Isa is the vowel sound “ee”
Anglo-Saxon rune poem (from ragweedforge.com)
Ice is very cold and immeasurably slippery;
it glistens as clear as glass and most like to gems;it is a floor wrought by the frost, fair to look upon
Isa is the rune of ice and cold. In a very literal way, today was a very cold day in Southern California. Not record lows, but according to weather history for the area, very close to it.
Spiritually, it shows that things have been put on ice. Generally it indicates things are frozen and locked up, unable to move or break free, contained or trapped by things around them. Of course, when things are frozen over, it might be an opportunity to pass them by, as you able to slide past easily (and hopefully gracefully) seeing things locked away, perhaps what was once ugly, not glistens like a jewel, frozen away