Includes Yosemite National Park and Oakhurst
July 1, 2021 - The National Weather Service Hanford Office reports a few strong thunderstorms are possible in the Sierra Nevada and adjacent foothills this afternoon into this evening. Dangerous cloud to ground lightning strikes, localized flooding, small hail, and wind gusts near 45 mph are hazards associated with strong thunderstorms.
Area Forecast Discussion National Weather Service Hanford CA 305 AM PDT Thu Jul 1 2021 .SYNOPSIS... High temperatures will be around the century mark in San Joaquin Valley Thursday into early next week. Moisture aloft will continue to allow for a chance of thunderstorms over the Sierra Thursday however a turn to a more southwest flow on Friday and Saturday will diminish the threat. && .DISCUSSION... After another active day of convection across the Sierra Nevada, local radar is free of echoes and satellite imagery showing just some residual clouds now. Elsewhere, temperatures climbed to well above normal again with widespread triple digit highs across the San Joaquin Valley, Sierra Foothills, and Kern County Desert. A couple high temepratures of note were 108 degrees at Three Rivers and Taft, and 107 degrees at Lemoore. The strong ridge of high pressure responsible for the heat wave over the last several days is weakening a little and shifting east. Temperatures are forecast to lower slightly today but will remain several degrees above normal. Most of the SJ Valley is expected to top out around the century mark today. But a little onshore flow should hold parts of Merced and Madera County in the mid to upper 90s. The National Blend of Models shows little changes in temps from today through the weekend. With monsoon moisture in place, daytime heating will trigger another round of afternoon showers and thunderstorms over the Sierra Nevada. Some drier air in southwest flow aloft will keep convection north of Kern County with the thunderstorm threat mainly from Yosemite NP to Sequoia NP. Light steering flow will cause slow moving storms and the potential for localized heavy rainfall to occur. Further drying of the airmass from the south will occur on Friday. A few showers and thunderstorms will remain possible around Yosemite NP on Friday afternoon. Models are showing a little surge of mid- level moisture from the south on Saturday for a possible uptick in the coverage of convection across the Sierra. That moisture dwindles on Sunday for one more day of Sierra convection. Model ensembles agree with a high pressure cell developing over the climatologically favored Four Corners region early next week. This high may strengthen and build westward over southern California by midweek for another warming trend towards well above normal temps. && .AVIATION... VFR conditions will prevail throughout Central California this morning. MVFR/IFR conditions in and near scattered showers and thunderstorms over the Sierra Nevada and adjacent foothills from 19z this afternoon until 03z this evening. && .AIR QUALITY ISSUES... On Thursday July 1 2021...Unhealthy for sensitive groups in Kern and Tulare Counties and Sequoia National Park and Forest. Further information is available at Valleyair.orgSource: NWS
