FXUS66 KHNX 240843 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 143 AM PDT Fri Oct 24 2025 && .KEY MESSAGES... 1. Dense fog will occur over the next two nights and morning hours along the Highway’s 41, 99 and 198. 2. A low pressure trough is expected to move through Northern California tomorrow, leading to cooler temperatures and light precipitation to Mariposa County and Yosemite NP. 3. After that system exits the state, warm and dry weather will follow, which would allow or dense fog formation in the mornings next week. 4. The Climate Prediction Center has placed Central California under above normal temperatures and normal for precipitation toward the end of the month. && .DISCUSSION... Building high pressure aloft will allow for dense fog formation this morning in the lower elevations of the San Joaquin Valley, mainly along the Hwy 99, Hwy 198 and 41 regions. A Dense Fog Advisory has been issued for this morning and will be in effect from 5AM through 11AM. During that time, visibilities are expected to be a quarter mile or less, so drive with caution and slow down while in dense fog. This fog may form again tomorrow morning ahead of the incoming trough, as that system isn't expected to come through until later that morning. As this system crosses Northern California Saturday into Sunday, cooler temperatures can be expected across the region, and a small amount of precipitation may fall in the northernmost portion of our CWA, mainly in Mariposa County and Yosemite National Park. Winds will also be elevated, especially along the Mojave Desert Slopes. After the system exits, a warm-up in temperatures is expected through next week, as well as a drying out of the Valley. The calm air at night may also lead to further fog formation just before sunrise through the work week. Looking into the long term, the Climate Prediction Center has put Central California under a 70-80% chance for above normal temperatures for the end of this month and into November. They have also placed this area in a greater than 33% chance for near normal precipitation. && .AVIATION... IFR/LIFR conditions may occur for all TAF sites except for BFL from 12Z through 18Z Friday, then conditions become VFR through at least 12Z Saturday. && .AIR QUALITY ISSUES... None. && .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... Dense Fog Advisory from 5 AM to 11 AM PDT this morning for CAZ301-302-305>307-310-311. && $$ EW weather.gov/hanford