Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
282 FXUS66 KHNX 082249 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 349 PM PDT Fri Aug 8 2025 .UPDATE... Air Quality and Aviation Sections Updated && && .KEY MESSAGES... 1. A warming trend is underway as triple digit heat will be seen through early next week. 2. There is a 10 to 20 percent chance of high temperatures of at least 103 degrees Today before increasing to 40 to 60 percent chance during the weekend. 3. Minor fire risk with widespread minimum relative humidity between 15 and 25 percent for the non-desert areas. Minimum relative humidity expected to be less than 10 percent in the Mojave Desert with breezy winds in the afternoon to evening. && .DISCUSSION... High pressure now becoming the dominate feature over the West as shown in Thursdays max temperatures. Ensemble upper-air analysis has the high showing signs of further amplification today and Saturday as Central California continues its warming trend. Probability of Exceedance (PoE) of reaching 100 degrees across the San Joaquin Valley now sits in the range of 70% to 90% plus between now and Monday afternoon. At the same time, PoE of reaching 105 degrees is still struggling to reach the 50% mark during the next four days with the best chances near Lemoore and the Interstate-5 corridor from Huron southward. Will see little change in the pattern until Tuesday. At which time, a disturbance moving through the Pacific Northwest will introduce a cooling trend as the region returns to near and below normal conditions later next week. Ensemble PoE has been very consistent with the onset of widespread triple digits across the San Joaquin Valley. Now that triple digits are upon us, the heat is on until early next week. Confidence remains high in keeping afternoon max temperatures in the 99 to 105 range during the period as probabilities diminish going outside of that range. By next Wednesday, best probabilities fall in the range between 95 and 100 degrees. Therefore, confidence in a cooling trend next Wednesday to Friday is growing. With the high pressure ridge shifting more off-shore during the weekend and into early next week. The flow aloft remains unfavorable for any Monsoonal moisture surges into Central California through early next week. With flow aloft showing a good westerly component, instability and a lack of moisture will keep any convection at bay as the area remains dry. Longer range ensembles show the same dry pattern through at least next Friday. && .AVIATION... 0Z Update: VFR conditions are expected in the San Joaquin Valley for 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...Molina aviation....JPK weather.gov/hanford