430 FXUS66 KHNX 221920 AFDHNX Area Forecast Discussion National Weather Service Hanford CA 1220 PM PDT Sun Jun 22 2025 .KEY MESSAGES... 1. Major cool down Today with humidities slowly recovering. Better recovery occurring across the Sierra Nevada. 2. A weak disturbance crossing the region on Monday will allow for afternoon convection across the Sierra Nevada from Yosemite down to Fresno County. 3. Warming trend starting on Monday as temperatures return to triple-digit values across the San Joaquin Valley later in the week. && .DISCUSSION... A significant disturbance that produced strong winds and elevated fire weather concerns exits the region as a weaker disturbance is now poised to cross. While the disturbance will have little effect on the winds and temperatures over the region, it will be enough to generate afternoon showers and thunderstorms over the Sierra Nevada Crest from Yosemite to Fresno County on Monday. By Tuesday, zonal flow and weak ridging will allow for a slow warm-up with ever better chances of reaching 100 degrees late in the week. To start, Ensemble Probability of Thunder (PoT) will grow to nearly 20% on Monday across the Sierra Nevada during the weak disturbances passage. Elsewhere, PoT will remain at near zero values during the week. The Sierra Nevada Crest will also drop to very low percentages as the disturbance exits the region on Tuesday and Wednesday. Afterward, the region will be dominated by a developing ridge pattern as dry conditions prevail. Temperatures will start a slowing warming trend and begin reaching toward triple digit values later this week. The first hint toward 100 degree temperatures will be seen on Wednesday as isolated favored locations register with 10%-30% Probability of Exceedance (PoE) of reaching 100 degrees. By Thursday, the PoE grows to near 50% which increases confidence is reaching triple- digit values. While long range ensemble solutions do not hint towards any strong heat-waves, the potential of near triple- digit temperatures exist to keep Central California on the warm side for much of the week. && .AVIATION... 18Z Update: VFR conditions will prevail for the next 24 hours across the Central California Interior. A few clouds building over the Sierra Nevada Crest during the morning hours after 16Z Monday. && .AIR QUALITY ISSUES... ISSUED: 06/21/2025 14:10 EXPIRES: 06/22/2025 23:59 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....Molina weather.gov/hanford