The National Weather Service is calling for Friday to start cloudy and then become sunny, with a high near 102 and west winds between 6 and 9 miles per hour.

A heat advisory is in effect from 11 a.m. to 9 p.m. Friday. Heat index values will be as high as 109. The weather service has issued an "excessive heat watch" from Saturday morning to Saturday evening. Heat index values will be up to 100 degrees on Saturday afternoon.

Friday night is expected to be partly cloudy, with a low around 79 and west winds around 5 miles per hour or less. There is a 20 percent chance of precipitation.

Saturday is expected to be mostly sunny, with a high near 99 and south winds between 6 and 9 miles per hour. Heat index values will be as high as 106. There is a 30 percent chance of precipitation.

Saturday night is expected to be partly cloudy, with a low around 76 and northwest winds between 5 and 8 miles per hour. There is a 30 percent chance of precipitation.