Since, by definition, TEMPO conditions will prevail for less than half the time the 'most likely' conditions are the permanent (BECMG) conditions.

 

BECMG 2123 changes the lowest cloud base to 3 to 4 oktas at 1,500ft by 2300hrs.   The TEMPO 2306 indicates that the cloud base could, temporarily come down to 800ft but the permanent conditions are more likely.