High Wind Warning 7, NWS Hanford, CA

Area Forecast Discussion
National Weather Service Hanford CA
1218 PM PST Thu Mar 9 2023

.SYNOPSIS...
A major atmospheric river event will begin to impact the area this
afternoon. Foothills below 5000 feet will see snowmelt and heavy
rain from this storm. Flooding across small and uncontrolled streams
possible. Wind damage may also occur due to the saturated soils and
wind gusts up to 35 mph in the Valley.

&&

.DISCUSSION...
GEFS and European model ensembles are in agreement
of the trough moving in over the Pacific Northwest. Both model
ensembles agree on the positioning and the strength of a westerly
and southwesterly flow aloft. This wind pattern is helping pump
moisture in from Hawaii in an atmospheric river to Central
California. GFS, NAM, and European models all are in good agreement
of Integrated Water Vapor values of 1.34 to 1.38 inches.

The biggest concern with this storm is flooding as snow melt will
happen below 5,000 feet as the snow levels will rise through the
storm from 7,000 feet up to 9,000 feet on Friday. The snow will melt
easily below 5,000 feet as the snow there is almost at 32 degrees
Fahrenheit. THe snow melt as well as the heavy rain expected in the
Sierra foothills will increase the flow into the dams and streams.
Flooding is possible in uncontrolled and small streams from this
increased flow. This rise in flow and the amount of rain from this
storm has necessitated the need of a Flood Watch for the San Joaquin
Valley.

For this afternoon from 4 PM to tomorrow at 4 PM, Fresno and Reedley
have a 86 percent chance of at least an inch of rain. Hanford,
Madera, Porterville, and Visalia all have between a 55 and 65
percent chance of at least an inch of rain in the first 24 hours of
the storm. However, Lemoore, Delano and Bakersfield all have less
than 30 percent chance of at least an inch of rain from 4 PM today
to 4 PM tomorrow. The high probabilities of an inch rain from this
evening to tomorrow is in line with the timing of the storm with the
heaviest being in the first 24 hours.

Winds also will increase as the storm happens this afternoon and
evening. Wind gusts up to 35 mph are expected for the San Joaquin
Valley. These strong wind gusts in addition to the amount of rain
forecast will increase the probability substantially of trees being
knocked over causing property damage.

&&

.AVIATION...
VFR Conditions will be prevalent for Central California. After 0Z,
the San Joaquin Valley can see areas of MVFR conditions in showers
and IFR conditions are possible in mountains due to precipitation.

&&

.AIR QUALITY ISSUES...
ISSUED:  03/08/2023 13:55
EXPIRES: 03/09/2023 23:59
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
and/or to provide feedback.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory from 6 AM to 10 PM PST Friday for CAZ337-339.

Flood Watch from 4 PM PST this afternoon through Sunday morning
for CAZ300>336.

Wind Advisory from 4 PM this afternoon to 4 PM PST Friday for
CAZ300>306.

Winter Storm Warning from 4 PM PST this afternoon to 10 AM PDT
Sunday for CAZ323-326>331.

&&

JPK

weather.gov/hanford