Scientific Forecaster Discussion
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Area forecast discussion
National Weather Service Sacramento California
1050 PM PDT Thu Oct 17 2019
light showers are forecast for the northern mountains and far
northern valley overnight Friday and into the day Saturday.
Otherwise, we expect to see dry and quiet weather throughout the
remainder of the forecast period. Below normal daytime
temperatures this weekend will warm to above normal next week. Mid
week we could see slightly breezy north winds in the valley.
the evening update: frontal system moving into the pac northwest and
trailing back to the nrn California coast will continue to move inland
through Fri with an increase in cloud cover over the County Warning Area. Eka radar
picking up a few weak echoes along the coast at this hour. The NAM
reference prog from the wave shows a few showers over the eka cwa, west of
our area on Fri, so we maintain a dry forecast for interior norcal.
Still looks as if there will be a chance of showers over the nrn
mtns/siernev north of I-80 on Sat as a progressive short wave trof
digs into the Great Basin/central rockys area. Jhm
current satellite imagery indicates some scattered cumulus clouds
sprinkled across much of northern California particularly over
higher elevations. Slightly breezy conditions with gusts in the
15-25 miles per hour range are widespread across northern California with
locally higher gusts over peaks and wind favored areas.
A broad ridge over the eastern Pacific is forecast to build into
our area giving US dry conditions ahead of another weak trough.
This trough is forecast to pass just to our northeast overnight
Friday into Saturday morning and may bring some very light
rainfall to the area. The far northern portion of California will
have better chances for rain especially over higher terrain.
Precipitation chances associated with this weak disturbance end by
Saturday evening as the low shifts east. Slightly breezy
northwest winds could be possible for the San Joaquin Valley on
Saturday evening. Below average temperatures are expected this
weekend before warming to above average by Monday as the eastern
Pacific high nudges eastward.
Extended discussion (monday through thursday)...
Dry weather is forecast for the extended period as ensemble
solutions remain in good agreement that the eastern Pacific high
will nose its way into northern California. High temperatures are
forecast to War a few degrees each day, with most areas being 5
to 10 degrees above their seasonal normals. The next change in the
weather could be mid next week, where we could see locally breezy
northerly to easterly winds as the pressure gradient tightens
VFR conditions are forecast as an area of low pressure exits the
region. Locally gusty northwest winds are favored behind this
trough with gusts of 15-20 kts expected for our southern
terminals 03z Friday. Otherwise, sustained winds generally below