Weird Flow using Lists and Jenkins pipeline parallel

[Isaac Aymerich]

this work as I expect

stage("paralelo"){

       def paralelo=[:]

       for(def counter=1;counter<6;counter++){

           def value=counter

           paralelo["branch${counter}"] = {

               print "hello ${value}"

               if(value==5){

                   error 'died'

               }

           }

       }

        catchError{

           parallel paralelo

       }

   }

but if we move

def value=counter

inside

 paralelo["branch${counter}"] = {

all the parallel executions get the same value in $counter variable (last value)

anybody could explain me what exactly is happening?

Thank you