Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
FXUS66 KHNX 292348
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
448 PM PDT THU SEP 29 2016
.UPDATE...Updated air quality issues.
A gradual cooling trend will bring temperatures down to near
normal by Friday then more significant cooling for the weekend
with highs falling to around 10 degrees below normal as additional
cold air invades the region.
The upper level trough dropping south from the northeast Pacific
is beginning to influence our weather across Central California.
Flow has become more southwesterly and just a few small showers
have developed over the mountains. These are expected to diminish
this evening with the loss of daytime heating. Temperatures
across the area are running a few degrees lower than this time
Models are in good agreement with the track of the approaching
trough. Temperatures will continue the cooling trend to near climo
Friday with the approaching trough, then a cold front will track
through our area Friday evening bringing more significant cooling
for the weekend. By Monday as additional colder air moves in, we
will see high temperatures around 20 degrees below normal.
Temperatures will then trend back to around seasonal averages by
the middle of next week as the trough lifts out.
Winds will become Gusty as the front moves through Friday evening
and will kick up areas of blowing dust. Expect stronger winds
through the mountains and desert areas of Kern County Sunday and
Monday on the back side of the passing trough.
Though the initial frontal passage looks dry Friday, more model
solutions are showing precipitation extending farther south into
our area as the main trough moves in. Our forecast now includes
precipitation chances in far northern portions of our Valley zones
and down into Tulare County over the higher elevations. Best
instability will be north of our area but the cold core aloft will
brush the area Sunday and we can not rule out a few thunderstorms
Sunday afternoon and evening. Guidance also suggests the chance
for some upslope clouds and light precip Monday on the backside of
the trough. Snow levels will lower to around 6000 feet with the
storm but qpf shows no more than an inch or two expected at the
highest elevations. This will however be enough to briefly impact
higher roads such as Tioga Pass and the change to more winter
like conditions can be hazardous for hikers and campers in the
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.