Heat wave is expected to arrive this weekend

Barometric pressure is beginning to build from Southern California and is spreading north. Wind gusts will start to increase, especially at night, further drying out vegetation. Temperature gauges will be rising rapidly.

In short, hot weather will arrive this weekend, according to the National Weather Service, and the heat wave might last several days.

“It’s pretty much the classic fall, critical fire weather pattern that we see this time of year,” meteorologist Ryan Walbrun said Wednesday morning. “When we say we are waiting for fire season, this would be the classic look.”

The heat is expected to settle in by midafternoon Saturday and could elevate temperatures in the far inland East Bay and the South Bay valleys to over 105 degrees by either Sunday or Monday, Walbrun said. Forecasters do not know yet how long the heat wave will last, he said.

Such news is not particularly welcome by fire crews, who have been stretched thin since lightning strikes last month started hundreds of fires throughout the state. Crews have extinguished or fully contained most of those blazes, but wildfires in Big Sur and in Northern California continue their rampage.

The weather service issued a fire weather watch for the North Bay mountains and the East Bay Hills that begins Saturday at 11 a.m. and runs through 8 a.m. Monday. Wind gusts are expected to be between 35 and 45 mph and could reach 50 mph in the highest elevations, according to the weather service.

“Right now, the period of strongest winds will be Saturday night into Sunday night,” Walbrun said. “It won’t really be felt in the valleys. It will be going on in the hills.”

Any threat of fire in the hills has only gone up in the past month, Walbrun said, because vegetation has continued to dry out since the last heat wave just after Labor Day weekend.

“The big deal with these events is that they happen at night, and the winds are going to be strong in the middle of the night,” Walbrun said. “So if something ignites, it’s hard to stay up with it at night.”

Less hard will be staying cool at night, he said.