A method includes, in a memory including analog memory cells, storing first data in a group of the memory cells using a first type of storage command that writes respective analog values to the memory cells in the group. Second data is stored in the memory cells in the group, in addition to the first data, using a second type of storage command that modifies the respective analog values of the memory cells in the group. Upon detecting imminent interruption of electrical power to the memory during storage of the second data, a switch is made to perform an alternative storage operation that is faster than the second type of storage command and protects at least the first data from the interruption.