“It’s definitely too late to help corn, and I am not sure about soybeans, but we can definitely use the moisture no matter what,” said Miskus, also an author of the U.S. Drought Monitor, which will be updated tomorrow. “A slow, steady rain would be nice for several days.”
The lack of rain across the Midwest has also caused the shipping channel in the Mississippi River to shrink to where less freight can be carried by barges on the nation’s largest waterway and its tributaries, including the Ohio River.
More than 566 million tons of freight valued at $180 billion moved through inland waterways in 2010, including 60 percent of U.S. grain exports, 22 percent of domestic petroleum and 20 percent of the coal used to generate electricity, said the National Waterways Foundation in Arlington, Virginia.
At 2 p.m. local time, Isaac was about 50 miles (80 kilometers) west-southwest of New Orleans with top winds of 70 miles per hour, 4 mph below hurricane strength.
As Isaac moves north, the amount of rain it brings will fall, said Dan Pydynowski, a meteorologist with AccuWeather Inc. in State College, Pennsylvania. When Isaac leaves Arkansas, it’s forecast to drop 1 to 2 inches in Springfield, Missouri.
The heavy rain expected in Mississippi, Arkansas and Louisiana may be more hindrance than help to farmers, said Joel Widenor, co-founder of Commodity Weather Group LLC in Bethesda, Maryland. Beans, rice and cotton have yet to be harvested.
The rain can hurt the quality of cotton and gusty winds can knock the bolls off the plant, he said.
“If it actually falls off, it may just be a total loss,” Widenor said by telephone.
The rain in Louisiana also won’t affect the Mississippi River because there aren’t any large tributaries in the area to capture the flow, said Jeff Graschel, a service coordination hydrologist at the Lower Mississippi River Forecast Center in Slidell, Louisiana.
“All this rain that we are getting here falls into the Gulf of Mexico,” Graschel said.
Heavy rain draining into the Ohio River is needed to help shippers on the Mississippi. Graschel said that isn’t likely to happen.
“It really does appear it will be a short-term situation and not helping us in the long term,” Graschel said.