Meteorological summer (June through August) began at 12 a.m. Tuesday, and already heat and wildfire concerns in the Golden State are ramping upward. Much of California’s Central Valley from Bakersfield to Redding is under an excessive heat warning, with temperatures in spots expected to spike over 105 degrees. The combination of hot temperatures and low humidity will bring elevated wildfire concerns, jump-starting a season that’s already feared to be worse than normal. It comes amid an “extreme” to “exceptional” drought gripping much of the state in an era characterized by longer fire seasons and more extreme fire behavior.

Longer-range outlooks continue to favor a bull’s eye of anomalous heat parked over the Four Corners region, supporting a prolonged and more severe fire season in the West.

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Forecasters were monitoring the potential for additional wildfires on Tuesday, when temperatures in California’s Central Valley are expected to crest over 100 degrees as the relative humidity falls to between 15 and 25 percent. Triple-digit heat will be widespread in the San Joaquin Valley, the lower foothills and the Kern County desert through at least Thursday, with 90s more probable by Friday. Heat indexes through Thursday could top 110 degrees.

That’s typical early in the season, when high pressure dominates and the jet stream retreats well to the north. Problems arise during the autumn, when the jet stream returns and carries disturbances ashore the Pacific Coast and into the Rockies.