The supply scenario for corn and wheat just got tighter. In its monthly World Supply/Demand (WASDE) report, USDA lowered both wheat and corn stocks based on inclement crop weather in key areas for both crops. The corn number is especially bullish, sending all grains higher Thursday.

Read more USDA bullish corn, traders say

More discussion on current grain stocks

• 'Extremely uncomfortable with grain markets'
• Flooding reduces corn plantings, output
• VIDEO: Supply scenarios
• Also: Markets failing to digest all crop weather
• Analysis: What crop disaster?

Grain stocks worries are enflamed by continued severe weather and conditions that are hampering planting and crop progress in parts of the Midwest and northern Plains. Farmers from central and eastern North Dakota to the Missouri River Valley in Nebraska and Iowa are fighting rising waters that endangers thousands of acres of crop land.

Read more: Farmers fighting the flood in SW Iowa
Slideshow: ND flooding aerial tour