ok I will break it down

Pro for Irops 27jan...mean this flight was the protection for the irregular
operations on the 27jan.

Landing Subj YYT acct snow/low........landing subject to weather conditions in YYT account snow and low ceiling runway and airport conditions.

Air equipment failure could be any kind of ground equipment that is used to
service an airplane although I suspect it may be the airstart unit.

ALTN YHZ....alternate airport is Halifax.

next line is flight diverting to Halifax due to YYT airport conditions.

the last line was probably put in when the flight was in Halifax and it states that the flight was further delayed from it's posted time waiting for weather and runway updates.