Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
262 FXUS66 KHNX 152335 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 335 PM PST Mon Dec 15 2025 .UPDATE... Aviation and Air Quality Sections Updated. && && .KEY MESSAGES... 1. Fog, while dense at times, and low clouds will continue each night and morning across the San Joaquin Valley into the foothills up to 1,500 feet through Tuesday. 2. Above average temperatures will continue across the mountains and desert until Tuesday, as the high pressure pattern persists over the region. 3. Precipitation makes its return to Central California by the middle of the week after having a dry start to December, with a more substantial pattern change by this weekend through the Christmas holiday. && .DISCUSSION... The consistent stable pattern over the southwest will continue through at least the beginning of next week, with strong ridging keeping the low stratus clouds in place for the center of the San Joaquin Valley with dense fog on the edge of the Valley from elevations of 500 feet to 1500 feet. This stratus will also lower further down during the nighttime hours and lead to fog in the Valley itself. A small pattern change is likely in store for Central California, with the ridging over the Southwest weakening somewhat as a small trough passes through the Pacific Northwest. This weaking may lead to slight troughing in Northern California into Central California, which may lead to a small amount of precipitation for the northern-most Counties in our CWA, mainly in Mariposa County and Yosemite Nation Park. This small disturbance may also provide elevated winds aloft to break the inversion over the Valley and lead to the stratus deck clearing out, though it`s unclear if those winds will be strong enough. Confidence has increased for a more significant pattern change for Central California this weekend into next week, with the ensemble models consistently showing a large trough moving through the west coast by this Saturday through the 26th of December. The Climate Prediction Center has also highlighted the 22nd of December through the 26th for a high risk (>60%) of heavy snow in the Sierra Nevada, and moderate risk (40-60%) of heavy precipitation for the Sierra Foothills and Coastal Range for the 23rd through the 25th. && .AVIATION... IFR to LIFR ceilings and visibilities are expected to prevail for much of the San Joaquin Valley during the next 24 hours, with a 50 to 70 percent chance of VLIFR in dense fog between 06Z and 19Z Tuesday. IFR to LIFR conditions will also persist in the coastal ranges, Sierra foothills, and the Kern County mountains due to low clouds. Otherwise, VFR conditions will prevail in the Sierra Nevada and in the Kern County mountain and desert areas over the next 24 hours. && .AIR QUALITY ISSUES... ISSUED: 12/15/2025 15:26 EXPIRES: 12/16/2025 23:59 On Tuesday December 16 2025, Fireplace/Wood Stove Burning Status is: No Burning Unless Registered in Fresno, Kern, and Madera Counties, and Kern (Greater Frazier Park Area). Burning Discouraged in Kings, Merced, and Tulare Counties, 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... None. && $$ public...EW aviation....JPK weather.gov/hanford