Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA

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FXUS66 KHNX 171150

Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
350 AM PST Fri Nov 17 2017

.SYNOPSIS...The storm which brought rain and higher elevation snow
to the area on Thursday will move east of the region today. High
pressure will bring drier conditions to the area this weekend.
Another storm will move north of our area on Monday and might
bring some light precipitation early next week.


.DISCUSSION...Rain and higher elevation snow continue to impact
our area as an atmospheric river with deep moisture continues to
drop slowly southward across central CA. Several stations in the
southern Sierra Nevada and adjacent foothills from Fresno County
northward have picked up between 1 and 3 inches of rain since late
Wednesday evening with most of it falling in the past 12 hours.
Rain shadowing due to a fast westerly flow aloft has kept
precipitation amounts lower in the San Joaquin Valley although
several locations in Merced County have picked up between a half
inch and an inch of rainfall. A cold front which was progged to
push through our area early Thursday has just pushed southward
into our CWFA after stalling to our north. This resulted in our
area remaining in the warm sector and mesowest has indicated that
the snow level has remained above 8500 feet for this event
although the higher peaks in the southern Sierra Nevada likely
received several inches of new snow.

IR imagery indicating the main upper low center is now pushing
east across the PAC NW which will finally push the cold front
south across our area today and push the deep moisture fetch
responsible for the moderate to heavy precipitation over the
southern Sierra Nevada southeast of our area later today. The WRF
indicates that most of the precipitation will end by 21Z today
although some lingering showers may persist the the afternoon
hours at the south end of the San Joaquin Valley and over the
mountains. Will extend the Winter Storm Warning currently in
effect for the higher elevations of the southern Sierra Nevada
until 700 am PST this morning as radar composites indicate
moderate to locally heavy precipitation still in progress over
the higher Sierras.

The WRF continues to indicate a ridge building into central CA
tonight and remain over our region through Sunday. This will
result in a drying trend across our area through the weekend.
Inversion conditions over the San Joaquin Valley where low level
moisture will remain from the recent precipitation will favor the
formation of night and morning fog each day with the central San
Joaquin Valley being more favored for areas of dense fog.
Otherwise the weekend will be dry with slightly above normal

The medium range models indicate the next trough moving through
the western CONUS on Monday although the models have been
trending further north with the deeper moisture and the southern
extent of any precipitation from this system with each successive

The 06Z run of the GFS has come more into line with the ECMWF
idea of a stronger ridge over the southwestern CONUS for Tuesday
through next Friday which has been advertised well by the ensemble
means. Confidence has improved for this period and and am trending
temperatures for our area upward with dry conditions prevailing
for our area. Only caveat will be the possible presence of fog,
but with an active storm pattern north of our area as noted by the
IVT progs, there should be enough mixing over our area to limit
the presence of widespread fog.


.AVIATION...Mountain obscuring IFR conditions due to low clouds
and precipitation over the southern Sierra Nevada this morning
becoming mainly MVFR by 21Z today. MVFR in cigs and precip across
the San Joaquin Valley through 21z. Otherwise, VFR conditions will
prevail across the central CA interior during the next 24 hours.





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 for additional information
an/or to provide feedback.


.HNX Watches/Warnings/Advisories...
Winter Storm Warning until 7 AM PST this morning ABOVE 8000 FEET

Flood Watch until 7 AM PST this morning BELOW 7000 FEET FOR

Winter Storm Warning until 7 AM PST this morning ABOVE 7000 FEET



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