Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 102153
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
253 PM PDT Thu Apr 10 2014
High pressure over the western U.S. is bringing generally fair
skies and well above normal temperatures. A series of weak systems
will bring a slight chance of showers and thunderstorms mainly
over the mountains Friday through the middle of next week.
.Short Term Discussion (Today through Sunday)...
Satellite imagery shows high pressure bringing mainly clear skies
across Northern California this afternoon. Upstream, a cutoff low
is currently near 32N 135W and slowly drifting eastward. High
clouds associated with the system have begun to move over Southern
California today, and will be spreading northward tonight and
Temperatures this afternoon are peaking in the lower to mid 80s
across the Valley, with 50s to 70s over the mountains. These
temperatures are 10 to 15 degrees warmer than normal. Expect highs
to be slightly cooler Friday and through the weekend, but remain
well above normal.
The aforementioned cutoff low will move toward Southern California
Friday, and inland Friday night. While most of the dynamics will
remain to our south, weather models have consistently shown that
increasing moisture and instability may bring showers and
thunderstorms Friday and potentially through the weekend. These
showers should be isolated in nature and generally confined to the
higher elevations of the Sierra and Shasta-Trinity/Mendocino
.Extended Discussion (Monday through Thursday)
As high pressure shifts eastward, a low pressure system
approaches the west coast by Monday. Depending on the track of
the low, this will bring some instability for showers and
thunderstorms over the northern portion of the state. The GFS is
much more bullish with this trough while the ECMWF tries to keep
the main energy farther north. By Tuesday, the GFS tracks the low
through northern California which would continue a shower threat
and also notably reduce temperatures and snow levels.
An unsettled west-northwest flow pattern remains over far
northern California through the rest of the extended period,
though model discrepancies keep the strength and timing fairly
uncertain. Have continued shower chances mainly for the mountains
and Shasta County Wednesday and Thursday. Shen
Upr rdg ovhd wkns as ofshr upr low apchs SoCal Fri. VFR conds ovr
Intr NorCal nxt 24 hrs with incrsg high cldns fm the S on Fri.
Genly lgt sfc winds in Cntrl Vly with lcl SWly sfc wind gusts to 25
kts over hyr mtn trrn durg the aftns.