177 FXUS66 KHNX 271644 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 944 AM PDT Sun Jul 27 2025 .KEY MESSAGES... 1. There is a slight chance (5-20%) for showers and thunderstorms to develop across the Sierra Nevada Crest through this evening, with the greatest chances in the high country of Yosemite National Park. 2. Temperatures return to near or slightly above seasonal averages this week with some fire weather concerns. && .DISCUSSION... The upper-level trough that passed over northern portions of our forecast area will leave with us with a southwest flow aloft for at least the next few days. For today, expect slightly below average temperatures along with a slight chance of Sierra thunderstorms, but today`s highs will be a tad warmer. Breezes will develop once again in the prone areas of near the coastal ranges (50-70 percent chance of at least 25 mph gusts) and along the Mojave Desert slope (50-70 percent chance of 40 mph gusts or stronger) into this evening. The winds continue to produce at least a slight risk for new fires in these areas. Highs near 100 degrees become a possibility in the SJ Valley later this week, including a 15-40 percent chance for Thursday into next weekend. The possibility of triple digit heat remains into the Kern County desert as early as Monday, though with a 10-25 percent chance for areas outside of the Indian Wells Valley (with a much higher likelihood, or around 90 percent). Otherwise, expect mainly seasonal temperatures with highs in the upper 90`s in most valley locations and into the triple digits in the hottest desert locations this week. In the meantime, a slight chance of thunderstorms is in store for this afternoon and early evening, mainly over the Sierra Nevada crest from Yosemite NP to Tulare County. The probabilities shown for today are near 20 percent at Yosemite and lower to around 5 to 10 percent into Tulare County. The best time for storm development will be this afternoon until early this evening. Sierra thunderstorm chances beyond today lower a bit, but we cannot rule out a shower or thunderstorm during sometime this week. Any thunderstorm is capable of producing dangerous lightning; take shelter immediately if thunder is heard. Beyond late next week, a slight tilt in the odds towards below average temperatures, or up to a 40 percent chance, is shown in the latest 6-10 day outlook from the Climate Prediction Center. However, the latest 8-14 day outlook shows up to a 40 percent chance for above average temperatures. For reference, average high temperatures across the Central Valley are in the upper 90`s through the first week of August. && .AVIATION... 18Z Update: VFR conditions are expected in the San Joaquin Valley for the next 24 hours. A 5 to 20 percent chance of thunderstorms will exist across the Sierra Nevada Crest from Yosemite to Tulare County through 03Z Monday. && .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. && $$ BSO/Castro weather.gov/hanford