Tornado and Debris Flows in California, February 2, 2019

Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
411 AM PST Sat Feb 2 2019

.SYNOPSIS...
A series of storms will bring hazardous weather to Central
California tonight through Tuesday. The first system moved into
the region overnight and will continue today bringing with it
significant mountain snow, moderate to heavy rain, and strong
winds at times. A second, but colder storm system will affect the
region Monday and Tuesday which will drop snow levels
significantly on Monday. Drier conditions return to the region
by midweek.

&&

.DISCUSSION...
A strong upper low remains about 300 miles west of the SF Bay
Area with the cold front still off the coast. Bands of
light to moderate precipitation have continued to move inland
across central California overnight. Southerly winds have also
increased ahead of this system, especially along Interstate 5
below the Grapevine and up the west side of the San Joaquin
Valley. Expect strong winds to continue in these areas through the
morning and into the afternoon. A high wind warning continues for
the Kern County Mountains where gusts of 70 to 90 mph are
possible. A wind advisory remains in effect for the San Joaquin
Valley where we could see gusts of 35 to 50 mph at times.

As the cold front moves inland this morning, expect precipitation
intensity to increase. The front will move through the CWA around
early afternoon. Winds will decrease after the frontal passage,
but there will be a chance of thunderstorms through the afternoon
and evening hours. In addition to heavy snow in the Sierra, areas
of moderate to heavy rain could cause flash flooding and mud/rock
slides and debris flows, especially over the burn scars.

The upper low will move inland across central California tonight
and early Sunday, but will be followed by another short-wave
trough moving through Sunday night and early Monday, with the
stronger and colder low pressure area dropping south along the
California coast Monday afternoon and moving inland across the
central California Tuesday. This will keep periods of moderate to
heavy snow going in the Sierra Nevada through Tuesday. Snowfall
amounts are still expected to be up to 6 feet through Monday
afternoon with up to another foot of snow expected by Tuesday
afternoon. Snow levels will be around 7000 feet this morning,
lowering to near 5000 feet by this evening. Snow levels will
likely remain between 4500 and 5000 feet Monday then drop as low
as 3000 feet on Tuesday. For the mountains of Kern County, expect
the snow levels to remain above 5500 feet until Tuesday, then drop
to near 4500 feet Tuesday afternoon.

The low will move out of the region Tuesday night with just a few
showers lingering in the Sierra on Wednesday. Dry weather (and
probably Valley fog) is expected Thursday and Friday under a
short-wave ridge. Then the models are indicating another low
pressure system dropping south from the Pacific Northwest and into
California next weekend. The GFS and ECM are not yet in agreement
on the timing and location of this system, but it could bring
some precipitation to the region again next weekend.

&&

.AVIATION...
Areas of MVFR visibility due rain and mist in showers and isolated
thunderstorms. Mountain obscuration across the Sierra Nevada and
Tehachapi mountains during the next 24 hours. Strong gusty winds
+35kt across the Tehachapi Mountains and San Joaquin Valley
through 00z Sunday.

&&

.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...
Winter Storm Warning until 10 PM PST Monday ABOVE 5000 FEET FOR
THE CAZ096-097.

Flash Flood Watch through this evening CAZ093-094-096-097.

High Wind Warning until 4 PM PST this afternoon CAZ095.

Wind Advisory until 4 PM PST this afternoon CAZ089>092.

&&

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