Add blazing sun to heavy snowpack, and you get hazardous rivers in Valley below

The extended heat wave the Northern San Joaquin Valley had last week is resulting in more water down this way this week.

The Stanislaus County Sheriff’s Department on Friday issued a warning about the rising level of the Tuolumne River.

“With all the high temps we have had over the last week, there has been an increase in snowmelt into Lake Don Pedro,” the department said on its Facebook page. “This will cause an increase of water flow into the Tuolumne River, raising it from its current level of 51 feet to about 53 feet at the Ninth Street Bridge in Modesto.”

The river rose by Saturday afternoon, and Sunday morning was at 52.3 feet.

“We know it has been hot and the rivers look like a good way to cool down, but we are asking you to please stay out of the water,” the sheriff’s department said. “The river is moving extremely fast and the water is roughly 55 degrees. In some spots of the river, there are high amounts of debris, making them dangerous for people or animals to be in the water.”

In Fresno, the National Weather Service issued a flood advisory for areas along the San Joaquin River from Friant to Mendota through Sunday. The river in the Vernalis area was not expected to reach flood stage, though it is running higher than normal.

Authorities expect the rivers to remain high through at least July.

This story was originally published June 25, 2017 at 4:22 PM with the headline "Add blazing sun to heavy snowpack, and you get hazardous rivers in Valley below."