High Wind in California, January 25, 2021

Area Forecast Discussion
National Weather Service Hanford CA
342 AM PST Mon Jan 25 2021

.SYNOPSIS...
Precipitation made a return to the region as a disturbance moves
through California. This disturbance brought another round of wet
weather that will continue through this Monday evening. A major
storm system will likely impact Central California Tuesday night
through Friday with widespread moderate to heavy precipitation.

&&

.DISCUSSION...
The next in a series of storm continues to push through Central
California this morning with widespread precipitation. Doppler
radar showing a band of heavier precipitation currently pushing
through over areas south of Fresno County. Based on what has
already occurred, the other area of higher precipitation
accumulation occurred near the foothills of Madera and Fresno
Counties. Radar estimated along rain gauge data have shown values
of a half (0.50) to three quarters (0.75) of an inch so far over
the foothill locations. While the southern band of precipitation
is lighter than the north, additional accumulation will allow that
area to see similar values later this morning. Furthermore, with
the cold air continuing to invade the region behind the cold front
passing through, snow levels will lower to areas that normally do
not see the snow. The biggest impact will be the mountain pass
roads of Interstate-5 and Highway 58 where snow-fall accumulation
will make travel difficult.

In addition to the snow, winds just behind the cold front will
continue to increase as high winds blow over the higher terrain
this Monday. High wind warnings and wind advisories have been
posted for this dangerous situation. Luckily, the path of the
upper level portion of the current disturbance is a coastal one.
Being a coastal hugging disturbance, the bulk of its instability
will remain right along the coast-line. Based on Storm Prediction
Centers day one analysis, agree that convection will mostly remain
west of the district. Yet, will continue to monitor the situation
for any convection that is able to cross the Coastal Range and
enter the San Joaquin Valley today.

By this evening, short range model confidence remains high in
progging the diminishing unsettled conditions and only lingering
showers may continue into early Tuesday morning. Depending on how
quickly winds diminish tonight and if widespread cloud cover is
able to exits the district will we see a very cold night. A hard
freeze watch is currently in place for the San Joaquin Valley from
late tonight through day-break Tuesday morning. While uncertainty
is still a little high, overnight minimum temperatures across the
valley could reach down to 26 degrees-F. A hard freeze occurs
when temperatures fall below 27 degrees.

Looking beyond the short term, longer range deterministic and
probabilistic models have been hinting of a possible atmospheric-
river (AR) event occurring near the mid-week period. While some
uncertainty still exist as to how strong the AR event could
become, many of the ensemble members do point in the direction of
an AR occurring. Therefore, once the current storm exits the
region, the attention will then focus on the significant
precipitation producing storm headed toward Central California.
Currently, uncertainty exist in both the magnitude and timing of
the event that will more then likely enter the district from late
Tuesday to early Wednesday. Statements will be posted soon on what
impacts the AR event may produce once a clearer picture is
resolved on just how far south the moisture will extend during the
AR passage.

&&

.AVIATION...
Widespread MVFR and areas IFR in clouds and precipitation across
the mountains until 06Z Tuesday. Westerly winds will continue to
increase today with gusts reaching 45 knots along the West Side
Hills and gusts up to 70 knots over the mountains and desert.

&&

.AIR QUALITY ISSUES...
None.

&&

.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...
High Wind Warning until midnight PST tonight for CAZ198-199.

Winter Storm Warning until 10 PM PST this evening for CAZ195>197.

Winter Weather Advisory until 4 PM PST this afternoon for
CAZ190>194.

Hard Freeze Watch from late tonight through Tuesday morning for
CAZ180>187.

Wind Advisory until noon PST today for CAZ179.

&&

Public/Aviation/Fire Wx..Molina
IDSS PIO/Social Media....BS

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