Winter Storm and Debris Flows in California, December 25 to 27, 2019

Area Forecast Discussion
National Weather Service Hanford CA
308 PM PST Wed Dec 25 2019

.SYNOPSIS...A storm system will track across southern
California tonight and Thursday and bring rain and higher
elevation snow to the region. The heaviest precipitation
from this storm will fall in the Kern county mountains and
desert. Thursday night through Saturday night will be dry.
Another storm system could bring a return of wet weather to
the district later in the weekend.

&&

.DISCUSSION...The central California interior is getting a longer
than anticipated respite from wet weather this Christmas day.
Nonetheless, the next storm is still on its way despite the delay.
A cold front well ahead of this storm is currently situated off
the California coast and it will move inland over the district
early tonight with its precipitation. Meanwhile, the upper level
low associated with this system will remain offshore and drift
southward parallel to the central and southern California coast
ovenight. When the low gets south of the Channel Islands, it will
make a left turn at some point and track inland over southern
California Thursday. This is a storm path that will bring
substantial precipitation to southern California during the next
24 hours. Kern county will be on the colder, northern side of this
system tonight and Thursday and will be in a favorable position
to bring heavy snow to the Tehachapi mountains and accumulating
snow or a mix of rain, snow and ice to the Kern county desert.
Snow levels will bottom out between 2500 feet and 3500 feet across
Kern county as the storm tracks by to our south later tonight and
Thursday. Up to two feet of snow is possible from this storm in
the mountains near the Ventura County border during this time.
Travel through the Kern county mountain passes could become very
treacherous after midnight tonight through at least the midday
hours Thursday. In the Kern county desert, frozen precip could
bring a coating of ice and or snow on highways later tonight and
Thursday with very slick driving conditions. If travel is
absolutely necessary in this region, motorists should be prepared
for potentially long delays and the possibility of road closures.
Accordingly, A Winter Storm Warning is in effect for the Kern
county mountains while a Winter Weather Advisory is in effect for
the Kern County desert. Temperatures in this region will probably
rise very little during the day Thursday as well.

North of Kern county, precipitation totals from this storm will
be relatively light. Although winter advisories have not been
issued for the Sierra north of Kern county, a few to several
inches of new snow could fall from this storm system between
midnight and noon Thursday, primarily south of Kings Canyon N.P.

The models move this storm system into southwestern Arizona
Thursday night, by which time all of its precip will have exited
our CWA. In its wake, clouds will linger in the upslope regions
of the district into Friday morning, namely over the south end
and east side of the San Joaquin Valley and adjacent foothills.
Where skies clear in the San Joaquin Valley, fog will inevitably
form toward daybreak Friday. Fog will likely be more widespread
in the San Joaquin Valley Friday night into Saturday morning as
an upper level ridge of high pressure builds over central CA.
Otherwise, Friday through Saturday night will be mostly clear and
precipitation-free with seasonable temperatures.  A light frost
could accompany late night fog in the normally colder locations
of the San Joaquin Valley during this period.

Afterward, the models differ on whether (or not) we get another
episode of wet weather in the 5 to 7 day period. The GFS tracks
another storm down the West coast and into southern California
much like its predecessors Sunday night into early next week.
The ECM forecasts this storm to track more like an inside slider
early next week. If the GFS is correct, rain and mountain snow
will surely return to the CWA but if the ECM is right, our weather
will remain dry in the 5 to 7 day period, so stay tuned.

&&

.AVIATION...MVFR ceilings will persist along the west slopes of
the Sierra tonight with areas of IFR in precipitation between
08z Thursday and 00z Friday. IFR conditions will develop over the
mountains south of Kings Canyon National Park by 06z Thursday with
IFR and mountain obscurations likely over the mountains of Tulare
county and Kern county through 00z Friday. MVFR ceilings are
possible in the Kern county desert between 08z Thursday and 00z
Friday. VFR conditions can be expected elsewhere over the central
California interior during the next 24 hours.

&&

.AIR QUALITY ISSUES...
On Thursday December 26 2019... Fireplace/Wood Stove Burning
Status is: No Burning Unless Registered in Fresno... Kern and
Madera Counties.
Further information is available at Valleyair.org

&&

.CERTAINTY...

The level of certainty for days 1 and 2 is high.
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 until 10 PM PST Thursday for CAZ196-197.

Winter Weather Advisory until 10 PM PST Thursday for CAZ195.

Winter Weather Advisory from 10 PM this evening to 10 PM PST
Thursday for CAZ198-199.

&&

synopsis...Durfee
public...Durfee
aviation/fire wx....MV

weather.gov/hanford