Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
131 FXUS66 KHNX 121835 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 1135 AM PDT Sat Jul 12 2025 .KEY MESSAGES... 1. A Heat Advisory has been issued for the San Joaquin Valley an Sierra Nevada Foothills through early next week. 20 to 60 percent chance for greater than 103 degrees in the Valley today and Sunday; 40 to 70 percent chance for Foothill areas to exceed 100 degrees. 2. Low RH values 15 to 25 percent will stretch across much of the San Joaquin Valley and Sierra Nevada with values 5 to 10 percent in the Mojave Desert this weekend and early next week. RH will increase over the region later in the week with cooling temperatures. 3. 60 to 100 percent chance or temperatures to exceed 105 degrees for much of the Kern Desert over the weekend; 50 to 80 percent chance for Inyokern and Ridgecrest to exceed 110 on Sunday and Monday. && .DISCUSSION... Lots of sunshine today as a ridge of high pressure sits over the West Coast. The position of the high pressure center, just off the California Coast, will lead to triple digit highs and a lack of cloud cover over Central California. Heat Advisory remains in effect across the Central California Interior as afternoon highs will continue to reach into the range of 103-106 degrees. Overnight lows do offer some relief as temperatures bottom out in the mid 60s. Based on the minimal movement of the high pressure ridge, will see several more days of triple digit heat before a potential cool-down around mid-week of next week. The cool-down will be associated with a disturbance riding over the Pacific Northwest on Tuesday and Wednesday. While no precipitation will be associated with the disturbance, winds will see an uptick on Tuesday over the wind prone areas of Central California. Confidence remains high in the current heat-wave as ensemble Probability of Exceedance (PoE) of reaching 103 degrees across the San Joaquin Valley remains in the 50%-80% range through Monday. While Tuesday still shows a range of 50%-80% PoE, that percentage will be for temperatures reaching 100 degrees. Therefore, will maintain the Heat Advisory through Tuesday with high confidence that Wednesday will transition toward below triple digit heat. By mid-week, PoE of reaching 100 degrees falls below 30%, which translates into high in the 90s for the remainder of the period. With the Tuesday to Wednesday time frame as a transitional period from triple digits to 90s, winds will be on the increase. PoE of reaching wind speeds of 40 mph will favor the wind-prone areas of Kern County. Current PoE of 40 mph winds are in the range of 50%-70% over the Mojave Slopes with a few spots reaching PoE of 90%. Will monitor the situation for any possible messaging on this Day 4 to Day 5 event. Otherwise, summer is here as conditions stay from above to near seasonal normal for the period. && .AVIATION... 18Z Update: VFR conditions will prevail for the next 24 hours across the Central California Interior. && .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... Heat Advisory until 11 PM PDT Tuesday for CAZ300>322-324-325- 332. && $$ Public/Aviation/IDSS....Molina/SM weather.gov/hanford