More triple-digit heat is expected this weekend, with highs hotter than 100 degrees forecast for Sonora and up to 105 for places like Moccasin, Chinese Camp, Copperopolis and San Andreas.

That means there will be the usual potential for explosive fire starts, moderate risks of heat-related illness for sensitive groups including the very young and elderly, as well as the likelihood of heat stress for pets and livestock.

Relief with temperatures 30 degrees to 40 degrees cooler will be within reach at pass elevations and other locations in the High Central Sierra.

Some local waterways in the Mother Lode are still tapped directly into Central Sierra snowmelt so they will be running cold and fast and strong enough to kill people. Other watersheds have melted out, and creeks and streams in some lower-altitude areas are mild and temperate, perfect for wading, dipping and swimming.

Up at elevations like Hetch Hetchy and Yosemite Valley, daytime highs are expected in the low to mid-90s with chances of afternoon thunderstorms possible each day.

Relief at higher elevations

Higher places like Tuolumne Meadows, Tioga Pass, Sonora Pass and Ebbetts Pass can expect daytime highs in the 60s and 70s, with more chances of afternoon thunderstorms and overnight lows in the high 30s to low 40s.

Forecasters with the National Weather Service in Sacramento say they have high confidence in their predictions for hot temperatures in the Mother Lode foothills this weekend.

Overnight low temperatures are expected to remain in the 60s Friday night, Saturday night and Sunday night in foothill towns.

As of Thursday afternoon, there were no heat advisories in place for Calaveras or Tuolumne counties. Triple-digit heat is normal during summer months in the Mother Lode.

For San Andreas, Angels Camp and Sonora, daytime highs are expected to ease into the high 90s by Monday.

Contact Guy McCarthy at gmccarthy@uniondemocrat.com or (209) 588-4585. Follow him on Twitter @GuyMcCarthy.

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