Area Forecast Discussion
Issued by NWS Sacramento, CA
FXUS66 KSTO 210409
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SACRAMENTO CA
909 PM PDT Wed May 20 2015
Cool weather with mountain showers and thunderstorms will continue
through the end of the week. A chance of showers and isolated
thunderstorms in the valley for Thursday and Friday. Mostly dry
with warmer weather returns next week except for slight chances of
precipitation over the mountains.
Low pressure area continue over the west coast this evening. We
are still seeing some showers along the coastal range and in the
central valley north of Willows. The showers will continue to
decrease through the evening with a few isolated showers possible
in the overnight hours...mainly over higher terrain.
The low will begin to move south to off the central coast for
Thursday and then move into Southern California for Friday. In
general most of the activity will stay over the mountains but a
few showers or isolated thunderstorms may be able to work its way
into the valley as the low transitions into Southern California.
No major changes in temperatures with below normal highs
continuing through Friday. Decent flow through the delta will
continue as well.
On Saturday a low pressure system will drop down from the north
into Oregon but may be able to bring enough daytime instability
over the mountains to trigger a few showers and thunderstorms.
The low will then move south into Northern California Saturday
night to increase the chances of showers and isolated
thunderstorms. The Sacramento valley may be able to get a few
showers during this time frame.
.Extended Discussion (Sunday through Wednesday)
No major changes made to the extended forecast. Low and associated
trough will be pulling away to the east on Sunday as weak ridging
briefly builds in. Shower and thunderstorm chances will be
limited to along the Sierra crest into the mountains of Shasta
County for Sunday into Monday. Models in somewhat of an agreement
with next system dropping SE from Gulf of Alaska into Pacific
Northwest on Monday into Tuesday. General consensus on track is
that bulk of system would skirt NorCal to the northeast and into
Idaho/Montana, but still some uncertainty at this point. This
would generally continue the pattern of convective chances into
Tues/Weds, mainly across the Sierra and northern mountains. Valley
and most of foothills look to remain dry into mid-week at this
point. Regardless, temperatures should warm a bit by Sunday and
remain rather consistent into mid-week. Highs will range from the
the 80s in the valley to 50s/60s in the mountains. CEO
Mainly VFR conditions next 24 hours in the valley. Areas of
MVFR/locally IFR in showers with isold thunderstorms through this
evening with another round possible after 18z Thurs. Delta breeze
will continue with winds 15-20 kts with gusts to 30 kts before
relaxing to around 15G25 kts tonight. Marine stratus will spread
into the Delta region tonight with brief period of MVFR possible
in the Sacramento region Thursday morning.