The ‘Albuquerque Box’ explained

ALBUQUERQUE, N.M. (KRQE) – During the night time hours, cool air over the northern mountains sinks down to the valley floor. The heavy cool air then makes its way south to the lowest point which in this case happens to be the Rio Grande Valley.
So as day breaks the northerly cool air flow sets the stage for part of the “Box”.
When the “Box” is in full force as balloons take off from Balloon Fiesta Park the balloons move south being pushed by the northerly winds from