The National Weather Service has forecast that the Mississippi River will crest at Vicksburg and Natchez at the highest levels since 1937.

Forecasts are the river will crest at 53.5 feet in Vicksburg on May 18 and at 60 feet in Natchez on May 20.

On Monday, the river stood at 45.5 feet in Natchez and 39.2 feet at Vicksburg.

The weather service says river levels have risen since heavy rains to the north. Locally heavy rains also are contributing to the rise.

The Mississippi River at Cairo, Ill., at the confluence with the Ohio River, stood at 53.5 feet overnight Sunday, 13.5 feet above flood stage, and it was predicted to crest there May 3 at 60 feet.

In 1937, the Mississippi River topped out at 53.2 feet in Vicksburg. In 2008, the river reached 50.9 feet, the highest since 1973 when it reached 51.6 feet. The benchmark 1927 flood reached 56.2 feet on today’s gauges.

In Natchez, the projected level of 60 feet is almost a two feet above the highest known river stage for the Natchez-Vidalia area, which happened in 1937 when the river rose to 58.04 feet.

In Greenville, the river is expected to crest at 59 feet on May 12. Larry Miller, deputy director of Washington County’s Office of Emergency Management, said about 100 structures would be affected if the river crests at that level.

The high-water event won’t break the levee. Miller said the levee has a flood level of 73 feet.

“The levee will hold back the water,” said Miller. “It is in good shape.”

NWS forecaster Jared Allen said the predicted rise stems from a stagnant storm system in the Ohio and Mississippi River Valleys in the middle of the country.

“There are some very severe and heavy thunderstorms projected for the next three to four days in those valleys,” he said. “We are projecting between eight to 10 inches of rain to accumulate in those days.”

Allen also said storm systems moving through Mississippi and Louisiana this week will also leave help raise the river level.

The weather service said a flood warning was expected to issued Sunday along the Mississippi River and will remain in place until further notice.

In Natchez, city engineer David Gardner said a river level of 59 feet would be expected to cut off access to the Isle of Capri  Casino which is a riverboat sitting in the river below the Natchez bluffs. Gardner said city officials would be meeting with casino officials.

“This happened a few years ago, and we had to shut them down when the river was even lower than it is projected this year,” he said. “That is going to put some major implications on the casino. We are going to be looking at all the different scenarios depending on the river stage. What the city and the casino need to do is safeguard everybody.”

In Vicksburg, precautions also were being taken.

LeTourneau Technologies equipment was being moved to prepare the low-lying oil platform fabrication yard for a repeat of 2008, when the plant shut down for about two months.

“It’s not the first time, but we’re preparing for a flood,” plant manager Bo-D Massey said. “We’re continuing our manufacturing to the best of our ability.”

Eight U.S. Army Corps of Engineers quarter boats were headed upriver to help fight the swelling Mississippi River.

“At the request of the U.S. Army Corps of Engineer Memphis District, the Vicksburg District is going to a section of the Mississippi River at Hickman, Ky., with quarter boats as a precautionary measure to assist in flood fighting,” Corps spokesman Kavanaugh Breazeale said. “The barges will be there if needed.”

The quarter boats, dormitory-style housing and supply areas on barges used by the Corps’ mat-sinking and dredging units, were manned by 30 people. Their initial chore will be to feed and house government officials stationed in Hickman.

Each barge can house up to 100 people, Breazeale said.

The trip upstream to Hickman, which is about 50 miles south of Cairo, is expected to take about five days, Breazeale said.