textproduct: San Joaquin Valley

KEY MESSAGES

1. Inside-slider storm system tracks into the area this evening into Thursday bringing colder air and chances for light snowfall.

2. Stronger wind gusts anticipated across the Kern County Mountains and Desert from later on Wednesday into Thursday.

3. Areas of Dense Fog returning to the San Joaquin Valley this morning with increasing chances later this week.

DISCUSSION

Satellite and upper-air model data is showing a well defined circulation system southwest of San Diego with a cold disturbance now dropping from the Gulf of Alaska. While the circulation system will draw subtropical moisture into the Desert Southwest, the disturbance dropping toward the West Coast will provide another round of unsettled conditions over Central California. Timing of the next disturbance will have the onset of the more significant portion of the storm reaching Central California between 10PM and 12AM (Midnight). After Midnight, the bulk of the storm enters Central California during the predawn hours as strong winds and light precipitation cross the region. It is during this time from 10PM through 10AM that an inside-slider swings through Central California and ushers in cold air and limited moisture. Probability of reach 4 inches of new snow falls below 10 percent during the storm. Expected snowfall will then in the range from a dusting (Trace) to 3 inches. However, the cold air will allow snow levels initially at 5,000 feet when the storm enters to drop to near 4,000 feet by day-break on Thursday. For the Grapevine (Tejon Pass), a 40 percent probability exist of having snow level at 4,000 feet by 7AM PST on Thursday. With these levels, a dusting of snow reaching Tejon Pass will be observed Thursday morning.

Of concern during the same time, winds expected to pick-up before day-break on Thursday as probability of gusts to 15 mph reach 40-50 percent across the higher terrain and along Interstate-5 by 1AM PST. Percentages increase at 4AM PST with probability of 40 mph winds in the 30-40 percent range across the Kern County Mountains and Desert. Strong winds may peak during the morning hours on Thursday as probability of 50 mph gusts reach 40-60 percent across portions of the Kern County Mountains. Between 2PM and 4PM PST, the percentages drop off as the vort-lobe energy from the inside-slider moves into an area just west of Phoenix. Therefore, will keep the wind highlights (High Wind Warning and Wind Advisory) and issue a Winter Weather Advisory for better snow accumulation across an area from Fort Tejon to Tehachapi during the same time frame as the wind products. By Thursday night, will expect most lower elevation locations to see a drop in wind speeds with lingering Sierra Crest and Mountain ridge-top breezes.

By Friday, ensemble showing high confidence in introducing a high pressure ridge pattern over the West. As the ridge of high pressure moves in, so does the return of fog across the San Joaquin Valley. While some uncertainty exist as we near the middle of the month, the outlook of most of the period from Friday through next Wednesday will see a stagnant weather pattern with fog and possible low clouds lingering for much of the week.

AVIATION

MVFR to VFR will prevail for much of the region over the next 24 hours. Isolated IFR/LIFR conditions for areas of the San Joaquin Valley in dense fog through 21Z Wednesday. A 20-30 percent chance for showers in the foothills and mountains of Kern County between 06Z and 18Z Thursday.

AIR QUALITY ISSUES

On Wednesday January 7, 2026, Fireplace/Wood Stove Burning Status is:

No Burning unless registered in Kern County. Burning Discouraged in Fresno, 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 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

High Wind Warning from 8 PM this evening to 8 PM PST Thursday for CAZ334>336-338.

Wind Advisory from 8 PM this evening to 8 PM PST Thursday for CAZ339.

Dense Fog Advisory until 11 AM PST this morning for CAZ302-303- 306-307-310>312-314-315.