FXUS66 KHNX 132011 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 111 PM PDT Sun Oct 13 2024 .KEY MESSAGES... 1. There is a 30-60% chance that visiblities along parts of the 99 corridor will drop below 1/4 of a mile tomorrow morning due to dense fog. 2. Another cooling trend returns by the middle of next week along with a 15-25 percent chance of precipitation. An uptick in winds is forecast along with the cooling trend. 3. The Climate Prediction Center`s (CPC) 6-10 and 8-14 day temperature outlooks have a 33 to 50 percent chance of above average temperatures. && .DISCUSSION... Sunrise surprise dense fog occurred this morning across parts of the San Joaquin Valley, mainly between Fresno and Tulare. Given that RH values in the valley tomorrow morning have a chance of being close to 100% along with light winds, another round of isolated fog cannot be totally ruled out in the same locations. High resolution/HREF guidance indicates chances of visibility dropping below 1/4 of a mile are between 30 and 60% by 8 AM Monday. Outside of potential visibility issues, blended model guidance shows highs trending a degree or two warming tomorrow as a shortwave ridge of high pressure moves over the region. Afternoon highs in the mid 80s continue on Tuesday due to this upper level pattern. Afternoon highs Wednesday and Thursday are projected to trend back downwards as ensemble guidance shows a trough of low pressure moving towards the Great Basin. For our area, this introduces a low chance of precipitation that can accompany "inside-slider" disturbances, with about a 15-25% chance of precip Wednesday evening/night for Yosemite National Park. Afternoon highs are forecast to drop few degrees on Wednesday and again Thursday as the trough moves in, with an increase in onshore flow through the passes on the west side hills. Model guidance shows a decently strong onshore gradient forming over the Kern Mountains, which has the potential to boost winds to Wind Advisory criteria overnight Wednesday. By Friday, afternoon highs are forecast to be the coolest of the week, with highs 70s across the valley. NBM probabilistic guidance shows 50-80% chance that highs across the San Joaquin Valley will be less than 75*F on Friday. Temperatures begin to rebound over the weekend across Central California as the upper low continues to dig southward into AZ, gets cut off, and begins to fill along with high pressure slowing building in the Eastern Pacific. && .AVIATION... Areas of LIFR visibility and ceilings possible in the San Joaquin Valley due to dense fog between 12z Monday and 18z Monday. Otherwise, VFR conditions will prevail across the Central CA Interior over the next 24 hours. && .AIR QUALITY ISSUES... ISSUED: 10/12/2024 13:58 EXPIRES: 10/13/2024 23:59 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... None. && $$ ab weather.gov/hanford