Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA

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000
FXUS66 KHNX 190938
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
138 AM PST Tue Nov 19 2019

.SYNOPSIS...
Low pressure will move into the region from the north tonight and
Wednesday bringing a chance of rain and mountain snow along with
cooler temperatures. The low will move east on Thursday with a
return to dry weather.

&&

.DISCUSSION...Water vapor imagery shows a tale to two low pressure
systems along the west coast of North America. A southern low
pressure system is located near 25N/120W and is pushing moisture
northward up the Baja Peninsula. Meanwhile, over the Pacific
Northwest a northern low is moving into Washington with a leading
mid level trough extending into Northern California. Lots of
moving parts to the synoptic pattern to say the least. So how does
this pattern evolve.

I`ll start with the southern low. Models bring this feature
and its moisture northeast into Southern Arizona today and tonight
and for the most part its affects will stay southeast of this
forecast area. As this takes place, the above mentioned low over
Washington moves east and a secondary low forms to its west. This
secondary low is then progged to drop quickly south into northwest
California by late this afternoon and then down the coast to a
position near San Luis Obispo by early Wednesday morning. To this
point, models are very bullish on bringing any precipitation to
the Central California Interior outside of the Central Sierra
where some light precipitation is progged on the northeast side of
the low pressure system.

By Wednesday morning the low is projected to swing southeast
across Point Conception and into the LA Basin. With this track,
the Fort Tejon and Grapevine area could see their first
precipitation and as the flow into the Sierra becomes more
easterly, the crest area will see an increase in snow. By
afternoon the low will eject east towards Las Vegas and some wrap
around snow will continue over the Sierra Crest. Models
(especially the ECMWF) keep some lingering wrap around
precipitation continuing through Wednesday evening before shutting
off rain and snow chances by Thursday morning as the low heads to
the east.

As for precipitation amounts...well you have to start somewhere.
Over parts of the forecast area, especially the northwest areas
little to no rain may fall. Over the east side and south end of
the San Joaquin Valley amounts from just a few hundreths to maybe
a tenth of an inch are likely. Foothills and mountains are now
projected to receive up to 0.50-0.60" especially over higher
terrain. The Kern County Desert areas due to the favorable track
of the low can expect up to 0.20" of rain by late Wednesday night.

And finally, for snow...latest projected snowfall totals of up to
around 10" remain a possibility over the Sierra Crest with higher
elevations of the Kern County Mountains including the San Emigdio
range having the potential for up to several inches above 6000
feet. An early season Winter Storm Warning remains in effect for
these areas.

By Thursday afternoon the low is progged to move east with models
projecting ridging to build in from the north over the weekend.
Early next week models build another blocking "rex block" pattern
over the East Pacific with the storm track remaining to the north.
It won`t take much rain to fall in the SJV to kick off fog season,
so even if just a little rain falls the fog season could kick off
this weekend under the stable high pressure aloft.

&&


.AVIATION...
Areas of MVFR visibilities in haze can be expected
in the San Joaquin Valley with local IFR/LIFR visibilities due
to fog through 18Z Tuesday. VFR conditions will prevail elsewhere
over the central California interior during the next 24 hours.

&&

.AIR QUALITY ISSUES...
On Tuesday November 19 2019... Fireplace/Wood Stove Burning Status
is: No Burning Unless Registered in Fresno... Kern... Kings...
Madera... Sequoia National Park and Forest and Tulare Counties.
Further information is available at Valleyair.org



&&

.CERTAINTY...

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.html for additional information
an/or to provide feedback.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning from 10 PM this evening to 4 PM PST
Thursday for CAZ192-193.

Winter Storm Warning from 4 AM Wednesday to 4 PM PST Thursday
for CAZ194>197.

&&

$$

public...Dudley
aviation....Dudley

weather.gov/hanford


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