The National Weather Service has expanded a Heat Advisory set to take effect on Friday, as temperatures are expected to soar across the Bay Area.

In an update early Wednesday, forecasters placed the Santa Cruz Mountains under the advisory, which already includes the interior valleys of the North Bay and East Bay, along with the Santa Clara Valley. The advisory is in effect from 11 a.m. through 8 p.m. Friday.

Forecasters said high temperatures in some Santa Cruz Mountains communities, including Ben Lomond and Boulder Creek, are expected to reach the upper 90s on Friday. Other inland locations could see highs in the upper 80s to the upper 90s, while high temperatures in far inland locations could exceed 100 degrees.

"Not expecting this to be a record breaking heat event, but some of the hottest temperatures of the year for some locations," the Weather Service said in its forecast discussion posted early Wednesday morning.

Temperatures on Saturday are expected to remain above normal away from the coast, before temperatures cool again on Sunday and early next week.

The Weather Service offered multiple tips to stay cool, including drinking plenty of fluids, staying in air-conditioned rooms if possible and to avoid prolonged periods in the sun.

People are urged to check in on their relatives and neighbors, particularly those who are vulnerable. Drivers are also urged to not leave young children or pets in unattended vehicles.