More rain is forecast for central Texas a week after flash flooding killed at least 129 people when the Guadalupe River surged 20 feet out of its banks, killing at least 129 people, with 160 people remaining unaccounted. Photo by Dustin Safranek/EPA

July 13 (UPI) — More heavy rain is expected in the Hill Country of Central Texas where flash flooding on July 4 killed at least 129 people, forecasters warned Sunday.

The National Weather Service’s Weather Prediction Center issued a level 3 flash flood alert through Monday morning for the area because of a slow moving weather front dumping rain in northern parts of the Hill Country.

Amid the forecast, investigators suspended their search for victims of the catastrophic Independence Day weekend floods when the Guadalupe River surged more than 20 feet and claimed the lives of at least 129 people. 160 people remain unaccounted for.

There is a 30% to 40% chance of an additional 5 inches of rain in a corridor between the Hill Country and the Dallas metro area in the next 24 hours, forecasters said.

Some flash flooding had already been reported in northern parts of the Hill Country.

The rainfall is not expected to be as severe as the July 4 storms, but because the ground is already saturated, the rain will not soak into the soil, making the region vulnerable to more flash flooding.

“The rainfall amounts of tideway is going to be quick for those soils to saturate and everything becomes runoff,” Orlando Bermudez, a meteorologist with the National Weather Service office for Austin and San Antonio, said.

A flood warning was also in effect for Guadalupe River in Hunt, Texas, about 12 miles from Kerrville, the center of the deadly Fourth of July weekend flooding. Thunderstorms were dumping rain on the region Sunday morning.

More than 20 million people are under flood alerts in an area stretching from New Mexico to Texas, and as far East as Pennsylvania.