Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
FXUS66 KHNX 101210
Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
410 AM PST Sat Dec 10 2016
.SYNOPSIS...A warm storm system will affect the area through
tonight. The heavier rain is expected north of Fresno and Kings
Canyon with the snow level above 9000 feet. Precipitation could
be heavy at times, especially towards Yosemite National Park. Dry
conditions are likely Sunday and Monday, then precipitation
chances return Tuesday as another storm moves through the area.
.DISCUSSION...Weak shortwave moving through central CA this
morning has provided our area with some light precipitation mainly
from Fresno County northward with mesowest indicating amounts have
generally been a tenth of an inch or less of rainfall. With a warm
airmass prevailing snow levels have been running around 9000 feet
MSL and temperatures have remained mild across the region
overnight following an unseasonably warm day across the area on
The 06Z WRF is indicating a strong shortwave system moving
through central CA this afternoon and evening which has the
potential to bring some significant rainfall to our area with QPF
progs indicating 2-3 inches of rainfall possible for Yosemite
National Park. Further south toward Kings Canyon 1-2 inches of
rainfall are possible with lower amounts further south. Up to half
an inch of rainfall is possible in the central San Joaquin Valley
and a quarter inch in the south valley through this evening. WV
imagery is indicating the high PW moisture associated with this
system is tropical in origin and has streamed northeast from south
of Hawaii in a fast southwest flow.
The WRF and SREF are indicating this system will exit the region
overnight and the precipitation will taper off Sunday morning.
Sunday afternoon through Monday will be dry with above normal
temperatures across our area with shortwave ridging prevailing.
A strong atmospheric river is then progged to push into Norcal by
Tuesday which will result in the potential for periods of rain and
higher elevation snow for central CA through Friday. The models
have been showing very poor agreement and run to run consistency
with the timing and placement of the moisture fetch and there is a
lot of ensemble spread for much of next week which results in low
confidence in the forecast. Thursday still appears to be
potentially the wettest day as a large low pressure system pushes
into Norcal. Ahead of this system, warmer than normal temperatures
will prevail across our area until Thursday. A cooling trend and
increased winds are possible later in the week as heights and
thicknesses lower and onshore p-grads increase.
.AVIATION...For the next 24 hours, across the San Joaquin Valley
and southern Sierra foothills, areas of MVFR and local IFR
possible in low clouds and rain. In the southern Sierra Nevada and
Tehachapi Mountains, widespread MVFR with areas of mountain
obscuring IFR conditions in precipitation. VFR conditions will
prevail across the Kern County deserts.
.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 low.
Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.php for additional information
an/or to provide feedback.