Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
534 FXUS66 KHNX 151036 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 336 AM PDT Thu Aug 15 2024 && .KEY MESSAGES... 1. Confidence remains high for the stretch of near-normal temperatures for the remainder of this week into the weekend. Below average temperatures are expected for central California on Sunday. 2. A Wind Advisory remains in effect until 5 AM PDT this morning for the Mojave Slopes and Indian Wells Valley. West winds up to 20 to 30 miles per hour and gusts up to 50 miles per hour are expected. 3. Despite relative humidity values improving through the remainder of the week, the risk of grass fires continues with elevated afternoon winds.The risk is most evident in eastern Kern County due to elevated winds and relative humidity less than 10 percent. && .DISCUSSION... Zonal flow remains dominant over central California today in the upper levels of the atmosphere. This pattern is expected to continue through tomorrow afternoon before an upper level trough begins its approach into the Pacific northwest region. Temperatures today and Friday will be near normal, with afternoon highs dropping one to two degrees below average on Saturday, and two to four degrees below average on Sunday. Ensemble guidance from the National Blend of Models suggests only a 10 to 40 percent probability for temperatures to exceed 95 degrees on Sunday for the San Joaquin Valley. This cooling trend is primarily the result of cooler air being wrapped cyclonically around the aforementioned trough from the northern Pacific. Here are the probabilities for maximum temperatures to reach or exceed 95 degrees each day through Monday across the region. Thursday Friday Saturday Sunday Monday Bakersfield 45% 80% 50% 30% 60% Coalinga 75% 80% 35% 15% 50% Fresno 55% 55% 35% 15% 40% Hanford 60% 70% 40% 20% 50% Madera 45% 55% 20% 10% 30% Merced 35% 40% 10% 5% 25% Oakhurst 0% 5% 0% 0% 5% Ridgecrest 100% 100% 100% 100% 100% Visalia 75% 80% 55% 35% 70% This upper level pattern will also cause elevated surface winds each afternoon through much of central California, and especially in the Kern County Desert and Mojave Slopes. Ensemble guidance from the NBM expresses a 30 to 60 percent probability for wind gusts greater than 30 mph each day for this area. A Wind Advisory remains in effect for the Mojave Slopes and Indian Wells Valley until 5 AM PDT this morning due to expected winds 20 to 30 mph with gusts up to 50 mph. Surface moisture will increase across the San Joaquin Valley into the weekend due to the southwesterly flow from the aforementioned trough, with minimum relative humidity rising to 30 to 35 percent by Sunday. While these conditions can help mitigate fire rise, dry fuels remain persistent across central California which, coupled with elevated winds, can cause fires to initiate and quickly spread. Little change is expected for minimum relative humidity in eastern Kern County, with values less than 10 percent anticipated. Despite this initial increase in moisture over the region, drier conditions are expected to propagate into next week as the trough lifts northwards. Extended cluster analysis continues to show favorable model consensus that the aforementioned upper level system will remain off the Pacific coast through Tuesday, continuing the conditions listed above for much of central California. A weaker upper level ridge has the opportunity to build in during the middle of next week, resulting in a slight warming trend; however, indications from NBM ensemble output continue to suggest less than a 40 percent chance to reach or exceed 100 degrees through next weekend. && .AVIATION...Areas of MVFR and local IFR visibilities will continue in and around wildfires. Otherwise, VFR conditions will prevail across the central CA interior over 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... Wind Advisory until 5 AM PDT early this morning for CAZ337-338. && $$ public/aviation...SM IDSS.............VJP weather.gov/hanford