* Some planting in east this week
* Five to seven day planting window next week
* Best opportunity to plant corn/soy this season
By Sam Nelson
CHICAGO, May 8 (Reuters) - Better corn planting weather is expected in the U.S. Midwest over the next week to 10 days following wet weather that has hampered the seeding pace to the slowest in nearly three decades, an agricultural meteorologist said on Wednesday.
"There definitely will be better conditions than we've had, the best opportunity will be this weekend through early next week," said Andy Karst, meteorologist for World Weather Inc.
Karst said some corn planting would be taking place today and Thursday in the eastern Corn Belt while rains kept planting at a minimum in the west.
"There will be some showers in the west Wednesday through Friday. There also will be some showers later next week but they'll be light," he said. "By far, this is the best planting opportunity we've had this season."
Commodity Weather Group (CWG) on Wednesday said rains would spread from Kansas to Michigan over the next three days, slowing corn and soybean plantings.
However, there should be a minimum of five to seven days of good planting weather in many areas of the Midwest beginning this weekend, according to CWG. "Planting progress should remain well behind normal but improve," said CWG meteorologist Joel Widenor.
Stalled by rain and late-season snow in the last week, U.S. farmers had planted just 12 percent of their intended corn acres as of Sunday, the slowest pace since 1984, the U.S. Department of Agriculture said in a weekly report on Monday.
Soybean planting was 2 percent complete by Sunday, tied with 1983 and 1993 for the second-slowest place by early May, following the 1984 record of 1 percent.
The five-year average for planting progress at this time of year is 47 percent for corn and 12 percent for soybeans.
Producers working fields in the heart of the U.S. Corn Belt were interrupted by storms at mid-week.
Seeding progress fell short of trade expectations, including a Reuters poll of 14 analysts ahead of USDA's report that pegged corn planting at 15 percent complete.
For U.S. farmers waiting through the worst delays to corn planting in 29 years, it is not time to panic.
"We will get it planted," said Gordon Wassenaar, a farmer in central Iowa who has not been able to start planting yet due to wet fields. "It is not that late yet."
Farmers, many of whom are facing the prospect of reduced yields at harvest if they do not finish their planting in the next 10 days, can quickly cover huge swaths of corn acreage. Forecasts for clear skies in the next week have bolstered their confidence about getting back on schedule.
U.S. grain prices have fallen during the past week, reflecting expectations that farmers will plant their corn acreage - forecast to be the biggest since 1936 - in a timely matter. (Additional reporting by Julie Ingwersen and Mark Weinraub in Chicago; Editing by Nick Zieminski)