Atwater, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

142
FXUS66 KHNX 042346
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
346 PM PST Sat Jan 4 2025

.UPDATE...Updated air quality issues and aviation sections.

&&

.KEY MESSAGES...

1. There is a 40 to 60 percent chance of quarter mile visibility
or less in the San Joaquin Valley on Sunday morning.

2. Dry conditions and seasonable temperatures will prevail
through most of the week.

3. Confidence increases for a Mono Wind Event Tuesday into
Wednesday with strong winds in the Sierra Nevada with a 45 to 75
percent chance of wind gusts of at least 50 mph.

&&

.DISCUSSION...
We are in a pattern change where the trough that brought rain
to the northern portions of the San Joaquin Valley has slide
well to the east and moving away quickly. In its place we have a
ridge of high pressure which strengthens the next few days
bringing stable conditions to the area. The ridge will help fog
formation tonight with the sinking air that is common in the
trough. There is a 40 to 60 percent chance of quarter mile
visibility or less in fog tonight into Sunday morning.

The big story is Tuesday into Wednesday, as a shortwave trough
develops as an inside slider and slides into southern
California. This trough will lead to a major wind shift with the
upper level winds becoming northeasterly over the Sierra Nevada.
This Mono Wind pattern has become more noticeable and increasing
in confidence by multiple ensembles that they have become
strongly agreed as to the placement of this setup. There is a 45
to 75 percent chance of wind gusts of at least 50 mph over the
Sierra Nevada and into Kern County Mountains Tuesday and
Wednesday. There is a 25 percent chance or less of most of the
Valley receiving gusts above 25 mph on Tuesday and Wednesday.
The winds are forecast to be way above the 20 year
climatological maximums.

The ensembles however diverge over the ridge and trough
beginning Thursday into next weekend. The split in the ensembles
is as to whether the trough will slide far enough south into
Baja California that a rex block forms or if the trough slides
east away from the area. The latest CPC 6-10 and 8-14 day
outlooks favor a 40 to 70 percent chance of above average
temperatures and a 40 to 70 percent chance of below average
precipitation. This is due to models indicating the ridge
continuing to strengthen after the Mono Wind event.


&&


.AVIATION...
00z Update

VFR conditions have established itself in the San Joaquin Valley
for now. MVFR conditions return around 06Z in the Valley and
LIFR to IFR conditions in fog returns beginning around 11Z and
lasts until 18Z. VFR conditions will prevail for the next 24
hours for the Sierra Nevada and eastern Kern County.

&&

.AIR QUALITY ISSUES...
On Sunday January 5 2025, Fireplace/Wood Stove Burning Status
is: No Burning Unless Registered in Fresno, Kern, and Madera
Counties. Burning Discouraged in Kings, Merced, and Tulare
Counties, and Kern (Greater Frazier Park Area) and Sequoia
National Park and Forest.



&&

.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...
None.
&&

$$

public/aviation.......JPK/BSO
idss/pio..............Proton

weather.gov/hanford