Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
866 FXUS66 KHNX 021851 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 1151 AM PDT Wed Jul 2 2025 .KEY MESSAGES... 1. Steady triple digit high temperatures are expected through at least Thursday in the San Joaquin Valley and Kern County desert. A possible cooling trend is indicated in the latest model guidance by Friday and next weekend. 2. Dryness is expected to continue through the next week with steady minimum RH`s in the 15 to 25 percent range in the Central Valley and in the single digits for the Kern County desert. Light winds will keep fire risk low. 3. There is a slight (10-20 percent) chance of afternoon and evening thunderstorms in the higher elevations of the Sierra Nevada until Wednesday. && .DISCUSSION... Upper level disturbance currently over the region and allowing for a southerly surge of monsoon moisture into the Desert Southwest. As of this morning, convection has been firing-up over San Bernardino and Inyo Counties. Will expect the moisture surge to make its way up across the Sierra Nevada Crest with a chance of late afternoon thunderstorm activity from Yosemite down to Tulare and the Kern County Mountains. Will not expect the upper disturbance to effect temperatures or winds in the short term as we continue to see near triple digit temperature values and light diurnal afternoon breezes through Thursday. Friday will see another disturbance move through the area with drop in temperatures and an increase wind desert winds. To start, Ensemble Probability of Thunder (PoT) will grow to nearly 25% this afternoon across the Sierra Nevada. Elsewhere, PoT will remain at near zero values as ensemble instability mean favors the Sierra Nevada Crest this afternoon. By Thursday, the position of the disturbance will be slight more inland and not favoring the Central California Interior (i.e. the Sierra Nevada). Therefore, afternoon today, convection over the region will mark weak with PoT of less than 10%. Temperatures will start a slow cooling trend that will continue through Saturday as Probability of Exceedance (PoE) of reaching 100 degrees drops to less than 10% as max temperatures remain around normal values of mid 90s. While temperatures are not expected to drop much below seasonal normal values, triple digits will have to wait until next Monday when the PoE goes above 20%. These low percentages translate in max temperatures not going much above 100 degrees as PoE of 105 degrees remains at near zero probability for the period (seven days). Winds may become an issue during the next the passage of the next disturbance with cooling will be observed on Friday. At that time, PoE of wind gusts reaching 45 mph sits between 50% and 75%. The higher end percentages represent the Sierra Nevada Crest and the Kern County Desert(Eastern Mojave Slopes). The lower elevations will have the ranges of 20% to 40% for speeds of 45 mph. Yet, for wind gusts of 25 mph, PoE will range from 60% to 80% along the West Side of the San Joaquin Valley, excluding Bakersfield, a good portion the Kern County Mountains and the Sierra Nevada above 5000 feet. Afterward, the disturbance will pass the area and allow for diminishing winds over Central California. && .AVIATION... 18Z Update: VFR conditions will prevail for the next 24 hours across the Central California Interior. A Slight chance (15%-25%) of thunderstorms across the Sierra Nevada Crest until 04Z Thursday. && .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 Weather...Molina IDSS/PIO.......................JPK weather.gov/hanford