WARM, DRY WEEK MAY STRESS NORTHERN U.S PLAINS SPRING WHEAT

CHICAGO, June 2 (Reuters) - Warm and dry weather is expected to persist in the northern U.S. Plains Spring Wheat Belt through next week, potentially stressing developing wheat, corn, and soybean crops, agricultural meteorologists said.

“It’s dry for the next 10 days, for the most part,” David Streit, a meteorologist with the Commodity Weather Group, said on Friday. “The complicating factor is a fair amount of heat starting to happen up there as well. That’s going to compound the dryness issue.”

Temperatures should reach the 90s Fahrenheit (32° Celsius) this weekend and again next weekend, Streit said.

Dry conditions have recently intensified in the Dakotas and eastern Montana, even as excessive rains have swamped fields farther south, in the southern Plains and the Midwest.

The weekly U.S. Drought Monitor, prepared by a consortium of climatologists, showed 24% of North Dakota was in “moderate drought” as of May 30, up from 6% a week earlier. Nearly the entire state - 99.9% - was rated “abnormally dry,” up from 44% the previous week.

North Dakota is by far the largest producer of spring wheat, a high-protein variety used for bread and for blending with lower-quality wheats.

Grain traders are monitoring the health of the newly planted spring wheat crop in light of concerns about the quality and protein content of the U.S. hard red winter wheat crop, which is being harvested this month in the southern Plains.

If protein levels in the winter wheat crop are low, millers will turn to spring wheat to boost the quality of their flour blends.

Spot spring wheat futures on the Minneapolis Grain Exchange reached $5.90 per bushel on Friday, the highest since January. The premium for spot spring wheat futures over K.C. hard red winter wheat futures was $1.53 per bushel, the widest since December, underscoring fears about supplies of high-protein wheat.

The spring wheat crop was 96% seeded and 79% emerged by May 28, the U.S. Department of Agriculture said. The government rated 62% of the crop as good to excellent, down significantly from 79% a year earlier.

“Hot and dry weather is not unusual in western North Dakota or Montana, (but) this early is the concern,” Jim Peterson, marketing director with the North Dakota Wheat Commission, said on Friday.

For the most advanced spring wheat fields, Peterson said, “You’re already going to temper your yield potential, even if rains do come later.” BY JULIE INGWERSEN.