Heavy rain from Hurricane Isaac will stall the harvest of U.S. crops but also add valuable soil moisture ahead of autumn seeding of winter wheat and boost river water levels, aiding waterway transport, an agricultural meteorologist said on Wednesday.
Isaac made landfall early Wednesday and topped a levee near New Orleans, triggering life-threatening flooding seven years to the day after Hurricane Katrina devastated the same area, authorities said.
Global Weather Monitoring meteorologist John Dee said the slow-moving hurricane soon would become a tropical storm and then a tropical depression. It is expected to leave heavy rainfall over a broad expanse of the Deep South and central U.S. Midwest corn-, soybean-, rice-, cotton- and wheat-growing region.
"I don't see it as causing major, major problems," Dee said. "There will be some flooding, and the rains are really too late to help corn or soybean crops."
Meteorologists and other crop experts have said the worst drought in more than 50 years has damaged corn and soybean crops beyond repair.
"From 3 to 6 inches of rain can be expected over the next two to three days in the Deep South and 1 to 3 inches Friday through Sunday in Missouri, Illinois, Indiana and Ohio," Dee said.
Lighter rainfall of from 0.25 inch to 1.00 inch can be expected by the weekend into early next week in far northern areas of the U.S. Midwest, meteorologists said.
Commodity Weather Group said the main threat for flooding and wind damage would be in the cotton, soybean and rice areas in southern Mississippi, southern Arkansas and Louisiana, or roughly the southern third of the Delta during the next couple of days.
Early plantings of crops and a summer of relentless heat and drought pushed crops to maturity, leading to a record or near-record early start for harvesting.
However, harvest has been slowed in the past week due to showers, and only minor progress is expected this week due to the impact of Hurricane Isaac, especially in the central Midwest and Deep South.
The U.S. Department of Agriculture said on Monday that 6 percent of the U.S. corn crop had been harvested and 26 percent of the crop was mature, with most of that in the U.S. South and in the path of the expected torrential rainfall.
The USDA said 8 percent of the soybean crop was dropping leaves or mature, and rice harvest was 27 percent complete. It said 24 percent of the U.S. cotton crop bolls were open and ready for harvest. (Reporting by Sam Nelson; Editing by Lisa Von Ahn)