As the new school year is upon us, local superintendents are telling parents to brace for a drop in upcoming school letter grades for Louisiana's public schools.

The reason for concern is that Louisiana has a new, tougher rating system that will force ratings downward, prompting some education officials to worry that it will spark outcry.

Cade Brumley, the superintendent of the Jefferson Parish School District (the largest in the state), said he's talking to community groups about the shift in the formula. He says other superintendents are doing the same.

The worries stem from major changes in the calculation of school performance scores, which shows how students fared on key tests, graduation rates and academic growth.

The changes are aimed at making student achievement in Louisiana comparable to other states.