Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
020 FXUS66 KHNX 122010 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 110 PM PDT Sun May 12 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...An upper ridge is now centered over central CA and providing our area with dry conditions and above normal temperatures. Temperatures are currently running 3 to 5 DEG F above yday at this time across most of our area. The ridge is progged by the SREF to shift into the Great Basin region on Monday which will allow for a return east to southeast flow to develop aloft over central CA. While there is a slight chance of afternoon and early evening thunderstorms over the Sierra Nevada today, chances will be higher on Monday as the pattern aloft with an offshore flow will be more favorable for convection and some cooling aloft will result in more instability over the Sierra Nevada. Latest NBM probabilistic guidance is indicating the following probabilities for thunderstorms on Monday afternoon in the Sierra Nevada and adjacent foothills: Tioga Pass: 28% Tuolumne Meadows: 27% Yosemite Valley: 21% Wawona: 18% Lake Thomas Edison: 27% Oakhurst: 13% Shaver Lake: 18% Grant Grove: 18% Three Rivers: 17% Although instability will be less prevalent over the Sierra Nevada on Tuesday and Wednesday, there will be a slight chance of afternoon and evening thunderstorms on Tuesday and a few showers on Wednesday as the flow aloft slowly turns more northerly and the mid levels dry a bit. Another ridge will build into the PAC NW and Norcal between Wednesday and Friday which will bring warmer and drier conditions aloft which will inhibit convection along with providing for slightly warmer temperatures across our area on Thursday and Friday. Ensemble means are showing a split trough moving through the western CONUS next weekend which will provide for enough instability and lift for a isolated afternoon and early evening thunderstorms over the Sierra Nevada and will also bring a cooling trend to our area with temperatures lowering to a few degrees above normal by next Sunday. && .AVIATION... Areas of localized MVFR due to thunderstorm activity possible from thru 03Z Mon and again after 18Z Mon in the Sierra Nevada. Otherwise, VFR conditions will prevail across the Central CA interior for at least 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/fire wx...DAS idss...Molina weather.gov/hanford