Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
FXUS66 KHNX 302054
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
154 PM PDT FRI SEP 30 2016
Cooling trend this weekend and into the start of next week as a
frontal system moves through the area. Winds will become breezy to
locally windy tonight through early next week possibly picking up
loose dirt and dust. Showers and high elevation snow expected Sunday
through Monday morning over the northern half of the forecast area.
.DISCUSSION...Just a few cumulus clouds over the Kern County
Mountains and Sierra this afternoon otherwise skies are sunny.
Water vapor imagery shows the incoming cold Pacific system now
slowly pushing into Northern California. Forecast models slowly
push the associated dry surface front into the area this evening
and the high resolution rapid refresh model brings a rapid
increase in winds by late afternoon and especially this evening.
Although wind advisory level speeds are not expected, blowing dust
will certainly be an issue locally.
For Saturday, with the pattern over the U.S. having a classic
omega block, the low pressure centered near 35N/130W will have a
difficult time moving much to the southeast. Given this, forecast
models really just pivot the low center slightly east through
much of Saturday then by Saturday night and early Sunday, move the
center to a position just off the Northwest California coast. The
low is then progged to push east across Northern California on
Sunday afternoon and evening. This will bring the best chance of
precipitation the the Sierra during this time frame along with
colder air. At this time, forecast precipitation amounts look to
be light with maybe 1-2 inches of snow over the Yosemite high
country by Monday morning. Many areas from Fresno County north
will see light measurable rain but again, light is the key word.
The low is then forecast to move east in the Rockies by Monday
night leaving the Central California Interior in a much cooler but
dry and stable airmass in a northwest flow. Monday looks to be the
coolest day with highs only reaching the 65-70 degree in the San
Joaquin Valley and 60-70 in the Kern County desert. Mountains will
be much cooler thus the feeling autumn will be here.
Looks like a warming trend will occur next week as a low amplitude
ridge moves over the region. Unlike the past several ridge
episodes, this one will not bring any 90s, rather just the 80s for
the high readings in the lower elevations.
A dry cold frontal passage will bring gusty west to northwest winds
up to 25kt across the San Joaquin Valley this evening. Otherwise VFR
conditions will prevail over the central California interior during
the next 24 hours.
.AIR QUALITY ISSUES...
The level of certainty for days 1 and 2 is high.
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.