L. Eye Character is the brief description of what conditions of the eye are on radar from the flight meteorologist. CLOSED WALL means that the ring of thunderstorms that composes the eye are entirely intact with no breaks in them. If there are gaps or breaks they would be indicated by something like OPEN NE if they are missing to the NE. If at least 50% of the eye is NOT covered by storms it will get reported as NA. In this case the eye was entirely intact as shown by the CLOSED WALL report.