×
Welcome to the CPL Meteorology question and answer forum. Please feel free to post your questions but more importantly also suggest answers for your forum colleagues. Bob himself or one of the other tutors will get to your question as soon as we can.
NOSIG meaning
bjmolony
Topic Author
bjmolony created the topic: NOSIG meaning
Hi All
Been doing the bob tait online prac exam number 1 for MET. question 33 - the term NOSIG indicates:
A. the weather described in the METAR is expected to remain unchanged for the next three hours.
B. no significant weather is expected during the validity period of the taf.
The correct answer per the online exam is A.
However in the AIP GEN 3.5 pg 40 "NOSIG" is used to indicate that no significant changes to the elements in wind, visibility, weather or cloud, as reported in the METAR/SPECI, are expected to occur during the validity period of the TTF.
This is attached to the METAR/SPECI at some aerodromes (e.g. Sydney and Canberra) and will be denoted either with TTF METAR or TTF SPECI.
The TTF is valid for 3 hours from the time of observation of the METAR, and will supercede the TAF during the 3 hour period as it is considered a more accurate forecast. This is relevant if you expect to arrive during the validity of the TTF. If arriving outside of the TTF period, then use the TAF.
When NOSIG is attached to a TTF, it means what is reported in the METAR is expected to remain unchanged for the next 3 hours.
If there are changes expected within the 3 hour period the TTF METAR/SPECI report will be followed by FM or BECMG conditions below it.
