San Diego (CNS)-The National Weather Service issued a flash flood warning for mountainous areas in San Diego County from noon to 7 pm on Sunday.

The National Weather Service said it expects monsoon humidity and daytime high temperatures to increase the likelihood of severe thunderstorms in the mountains on Sunday afternoon.

A weak inverted trough brought widespread showers and several thunderstorms to the area. The forecaster said that the trough of low pressure moved northwest and took away most of the showers.

Most of the rainfall comes from the northern Coachella Valley, southwest across the riverfront and into the northwest of San Diego County.

The high temperature in the coastal area on Sunday is expected to be 75-79 degrees, and the lowest temperature at night is 64-71 degrees. The highest point in the western valley is 84-89, the highest point near the foothills is 90-95, and the lowest overnight is 64-70.

The peak high is expected to be 87-94 and the overnight low is 64-72. The high point in the desert will be 105-110, and the overnight low will be 82-87.

On Monday it is expected that there will be another thunderstorm in the mountains, which will decrease in the middle of the week and then increase again later this week because of the monsoon prevailing around the strong high pressure over the Rocky Mountains.

Expect mild nights and seasonal warm to hot weather throughout the week, as well as higher humidity.

Copyright 2021, City News Service, Inc.