Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
014 FXUS66 KHNX 132025 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 125 PM PDT Mon May 13 2024 .KEY MESSAGES... 1. High temperatures will remain well above seasonal values through Saturday. 2. A cooling trend is expected to take place next weekend. 3. A few strong thunderstorms are possible in the Sierra Nevada each afternoon through Tuesday and again next weekend. && .DISCUSSION... Another sunny day across Central California with cloud hugging the coast as the marine layer sits at around 1600 feet MSL. Temperatures under the sunny skies rose to into the mid 90s on Sunday across the San Joaquin Valley with more 90s expected today. Winds on the other hand have remained light under the ridge of high pressure over the West. Yet, with surface pressure gradients from KSFO to KLAS hovering between 5 mb and 7 mb, will expect an afternoon breeze that will diminish after sunset tonight. While convective activity has been minimal over the past two days, a short-wave trof riding over the ridge today will provide Central California with enough lift to fire-up mountain thunderstorms today. The ridge pattern will then rebound toward mid-week as convective activity diminishes ahead of a strong trof that will provide Central California with a significant cool-down next weekend. Probability of Exceedance (PoE) of reaching 90 degress across the San Joaquin Valley is well into the 70 percent range. Even with the passage of the short-wave trof to our north, the disturbance is not strong enough to introduce significant cooling. However, it will stabilize our warming trend and prevent temperatures from rising above the mid 90 range. High- Res Short-range Ensemble convective analysis is placing a significant amount of MUCAPE values across the Sierra Nevada Today. Along with sufficient and lift from the disturbance passage, Probability of Thunder (PoT) is reaching near 40 percent this afternoon which increases the confidence in afternoon convective activity. Yet, PoT drops slighly over the next few days which will keep convection to more isolate coverage. By mid-week, longer range ensemble models show the ridge rebounding as Central California continues to experience high temperatures in the 90s. Ensemble Cluster Analysis continues its trend toward favoring a trof solution next weekend. The break down of the ridge is also reflected in PoE of reaching 90 degrees later next week. Ensemble are showing PoE percentage values dropping going into the weekend with values below 30 percent by Sunday. At this point, uncertainty is high mention organized precipitation out-side of mountain convection next weekend. Currently, based on the ensemble PoE trend, will favor the good cooling Central California will experience early next week. && .AVIATION... VFR for the SJV terminals for the 24 hour cycle. The Sierra UNTIL 03Z Tuesday has an CHC potential MVFR due to thunderstorm development. && .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. && $$ Operational......Molina Support/IDSS.....JPK weather.gov/hanford