textproduct: San Joaquin Valley

UPDATE

Updated Aviation Section.

KEY MESSAGES

1. Above average temperatures continue across the region. Low minimum relative humidities, especially in the Sierra Nevada.

2. Precipitation chances will return next weekend.

3. Slight chance for morning fog in the northern San Joaquin Valley Monday.

DISCUSSION

Much like was indicated last night, there are few changes in the large- scale synoptic pattern for the start to the week. High pressure remains in place over central and southern California, directing much of the prevailing atmospheric flow to the north through the Pacific Northwest and Northern Rockies. For the local area, this pattern will mean a continuation of clear skies and above average temperatures. Also anticipated are dry conditions with low minimum relative humidity values between 15 and 25 percent in the Sierra Nevada above 3,000 to 4,000 feet. However, the subsequent temperature inversion set up over the region will trap moisture in the San Joaquin Valley, resulting in minRH values near 40 percent in the afternoons, but with overnight recoveries approaching 100 percent. In locations where the air reaches saturation, there are chances for fog to develop, the highest potential being in the rural areas between California State Route 99 and US Interstate 5. For Monday, high resolution ensemble guidance expresses a 30 to 40 percent chance for patches of quarter-mile visibility. Though, chances increase for Tuesday morning, especially for the north valley areas, as dew point temperatures increase across the region. The rise in dew points is attributed to a weak shortwave trough scraping through northern California which will pull moisture into the central California interior while morning lows remain largely the same.

This trough will be short lived, with high pressure building in again on Wednesday, warming temperatures near ten degrees above average again towards the end of the week. Most of the southern San Joaquin Valley has a 40 to 50 percent probability to exceed 80 degrees on Thursday, with some locations nearing one to two degrees from record highs.

A pattern change looks to be in store beginning Friday as a cutoff low pressure system tracks to the south through Baja and Southern California, though there are weak probabilities (less than 10 percent) for measurable precipitation with this first system. Rainfall potential increases through the weekend as a more robust longwave trough pushes through the Pacific Coast late Saturday into Sunday. Ensemble guidance highlights a 60 to 70 percent probability for a wetting rain (>0.10") to occur on Sunday across the majority of the local warning area. Snow levels are still expected to be near 6,000 feet with this second system, with 48 hour snow totals approaching 5 to 10 inches, especially in the central Sierra and at higher elevations.

AVIATION

VFR conditions expected across the valley areas through 12Z Mon, after which patches of MVFR to IFR conditions will begin developing, especially in the rural areas of the region. However, MVFR to VFR conditions will return starting around 18Z. For the Sierra Nevada and Mojave Desert, VFR conditions will be present for the next 24 hours.

AIR QUALITY ISSUES

ISSUED: 11/08/2026 14:49 EXPIRES: 11/09/2026 23:59

On Monday November 9 2026, Fireplace/Wood Stove Burning Status is: No Burning Unless Registered in Fresno, Kern, Kings, Madera, Merced, and Tulare Counties. Burning Discouraged 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

None.