Scientific Forecaster Discussion
fxus66 ksto 181045
Area forecast discussion
National Weather Service Sacramento California
345 am PDT Wed Oct 18 2017
dry and mild weather today. Rain chances along with High Mountain
snow and cooler temperatures Thursday and Friday followed by a
warming trend this weekend into early next week.
high cloudiness has shifted further south overnight as west-
southwest flow increases ahead of the approaching late-week
trough. Winds remain generally light and temperatures are running
a bit cooler compared to 24 hours ago across most of the area.
Dry weather with mild temperatures will continue across the region
today. Highs this afternoon are expected to be very similar to
tuesday's with lots of lower to mid 80s throughout the Central
Valley and surrounding foothills.
Unsettled weather still ontrack to return to the region Thursday
and Friday with precipitation, much cooler temperatures and gusty
southerly winds. The wetter mountain areas may see as much as an
inch of liquid precip while the valley will generally see less
than a quarter inch and most locales probably just a few
hundredths. Colder air behind the frontal band is expected to
lower snow levels below the major passes on I-80/US-50 where an
inch or two of snow could accumulate.
Gusty ridge winds can be expected later Thursday as the upper
trof moves inland with a southerly 6-7 mbs rdd-SAC gradient
forecast (not as strong as yesterday) leading to gusts around 30
mph or so. Also, chance of a stratus intrusion into the SAC Vly
Thu morning ahead of the deepening trof, unless the trof mixes it
Warm frontal clouds could return Fri nite with warm air advection precip mainly
staying to our north as strong ridging begins to build for the
Extended discussion (sunday through wednesday)
upper ridging over norcal on Sunday will bring dry and warm
weather to the region into midweek. Valley & Delta highs on Sunday
will be in the upper 70s to low 80s warming into the mid to upper
80s for Monday and Tuesday. Foothill and mountain regions will be
60s to 70s on Sunday with foothills warming into the low 80s for
the start of the work week. A few degrees of cooling possible on
Wednesday when a weak trough could approach norcal.
general VFR conditions with light winds. Local haze/fu MVFR
visibility is possible in the Delta this morning. Valley winds at
taf sites will be less than 10 kts. Winds over higher terrain will
be light with a diurnal pattern.