Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 290951
Area Forecast Discussion
National Weather Service Sacramento CA
251 AM PDT FRI APR 29 2016
A chance of showers over the Sierra this evening through Saturday.
Thunderstorms possible over the Sierra Sunday afternoon and
evening. Breezy north winds developing this evening through
Saturday. Showers possible most areas by next Thursday. Above
normal daytime temperatures.
High pressure over the west coast bringing fair skies most areas
this morning. Early morning temperatures are running a bit warmer
than 24 hours ago. A weak frontal band now moving into the Pacific
Northwest is bringing some cloud cover to the far north state this
morning. This system is forecast to clip the north state today
dropping into the Great Basin by Saturday morning. A few showers
may be possible over the Sierra this evening but with high snow
levels and minimal QPF, impacts over the Sierra will be minimal.
The weak system will likely not even have much impact on daytime
highs today with max temperatures remaining above normal. Surface
high pressure pushing in behind todays system combined with
northerly flow aloft will produce breezy north winds tonight and
Saturday. The strongest winds are expected along the west side of
the Sacramento valley and coastal range. A wind advisory will be
issued for late tonight and Saturday for this area. These winds
should drop off by Saturday night and early Sunday as high
pressure aloft pushes in over the west coast. The low over the
southern Great Basin is expected to remain in place however with
the GFS, ECMWF and GEM models all pivoting an upper shortwave
westward around the top of the low and into eastern California on
Sunday afternoon. Models show enough instability for a threat of
thunderstorms over the northern Sierra into the evening hours.
Elsewhere will remain dry with warming temperatures on Sunday.
Wrap around moisture from the Great Basin low will continue to
bring a threat of showers over the Sierra Cascade range on Monday
while the remainder of the forecast area remains dry with slightly
lower daytime highs.
.EXTENDED DISCUSSION (Tuesday THROUGH Friday)
Upper low in EPAC slowly approaches NorCal Tuesday into Wednesday
bringing synoptic cooling and a threat of showers over the
mountains. Models differ with track of low but pattern suggests
increased potential for showers over Interior NorCal Thursday
into Friday with possible afternoon thunderstorms over the
NWly flow alf as upr low movs acrs NE CA this aftn into Sat. VFR
conds for Intr NorCal nxt 24 hrs exc lcl MVFR/IFR conds poss in
shwrs acrs NE and E mtns tngt into Sat. Areas of Nly sfc wnd gsts
to 30 kts or gtr tngt into Sat.
Wind Advisory from 11 PM this evening to 5 PM PDT Saturday for
Carquinez Strait and Delta-Central Sacramento Valley-Clear
Lake/Southern Lake County-Mountains Southwestern Shasta County
to Northern Lake County-Northern Sacramento Valley-Northern San
Joaquin Valley-Southern Sacramento Valley.