Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
FXUS66 KHNX 301215
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
515 AM PDT FRI SEP 30 2016
Near normal temperatures today will trend much cooler this weekend
and into the start of next week. Winds will become breezy to locally
windy this evening through early next week. A Pacific storm system
is expected to bring clouds and possibly light showers Sunday evening
through Monday morning.
.DISCUSSION...Satellite imagery shows a cold upper low dropping south
about 350 miles offshore of the Pacific Northwest, with an associated
trough moving over Central California. Synoptic cooling will lower
temperatures several degrees today, down to near climatological norms.
Short wave energy will rotate in over Northern California this evening
driving a cold front through the district and winds increasing behind
the front. Gusty conditions will develop along the west side of the
San Joaquin Valley this evening and into the Kern County mountains
and desert by Saturday morning. Areas of blowing dust will be possible
with gusts of 20 to 30 mph. Further cooling will occur behind the cold
front on Saturday with breezy conditions continuing due an increased
onshore surface pressure gradient.
A colder upper low from western Canada will drop down the back side
of the trough and move over NorCal Sunday afternoon. While the models
continue to show most of the moisture staying well to our north,
a few light showers will be possible Sunday afternoon through Monday
morning. The cold air aloft will steepen lapse rates for increased
instability and upper dynamics could help generate some isolated
thunderstorms from Fresno County north Sunday aftn/eve. With the lack
of significant moisture, rainfall amounts are generally expected to
be very light with just a few hundredths to a tenth of an inch. The
proximity of the low will bring snow levels down to around 6000 feet.
Campers, hikers, and anyone planning travel into the high Sierra from
Yosemite NP to Sequoia NP should be prepared for the potential of
1 to 2 inches of snow. A few light upslope showers will even be
possible down near the Grapevine in Kern County late Sunday night
into Monday morning. The low is progged to quickly shift east over
the Great Basin Monday afternoon with shower activity ending. Winds
will increase again Sunday evening with strong gusts possible in
the Kern County mountains and desert through Monday evening. The
low will bring temperatures down to 15 to 20 degrees below normal
on Monday. A gradual warming trend will occur Tuesday through the
end of next week with dry conditions and lighter winds.
Gusty winds across the San Joaquin Valley this afternoon...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 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.