Flash Flood Warning 16, NWS Hanford, CA

Area Forecast Discussion
National Weather Service San Joaquin Valley - Hanford CA
342 PM PST Wed Nov 28 2018

...Updated Air Quality Section...

.SYNOPSIS...
Heavy snow is expected in the higher elevations of the Sierra
Nevada this evening into Thursday night, while moderate to heavy
rain at times will fall elsewhere. Mud/rock slides or debris flow
is possible in the Sierra Nevada Foothills this afternoon through
Thursday night. Isolated thunderstorms are possible Thursday
afternoon and Thursday evening.

&&

.DISCUSSION...
Winter Weather Warning and Flood Watches remain in effect as the
first in a series of storms hits the area today. Doppler radar
continues to show a band of moderate to heavy rain and snow
centered over Central California. While the intensity has fallen,
gauge reports (along with some reports of mud slides) are still
showing moderate accumulation for the higher terrain. Therefore,
will keep the Watches and Warning in effect as the storm continue
to travel across the district. As for snow, observation from
across the Sierra Nevada continue to indicate snow levels at near
7000 to 8000 feet this afternoon. While snow levels will fall
overnight, after the passage of the weak cold front, most of the
heavier precipitation will have fallen. Therefore, will expect
light snow amounts below the 7000 foot mark overnight. This was
just round one of a series of winter storm to hit the area. More
heavy precipitation events are headed for the district as we
approach the weekend.

Once the first weak disturbance pushes through the area toight,
model show the introduction of a strong jet max driving into
Central California on Thursday. Jet dynamics will be the main
forcing factor for the production of significant precipitation
across the district on Thursday. Presently, model precipitation
rates at the 3 hour interval could reach above 1.00 inch over the
mountains and near a quarter of an inch across the valley. If
these rates can be sustained for even just 12 hours, further
hydrologic concerns can arise for much of Central California.
Based on good model run to run consensus, confidence in a
significant winter storm with higher precipitation rates is high
for the Thursday event. Except for Monday (and possibly Tuesday),
cyclonic flow over the West Coast will keep unsettled conditions
ongoing for much of the forecast period as precipitation lingers
through at least next Wednesday.

&&

.AVIATION...
In the Sierra...Areas of LIFR can be expected in heavier
precipitation through 12z Thursday with mountain obscurations.
In the Sierra foothills...Areas of IFR will occur in heavier rain
this afternoon and tonight. In the San Joaquin Valley...Generally
VFR conditions can be expected during the next 24 hours with areas
of MVFR ceilings and visibilities. VFR conditions can be expected
elsewhere across the central California interior during the next 24
hours.

&&

.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 from 10 PM this evening to 4 AM PST Friday
CAZ096-097.

Flash Flood Watch through Friday morning CAZ093-094.

&&

public...Molina
avn/fw...Molina
synopsis...Molina

weather.gov/hanford