By Sam Nelson
CHICAGO (Reuters) - The first major snowfall of the year and a cold snap set to sweep into the northern Midwest could harm some late-maturing corn and soybeans crops and delay the harvest, an agricultural meteorologist and the National Weather Service said on Thursday.
The storm is centered in a small area across northeastern North Dakota and northwestern Minnesota, including the fertile Red River Valley, where farmers are still harvesting their corn and soybean crops after the worst drought in half a century devastated U.S. grain this year.
Minnesota is the third largest soybean producing state in the United States and the fourth largest corn state, based on its harvest last year. North Dakota ranks number 10 in soybean production.
"There is rain changing to snow in the upper Red River Valley of eastern North Dakota and northwest Minnesota," said John Dee, meteorologist for Global Weather Monitoring.
"It's a small geographical area that grows mainly spring wheat and soybeans," Dee said.
He said from 5 to 8 inches of snow was expected by late Thursday with locally heavier amounts. "It's an isolated storm and unique for this time of year. The snow should begin melting beginning Friday through the weekend," he said.
As of Monday, 36 percent of North Dakota's corn crop had been harvested and 80 percent of the soybean crop had been harvested, according to the state crop progress report.
In Minnesota, 53 percent of the corn crop had been harvested and 76 percent of the soybean crop.
SNOW AND GUSTY WINDS
The U.S. National Weather Service (NWS) on Thursday said that a rapidly intensifying storm is expected to bring snow along with strong gusty winds in northwestern Minnesota today.
Following the storm, cold air will plunge farther to the south and east during the next few days dropping temperatures well below normal especially in the northern high plains and the nearby mountains where light snow is expected to linger, according to the NWS.
Harvesting of the U.S. spring wheat crop is complete and the U.S. Department of Agriculture (USDA) on Monday said 94 percent of the U.S. corn crop was mature, above the 72 percent five-year average and 85 percent of the soybean crop was dropping leaves or mature, above the five-year average of 77 percent.
Corn and soybean crops are well above normal maturity schedules due to early seedings and as the worst drought in more than 50 years pushed each crop to mature status.
Farmers have been harvesting each crop at a record pace based on advanced maturity and the low yields following the drought.
USDA on Monday said 54 percent of the corn crop had been harvested, up from the 20 percent five-year average, and 41 percent of the soybean crop was harvested above the 19 percent five-year average.
Cold weather was moving into the Midwest as well and the first major freeze of the season is expected by the weekend.
"I can't say for sure there won't be any damage at all, there may be some late fields that are damaged, but the majority is mature and this isn't really an early frost anyway," Dee said.
Dee said the cold air mass was moving into the Midwest and roughly the northern two-thirds of the crop region will experience freezing to below-freezing temperatures early Sunday and Monday mornings.
"Temperatures should be in the 28- to 32- degree range (Fahrenheit) in the central Midwest and colder north of there," he said.
Light rains later this week and again late next week will cause minor slowdowns in harvest of the U.S. corn and soybean crops, according to Dee.
"Harvest weather is OK, but not perfect," he said.
Dee said showers of 0.20 inch to 0.60 inch were expected Friday and Saturday in the Midwest with heaviest amounts in the south and east. "A similar amount of rain and in the same locations is likely about mid to late next week," Dee added.
(Reporting By Sam Nelson; Editing by Maureen Bavdek and Sofina Mirza-Reid)