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fxus66 ksto 241004 
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Area forecast discussion
National Weather Service Sacramento California
304 am PDT Wed may 24 2017



Synopsis...
cooling today into Friday with near to slightly below normal
readings by the end of the week. A slow warming trend over the
weekend and into next week. Isolated afternoon showers or
thunderstorms possible over the northern interior mountains
Wednesday and over the northern Sierra Saturday through the middle
of next week.
&&

Discussion...
break down of upper ridge over the West Coast will bring
significant cooling today on the order of several degrees most
areas and as much as 10-15 degrees in Delta influenced areas.
These areas influenced by the increased Delta breeze this morning
are currently running a few to several degrees below 24 hours
ago. Fort Ord profiler showing the marine layer around 1000 feet
or similar to 24 hours ago so not expecting a major marine layer
intrusion but may see some minor stratus in the Delta. An upper
trough dropping through the Pacific northwest may produce enough
instability for some clouds and isolated thunderstorms over the
northern mountains this afternoon and evening but the rest of the
County Warning Area will remain under mainly fair skies. Weak troughing will
develop across the West Coast on Thursday bringing still more
cooling and a continued sturdy Delta breeze. Temperatures level
off on Friday most areas and are forecast to come in around normal
or slightly below for Delta influenced areas.

Upper ridging rebuilds over the West Coast going into the weekend
allowing for a warming trend and a weakening Delta breeze. Daytime
highs Saturday will pop back up above normal beginning a warming
trend extending into next week. GFS shows some moderate mid level
instability over the northern Sierra Saturday afternoon so have
kept slight thunderstorm threat there for the afternoon and
evening hours.

&&
Extended discussion (sunday through wednesday)

Strong ridging will remain in place for Sunday into Memorial Day,
continuing dry weather and above normal temperatures. Those with
outdoor Holiday plans should be prepared for the heat. Highs will
top out near the century mark across the northern SAC valley on
Monday with 90s elsewhere in the valley, and 60s- 70s in the
mountains. Delta Region will be noticeably cooler thanks to
onshore flow and presence of Delta breeze. Ridge flattens out and
begins to shift off to the east Tuesday as trough slowly
approaches the West Coast for the middle to end of next week.
This will allow for a cooling trend with more seasonable
temperatures and continued onshore flow. May be enough
instability around for isolated thunderstorms across the Sierra
and northern mountains each afternoon/evening, but confidence
remains low in how widespread activity may be given limited
moisture. Therefore, haven't made major changes to current precip
forecast.

Ceo

&&

Aviation...

VFR conditions next 24 hours at taf sites. Gusts to 30 kts invof
of the Delta and 20 kts across northern SAC valley today.



&&

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