Cut-off low

A cut-off low (or cutoff low), sometimes referred to as the weatherman's woe, is defined by the National Weather Service as "a closed upper-level low which has become completely displaced (cut off) from basic westerly current, and moves independently of that current." Cut-off lows form in mid-latitudes (usually in the subtropics or between 20° and 45°) and can remain nearly stationary for days.