Dense Fog in California, February 15, 2021

Area Forecast Discussion
National Weather Service Hanford CA
330 AM PST Mon Feb 15 2021

.SYNOPSIS...
A cold front will move southward across the district this
Presidents Day with light precipitation expected, mainly over the
mountains, through this evening. Gusty winds will occur in the
wake of this front over the Kern county mountains and desert
Monday afternoon through Tuesday and in the western part of the
San Joaquin Valley Tuesday afternoon. Otherwise, dry weather can
be expected over much of the district this week. High temperatures
will be slightly cooler than normal through Wednesday, then warm
to seasonable levels Thursday.

&&

.DISCUSSION...
Light precipitation is starting to reach the Central California
Interior this morning as the next in a series of storms crosses
the region. The current storm is taking a similar path to that of
the storm that crosses on Saturday. Therefore, while precipitation
will fall across the San Joaquin Valley, the higher accumulation
will occur over the mountainous regions where orographic support
will enhance total precipitation amounts. In addition, a cold
front moving into Northern California this morning will move into
the district later today to support higher precipitation rates and
increase winds. In the meanwhile, the district will reside under
the warm front as noted in the 24 hour change in temperatures. The
region is running some 4 to 8 degrees over this time on Sunday.
This warming air is allowing for higher snow levels as upper air
and radar data are indicating levels near 7000 feet. Therefore,
except for the higher terrain, light rain will be more common this
Presidents Day during storm passage. Based on the current weather
situation, winds will be more of a threat as Advisories are
already posted through Tuesday evening. After today’s storm
passage, ridge will take hold of the West through the end of the
week.

Similar to Saturday’s storm, the current storm is taking an
inside-slider track with the Sierra Nevada being the main focus of
the precipitation. Along with mountainous precipitation, the
storm will move the area of channeled vorticity through the
eastern side of the Central California Interior. The channeled
vorticity will favor winds over precipitation during its passage.
Therefore, Wind Advisories have been issued as speeds could reach
up to 50 mph at its peak. The main focus of the strong winds will
be over Kern County (Mountains and Deserts) and possibly the west
side of the San Joaquin Valley. Model confidence is high that the
passage will occur from during the day and into early Tuesday.
While lingering showers could occur through early Tuesday, models
place the associated cold front well of the district by day-break
on Tuesday as conditions begin to clear out later in the day.

By mid-week, models still progging a ridge pattern shifting over
the West Coast as the cyclonic flow pushes toward the Mid-West.
Therefore, the district is still trending toward a quiet period.
Clearing will be observed going into Wednesday. Thursday will see
a continuation of clear conditions before the next in a series of
storms begins pushing ashore. Confidence is still not that great
going into Friday when precipitation may return to Central
California. Model uncertainty remains high on just how far south
the storm will track as it crosses the West Coast. The bulk of the
storm’s energy will be focused on the Pacific Northwest with
Central California being clipped at its south end. One thing to
note about Friday’s storm is that the origins of the moisture
may be tropical in nature. If models continue to trend in the
current solution pattern, the area may see another Atmospheric
River event by the end of next week.

&&

.AVIATION...
Areas of MVFR with local mountain obscuring IFR conditions will
develop across the Sierra Nevada with the passage of the next
storm. The storm will also likely produce winds in excess of 35
knots through and below the mountain passes of Kern county after
21z Monday. Otherwise, VFR conditions will prevail over the
central California interior during the next 24 hours.

&&

.AIR QUALITY ISSUES...
On Monday February 15 2021...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...
Wind Advisory from noon to 7 PM PST Tuesday for CAZ179-180-182-
183-186-187.

Wind Advisory from 1 PM this afternoon to 7 PM PST Tuesday for
CAZ195>199.

&&

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

weather.gov/hanford