It's clear that tornadoes caused significant damage across eastern Nebraska this weekend but the expert assessment of the storms won't be complete until at least Tuesday. 

The National Weather Service sent crews of storm experts out Monday to look at the damage Sunday's storms left behind but the crews weren't able to survey all the damage.  The Weather Service and the Nebraska Emergency Management Agency say it is clear Sunday's storms produced tornadoes but it won't be clear how many there were until the damage assessments are done. 

NEMA officials say trained spotters identified 12 to 15 likely tornadoes on Sunday as the storms moved across the state.