The TAF had been described as the weather foreseen on the airfield for 9 hours. Every 3 hours, a new TAF comes to replace the old.

For example: LFMH 0615 VRB05 6000 8ST006 PROB 30 TEMPO 0608 2000 10BR 8ST003 GRADU 0912 18012 9999 8SC020 TEMPO 1215 60RA 8SC013 =