Dense Fog in California, February 7, 2021

Area Forecast Discussion
National Weather Service Hanford CA
359 AM PST Sun Feb 7 2021

...Updated for Dense Fog Advisory in the San Joaquin Valley...

.SYNOPSIS...Dry weather and mild afternoon temperatures can
be expected through Monday. A cold frontal passage Tuesday
will be accompanied by gusty westerly winds through and below
the mountain passes and a slight chance of showers in the
Sierra north of Fresno County. Cooler, wet weather will return
by the end of the week and continue off and on through next
weekend.

&&

.DISCUSSION...Today will turn out to be another pleasant,
day throughout the central California interior. Although dense
fog begins the day in a few areas of the San Joaquin Valley,
we can expect a good deal of sunshine which will again warm
temperatures a few to several degrees above their early
February normals. Little change in the pattern is anticipated
through Monday as skies remain mostly clear. Patchy dense fog
could again materialize in the hours around daybreak Monday in
the San Joaquin Valley. Otherwise, Monday's sunshine will boost
afternoon temperatures well into the 60s in much of the San
Joaquin Valley and lower foothills. In the Kern county desert,
thermometer readings will climb above 70 degrees in most locales
today and Monday.

In the broader synoptic picture, it's a high amplitude ridge of
high pressure anchored over the Eastern Pacific that's been
bringing us the nice weather lately. This ridge will flatten
within 24 hours and a dry westerly flow will reside over central
California Monday through Monday night. An increase in mid and
high clouds Monday night will be the precursors of a generally
dry cold front that will sweep southward through the CWA Tuesday.
If precipitation accompanies this cold front, it will be little
more than just a few showers over the higher elevations of the
Sierra mainly north of Fresno County. Additionally, westerly
winds preceding and following this front will be gusty through
and below the passes on the west side of the San Joaquin Valley
Monday evening and night. West winds will also ramp up through
and below the Kern county mountain passes by Tuesday afternoon
in the wake of this cold front where gusts of up to 45 mph are
possible in the normally windiest locations.  Low clouds could
also form behind this cold front along the valley facing slopes
of the Kern county mountains Tuesday night and linger into
Wednesday morning.

Otherwise, our weather pattern will remain dry Wednesday through
at least midday Thursday as a weak short wave ridge aloft moves
over central California. High temperatures during midweek
(Wednesday and Thursday) will be slightly cooler than they've
been, but still a tad above normal.

The transition to a wet and cooler weather pattern still looks
promising later in the week. The models forecast at least two
cold storm systems to move through the central California
interior Friday through next weekend with rain and higher
elevation snow. The models differ in the timing of these storm
systems which of course makes it difficult to predict when
breaks in wet weather will occur in the 5 to 7 day period.
Nonetheless, we're pretty certain that these storms will deepen
the snowpack over the southern Sierra and beneficial rain will
fall in many lower elevations of the CWA by the end of next
weekend.

&&

.AVIATION...Areas of IFR with local LIFR in fog can be expected
in the San Joaquin Valley between until 17z this morning and again
between 12z and 17z Monday. Otherwise, VFR conditions will
prevail over the central California interior during the next 24
hours.

&&

.AIR QUALITY ISSUES...
On Sunday February 7 2021... Unhealthy for sensitive groups in
Fresno... Kern... Kings and Tulare Counties.  Fireplace/Wood Stove
Burning Status is: No Burning Unless Registered in Kings...
Madera... Merced and Tulare Counties. No Burning For All in Fresno
and Kern 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...
Dense Fog Advisory until 9 am PST...CAZ180-183-185>189.

&&

synopsis...Durfee
public/fw...Durfee
aviation...Andersen
PIO/IDSS...Andersen

weather.gov/hanford