Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
FXUS66 KHNX 081153
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
353 AM PST Thu Dec 8 2016
A low pressure system will bring periods of precipitation to the
area today through Saturday with the best chances from Fresno
county northward. Unsettled conditions continue Sunday and early
next week but precipitation chances are not as likely in our area
as the pattern shifts farther north.
An upper low in the Gulf of Alaska will spin off a series of
shortwaves over the next few days, drawing a good fetch of
moisture across the Pacific and into California. The first impulse
brought some rain and Sierra snow overnight. Rainfall amounts were
light in the San Joaquin Valley, with many places north of Kern
County receiving a few hundredths of a inch. Heaviest rain was
near Yosemite where around a quarter of an inch to a just over a
half an inch of rain has fallen overnight. Snow levels have risen
to near 7000 feet and are expected to rise above 8500 feet by
Models are in general agreement with the evolving pattern through
the weekend. The CWA remains in a zonal type flow with periodic
surges of energy and moisture bringing precipitation chances to
the area through the end of the week. Timing and trajectory of
these impulses is still somewhat uncertain and poses a challenge.
The 00Z model runs suggest that Friday may see the precipitation
shift a bit farther north before another wave drops southward
again on Saturday. Thus the best chance of rain will be from
Fresno County northward during much of the period through
Saturday, especially in the higher terrain. Chances decrease
farther south but slight chances extend into Kern county through
the period. Snow levels will remain high.
From today through Saturday, total qpf is expected to range from
1/3 to 1/2 inch in the far northern portions of the San Joaquin
Valley to just a few hundredths in the south. In the Sierra
Foothills, rainfall will range from around an inch near Mariposa
to only about 2 tenths of an inch in Tulare county. In the higher
terrain, up to 2 inches of rain could fall near Yosemite to less
than we should see around an inch in the foothills up to a few
inches in the higher Sierra, with amounts tapering off to less
than a third of an inch near Sequoia Park. Snow levels are
expected to climb to remain above 8000 ft from this afternoon
through Saturday. By the time we get to Saturday afternoon, snow
accumulations could amount to one to two feet near Yosemite with
much less to the south.
Early next week, there is general agreement in the models that
the Pacific ridge will amplify a bit and steer the moisture track
farther north of our area. This will limit precipitation chances
to the far northern part of our CWA Monday through Wednesday. On
Thursday, there are indications that another low pressure system
will move out of the Gulf of Alaska and bring a trough across
California, once again increasing the chance of precipitation
across the region.
Across the San Joaquin Valley, areas of MVFR and local IFR possible
in showers. In the Sierra Nevada, MVFR/IFR with precipitation and
mountain obscurations. VFR conditions will prevail across the desert
in Kern County.
.AIR QUALITY ISSUES...
On Thursday December 8 2016... Fireplace/Wood Stove Burning
Status is: No Burning Unless Registered in Kern... Kings and
Tulare Counties. Further information is available at Valleyair.org
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.