Persistent downpours threaten flooding for the lower Mississippi Valley

A storm that will start by pounding California with waves of heavy rain over the weekend will move into the south-central United States.

The storm will bring moisture with it as it crosses over the Rockies early in the week.

South Central extended regional weather forecast

"The slow movement of the storm and moisture will enhance the risk of excessive rainfall from portions of the southern and central Plains to parts of the lower Mississippi and Ohio valleys," AccuWeather Senior Meteorologist Alex Sosnowski said.

Not only will moisture from this storm bring heavy rainfall, but the storm will also draw the moist and humid air from the Gulf of Mexico.

The combination of these two air masses will significantly increase the chance for flooding downpours into the new week.

From Tuesday to as late as Friday of the new week, waves of heavy rain will continue to deluge eastern Texas, Oklahoma, Louisiana, Arkansas and southern Missouri. By late in the week, the heavy rain will cross the Mississippi River, reaching Mississippi to southern Indiana.

In Little Rock, Arkansas, the average total rainfall for the month of March is around 4.7 inches. In just a few days next week, this amount could be reached or surpassed. Cities like Memphis, Tennessee, and Dallas, Texas, could also have a months worth of rain in only a week.

"Rainfall next week has the potential to approach a foot in part of the lower Mississippi Valley," Sosnowski added. Exactly where the heaviest rain will fall is hard to determine until the storm reaches South Central on Monday.

After days of the rain being stalled in the lower Mississippi Valley, the storm could shift the drenching rain into the Southeast and Northeast by next weekend.