Weeks after Tropical Storm Isaac provided a bit of relief from ongoing drought, the Mississippi River is on a roller coaster ride slipping back toward negative stages.

“We’re still going to stay in the low stages but we will see a few ups and downs,” said Marty Pope, a senior hydrologist with the National Weather Service office in Jackson. “We’re going to oscillate between that zero and 2 foot range.”

The Mississippi River at Vicksburg was at 2.3 feet Friday night, up 0.1 foot from 2.2 feet Friday morning.

Rainfall in Warren County has little to do with the local river stages, Pope said. It’s rainfall in Arkansas, Missouri, and the Ohio River Valley that have the most impact on the Lower Mississippi, he said.

“Right now, luckily, we’ve continued to get rainfall through there. Over the last 14 days days or so we’ve had some rainfall anywhere from an inch to 4 inches over the Ohio River Basin,” he said.

Without continued rainfall, the Mississippi is expected to dip to negative 1.3 feet by Oct. 23, according to the NWS. Through the winter, the country will be entering an El Nino weather pattern, which means a wet winter across the South and an especially dry winter across the Ohio Valley, the weather service predicted.

“We’re really going to need some good rains in the next couple of months before that sets up in that particular area,” he said.

Intermittent rains across the region could influence the river, but not enough to make a major impact, Pope said.

U.S. Army Corps of Engineers officials said they plan to start dredging the Port of Vicksburg Monday, which will be welcome relief for low-water conditions, said Roger Harris senior vice president of operations for Magnolia Marine Transport Co., which is located at the port.

“They’re fighting this battle so far and I think they’re winning and doing a great job with their dredges and such,” Harris said.

Magnolia Marine, which hauls crude oil and other petroleum products, has had to lighten the load of their barge tows by 15,000 pounds less per barge because of the low water, Harris said.

“It’s hurting the bottom line and basically it’s increasing transportation cost of petroleum products, and that in turn is going to be passed down to the consumers,” Harris said.

The shortfall has to be diverted by rail or truck, and it takes about 90 extra tractor-trailers to haul 15,000 gallons, Harris said.

“Those costs are much higher than ours,” he said.

At Vicksburg, a “zero” mark measures out to 46.23 feet deep, the depth of the local gauge above mean sea level. Elevations on the river vary from one station to the next. Any depth below zero is recorded as a negative number. The best way to measure water in the river during low times is to add the official stage to the elevation. Today’s amount would be about 47 feet when elevation is added and last spring’s record flood was 103.33 feet when elevation is added to the official 57.1-foot crest.