Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
207 FXUS66 KHNX 311912 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 1212 PM PDT Sat Oct 31 2026 && .KEY MESSAGES... 1. Below normal temperatures continue in the near future with localized rain and snow showers (above 8,000 feet) across the area through the early afternoon. 2. More substantial precipitation will move into our area by Saturday evening with a 20-40% chance of at least a half an inch of rainfall from this evening through mid-day Sunday. 3. A Winter Weather Advisory will continue for the higher elevations along the Sierra Nevada mountains with a 15-20% chance of greater than 4 inches of snowfall above 7,000 feet, and a 50-70% chance of greater than 10 inches of snowfall above 9,000 feet through 7am DST tomorrow. && .DISCUSSION... Current satellite shows a large cloud shield off the coast of Southern California moving steadily northeast, which will bring in moderate rainfall for the Valley and moderate to heavy rainfall in the Foothills and lower Sierra, as well as moderate to heavy snowfall for the Sierra above 7000 feet from this afternoon through late Sunday morning. This precipitation is expected to start around 1pm today and continue through the overnight hours, leading to quite a soggy Halloween night for Valley and Foothill residents. The Sierra Nevada, on the other hand, will see snow levels start around 8000 this morning before they drop to around 7000 feet over the course of this system, with a majority of the snowfall occurring above 7500 feet. Total snow accumulations for this system are 4 to 8 inches between 7500 and 9500 feet and up to 18 inches above 9500 feet. Winds as of the latest model runs will only gust up to 35 mph, as this system has most of its energy for producing precipitation. The Winter Weather Advisory issued for the Sierra Nevada will be in effect through 7am PST tomorrow after the bulk of the snow as fallen, though some scattered snow showers may remain after that time. Chances of thunderstorms this afternoon are 10-20%, with the highest chances in western Mariposa County and lesser chances in Kern County and the southeastern Valley. These chances decrease to around 5-10% for tomorrow as much of the moisture as already moved out of the region and colder air replacing it will dampen the uplift potential. Looking to after this system moves out of the area, a brief ridge is expected to move through California, leading to a short warm-up into the low 70`s in the Valley, but after all the rainfall from this system, fog has the potential to develop Monday morning. However, by Tuesday afternoon, another trough has the potential to move through Northern California, though current models don`t show much precipitation with that system, so it is likely much drier than this current system. After that trough moves out, zonal flow may take over before a ridge could begin building over the region by this coming weekend, leading to above normal temperatures. This is also indicated by the Climate Prediction Center for both outlooks, as Central California is under leaning above normal temperatures for days 6 through 14. But there is also leaning above normal precipitation in both outlooks, with a stronger signal in the 8 to 14 day outlook. && .AVIATION... A reduction in visibility to around 4-5 statute miles due to haze is possible tomorrow morning at KFAT, KVIS, and KBFL. Otherwise, VFR conditions will prevail for the next 24 hours. && .AIR QUALITY ISSUES... None. && .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... Winter Weather Advisory until 7 AM PDT Sunday for CAZ323- 326>328-330. && $$ EW weather.gov/hanford