textproduct: San Joaquin Valley

UPDATE

Updated Aviation Section.

KEY MESSAGES

1. Winter Storm Warning for Sierra Nevada above 6000 feet from Yosemite to Kings Canyon from early Saturday through Monday morning. Additional rain expected below 6000 feet, with higher amounts mainly Fresno County north.

2. Another band of precipitation arrives later Sunday afternoon and brings significant snow above 6000 feet for much of the Sierra Nevada, including to Tulare County. More widespread rain below 6000 feet, but lighter precipitation amounts over Kern County.

DISCUSSION

Following the departure of this disturbance, a brief lull in precipitation is expected for the first part of the day on Friday. However, another coastal trough will direct waves of precipitation into the region beginning late Friday night and continuing through Tuesday. Latest ensemble guidance shows a 60-80% chance of 1" of precipitation falling across southern and eastern Kern County in the 72 hour period between 12z Saturday and 12z Tuesday, which could reintroduce concerns for excessive precipitation. In the Foothills, there will be a 40-70% chance of 1" of precipitation or more. In the highest elevations, these odds rise to near 100%.

While snow levels are around 8000-9000ft for the New Year's Day system, they will fall closer to 6000ft for this second system, which will result in elevated snowfall amounts in the higher elevations. Confidence has increased enough in snow impacts from the initial wave of this second system to issue a Winter Storm Warning from 09z Saturday to 18z Monday for areas of the Sierra Nevada above 6000 ft.

AVIATION

Areas of shallow fog may form after 12z with light winds and clear skies. Ceilings could drop down to IFR/LIFR conditions and visibilities could drop below 1 SM if fog does form. Skies are expected to clear out after 16z Friday morning.

AIR QUALITY ISSUES

On Friday January 2 2026, Fireplace/Wood Stove Burning Status is: Burning Discouraged in Fresno, Kern, Kings, Madera, Merced, and Tulare Counties, and in 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

Winter Storm Warning from 1 AM Saturday to 10 AM PST Monday for CAZ323-326>331.