Atwater, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

195
FXUS66 KHNX 211731
AFDHNX

Area Forecast Discussion
National Weather Service Hanford CA
930 AM PST Sat Dec 21 2024

.UPDATE...
Updated the Aviation Section.


&&

.KEY MESSAGES...
1. Dense Fog Advisory in effect until 10 AM PST this morning.

2. There is a 10 to 20 percent chance of 0.05 inches or more of
rain Saturday into Sunday for most of the Valley with a 50 to 70
percent chance for Merced and Mariposa.

3. There is a 20 to 50 percent chance of a dusting of snow above
7,000 feet today. Tioga Pass and Tuolumne Meadows have a 10 to
20 percent chance of 4 inches or more of snow.

4. Tuesday has a 45 percent or greater chance of quarter inch of
rain or more for the San Joaquin Valley north of Bakersfield.

5. There is a 30 to 60 percent chance of 8 inches of snow or
more above 7,000 feet in the Sierra Nevada from Tuesday into
early Wednesday morning.

&&

.DISCUSSION...

This morning, we have a Dense Fog Advisory until 10 AM. However,
the fog has been reluctant to dissipate so there is potential
for it to be extended. Latest probabilities have a 60 percent
chance or greater of high temperatures at or above 65 degrees
today. However, the high temperatures have been below the
ensemble means due to the persistent fog thanks to the ridge
overhead.

However, model ensembles agree that the ridge weakens a bit and
moves east today with a shortwave trough slides across northern
California into Oregon. This trough brings rain and snow
potential to the San Joaquin Valley and Sierra Nevada this
afternoon through tomorrow morning. There is a 20 to 50 percent
chance of a dusting of snow for the Sierra Nevada from Fresno
County northward with a 10 to 20 percent probability of 4 inches
of snow at Tuolumne Meadows and Tioga Pass. In the Valley, there
is a 10 to 20 percent chance of 0.05 inches or more for most
locations with Merced and Mariposa Counties seeing a 50 to 70
percent probability.

Ensembles have the ridge reestablishing Sunday into Monday. This
will help with fog formation for both days. However, a bigger
trough moves in on Tuesday bringing better chances of rain and
snow. There is a 30 to 60 percent chance of 8 inches of snow or
more above 7,000 feet for the Sierra Nevada with this storm.
Down in the Valley, there is a 45 percent probability and
greater of quarter inch or more of rain.

The latest ensembles also have another small ridge late
Wednesday after the trough lifts. Thursday brings another trough
with another chance of rain and snow. However, the ensembles
diverge as to whether the trough will become an inside slider
resulting in stronger winds. The CPC 6-10 day outlook has a 33
to 60 percent chance of above average precipitation with a 60 to
70 percent chance of above average temperatures. This outlook
indicates a very warm moist pattern. The 8-14 day outlook has a
49 to 50 percent chance of above average temperatures with a
gradient from a 33 to 40 percent chance of above average
precipitation in Merced and Mariposa Counties to a 33 to 40
percent chance of below average precipitation in Kern County.

&&


.AVIATION...
18Z Update:

San Joaquin Valley and West Side Hills: Mainly IFR until 19Z Sat,
with areas of LIFR in fog. After 18Z Sat, mainly MVFR in mist and
haze with areas of IFR in mist and haze until 06Z. After 06Z Sunday,
IFR to LIFR conditions return with fog.

In the High Sierra/Foothills, MVFR to IFR conditions possible
after 00Z due to showers and clouds. Otherwise, VFR conditions
will prevail.


Kern County Desert and Tehachapi Mountains remains VFR for the
24 hour period.

&&

.AIR QUALITY ISSUES...
ISSUED:  12/20/2024 15:21
EXPIRES: 12/21/2024 23:59
On Saturday December 21 2024,  Unhealthy for Sensitive Groups in
Kern County.  Fireplace/Wood Stove Burning Status is: No Burning
For All in Kern County. No Burning Unless Registered in Fresno,
Madera, and Tulare Counties. Burning Discouraged in Kings and
Merced Counties, and Kern (Greater Frazier Park Area) and Sequoia
National Park and Forest.



&&

.CERTAINTY...

The level of certainty for days 1 and 2 is medium.
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...
Dense Fog Advisory until 10 AM PST this morning for CAZ301>303-
305>307-309>312-314-315.
&&

$$

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

weather.gov/hanford