Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
755 FXUS66 KHNX 231855 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 1155 AM PDT Sun Aug 23 2026 .KEY MESSAGES... 1. Triple digit heat continues for San Joaquin Valley and Mojave Desert. 50 to 60 percent for Major Heat Risk in the Southern San Joaquin Valley at the start of this week. 2. A 5 to 15 percent probability for extreme heat in the Mojave Desert toward the end of the week and starting September. && .DISCUSSION... Upper level disturbance continues to swing around the ridge pattern today and crossing over the Northern Rockies. With its current trajectory, the disturbance will move into the Upper Mid-West on Monday as the Ridge rebounds over the West Coast. 24 Hour change in temperatures already running slightly higher from Saturdays cool-down. Will expect a return of triple digit heat today with further heating on Monday as the exiting disturbance allows for more amplification of the Ridge on Monday. A look at the Probability of Exceedance (PoE) of reaching 100 degrees has much of the San Joaquin Valley ranging from 65 to 85 percent from Fresno To Bakersfield, respectively. North of Fresno County, the PoE range is more in the range of 45 to 65 percent. On Monday, those percentages go up to 85 to just above 95 percent. Therefore, the peak heating occurs on Monday (when widespread Moderate Heat Risk is occurring) with a drop off in the heat toward the end of the week. Also noted is a patch of Major Heat Risk over West Kern County on Monday. Furthermore, while probabilities are running high, the PoE of reaching 105 degrees is rather low with Bakersfield at 35 percent on Monday. Therefore, will confine temperatures values near 105 to the lower elevations of Kern County. With the flow aloft turning more westerly and expected to maintain its westerly component, the surge of monsoonal moisture will continue its eastward trend as probability of thunder diminishes in the coming days. While a 5-10 percent chances does exist this Sunday across the Sierra Crest, the next several days show lower probabilities for the same area. Therefore, hot and dry expected for much of this week. && .AVIATION... VFR conditions prevailing 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... None. && $$ Public/Aviation....Molina weather.gov/hanford