 degrees above normal. Some slight chances for showers are
possible along the Coastal Range, but otherwise no significant
weather or precipitation is expected during the long term period.
VFR conditions are expected at the terminals for the next 24 hour
Winds will be light out of the south and will generally shift to
the west or northwest direction Wednesday night after an upper
level disturbance moves through the NorCal region. There could be
a few wind gusts during the afternoon hours, mainly for the
Stockton terminal. Showers and isolated thunderstorms are
possible with the vicinity of the terminals, but confidence of
direct influence is lessening at this point with short term model
guidance keeping the Valley mostly dry.