Scientific Forecaster Discussion
fxus66 khnx 252152
Area forecast discussion
National Weather Service San Joaquin Valley - Hanford California
152 PM PST Sat Feb 25 2017
Synopsis...one weak system will drop southward near the
California coast tonight then another weak system will move
through the area on Monday. These systems will bring some light
precipitation to our area. A warming and drying trend will then
take place between Tuesday and next weekend.
Discussion...another frosty morning took place in the San
Joaquin Valley as most locations had morning lows in the lower 30s
today as mainly clear skies and light winds prevailed overnight.
Meanwhile, satellite imagery is indicating a mid level cloud band
pushing southward through central California today ahead of a low pressure
system centered near 38n/127w which is dropping southward. Short
term models have been indicating this low will continue dropping
southward this afternoon and evening then make an inland turn and
track east across socal overnight through early Sunday. While this
system is fairly weak, it will bring enough moisture to the west
side of the San Joaquin Valley for a light chance of showers this
evening and provide for enough orographic lift over the southern
Sierra Nevada for a slight chance of snow showers. As the low
shifts inland overnight there will be at least a slight chance of
showers across our entire County warning forecast area with the snow level generally
between 3500 and 4000 feet. Snowfall accumulations are expected to
remain light with some mountain locations picking up an inch two
of snowfall accumulations. At this time we do not anticipate much
of an impact from this system over the Kern County passes, but
will monitor this situation closely tonight. One impact this
system will have is that it will provide for increased cloud cover
tonight which will keep temperatures in the San Joaquin Valley
several degrees above the freezing mark on Sunday morning.
This first system is progged to move off to the east on Sunday
while another cold upper trough approaches central California. This
second system is progged to cross central California on Monday and will
provide for chances of showers Sunday night through Monday night.
Quantitative precipitation forecast progs are indicating up to a quarter inch of liquid
precipitation in the southern Sierra Nevada and adjacent foothills
with the snow level lowering to 3000 to 3500 feet by Monday
evening. Only a few hundredths of an inch of precipitation is
anticiapted for the San Joaquin Valley and for the Kern County
mountains and deserts with this system although there might be a
brief period of increased winds with the frontal passage on
A drying trend is expected to begin on Tuesday with as high
pressure strengthens off the California coast. A brisk northerly flow
behind the departed trough will keep temperatures below seasonal
The medium range models and their ensemble means are in fairly
good agreement with building the large high inland during the
remainder of the week which will provide for continued dry weather
and a warming trend with daytime temperatures expected to rise
above seasonal normals by Friday. The ridge is progged to flatten
some next weekend as shortwave energy pushes into the Pacific NW, but
our area will remain under a mild and dry airmass next weekend.
Aviation...local MVFR conditions in clouds and precipitation in
the Kern County mountains between 06z and 12z Sunday. Otherwise, VFR
conditions will prevail across the central California interior during the
next 24 hours.
Air quality issues...none.
The level of certainty for days 1 and 2 is medium.
The level of certainty for days 3 through 7 is medium.
Certainty levels include low...medium...and high. Please visit
www.Weather.Gov/hnx/certainty.Php for additional information
an/or to provide feedback.