Area Forecast Discussion
Issued by NWS San Joaquin Valley, CA
Issued by NWS San Joaquin Valley, CA
929 FXUS66 KHNX 040456 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 957 PM PDT Tue Jun 3 2025 .UPDATE... Aviation updated. && .KEY MESSAGES... 1. Minor Heat Risk is expected in the San Joaquin Valley through Thursday before Moderate Heat Risk returns on Friday into early next week. 2. There is a 15 to 30 percent chance for thunderstorms in the Sierra Nevada mountains each afternoon today and Wednesday, with the Storm Prediction Center issuing a General Risk for thunderstorms in the mountains for both of those days. 3. Breezy winds can be expected in the mountain and desert regions today, due to a disturbance located over the Southwest. && .DISCUSSION... Chances for thunderstorms in the Sierra Nevada continue to exist through the week, especially today and tomorrow with chances of 15 to 30% in the late morning to evening. Any thunderstorm that develops has the potential to drop localized heavy rainfall and frequent lightning strikes. Thunderstorms may continue to develop each afternoon through the weekend, though the chances are slightly lowered compared to today and tomorrow at 10 to 20%. While these storms are being fueled by mid level moisture, the moisture closer to the surface continues to be dry, with minimum relative humidities in the Valley remaining around 20-25%, with up to 30% closer to the Foothills. Taking a look at temperatures for the next week, highs today are expected to be only slightly above normal as the low pressure disturbance over the California coast will keep 500mb heights lower than they would be under a ridge. The extra clouds and moisture will also help cool the air aloft. As that disturbance moves to the east, the larger trough it was embedded in doesn`t have the same amount of energy and highs will increase a few degrees from today to tomorrow. The warming trend is expected to continue through the weekend as a weak ridge builds into the Southwest, leading to a possible return to triple digits, though current models indicate temperatures are not likely to increase past those numbers. There is also the possibility for a slight cooling trend by next Tuesday, with the Euro ensemble showing a shortwave trough infiltrating the ridge above the west coast. && .AVIATION... 06Z Update: VFR conditions will prevail for the next 24 hours across the Central California Interior. A 15-30 percent chance of thunderstorms exists in the Sierra Nevada from 18Z Wed through 03Z Thu. && .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...EW aviation....BSO weather.gov/hanford