| (1) | A MWO established in terms of regulation 174.02.02(2) shall prepare and issue SIGMET information for specified hazardous en-route weather including volcanic ash and tropical cyclones within its area of responsibility. |
| (a) | base volcanic ash cloud and tropical cyclone SIGMET on advisory information received from VAACs and TCACS; |
| (B) | keep a period of validity of a SIGMET message for normal weather phenomenon too a maximum of four hours; |
| (c) | issue SIGMET for normal weather phenomenon not more than four (4) hours before commencement of a period of validity; |
| (d) | cancel a SIGMET when a phenomenon is no longer occurring or expected to occur; |
| (e) | issue SIGMET for volcanic ash and tropical cyclone as soon as practicable but not more than 12 hours before a commencement of a period of validity; |
| (f) | update SIGMET for volcanic ash and tropical cyclone every 6 hours; |
| (g) | ensure that the period of validity of volcanic ash cloud and tropical cyclone SIGMET is recorded for up to six (6) hours; and |
| (h) | request that information about volcanic ash be published in a NOTAM. |
| (3) | A MWO shall maintain close coordination with associated area control centre or flight information centre to ensure consistency of information published in a SIGMET and a NOTAM. |
[Regulation 174.04.7(3) substituted by regulation 8(m) of Notice No. 5008, GG50880, dated 28 June 2024 (Twenty-Ninth Amendment of the Civil Aviation Regulations, 2024)]
[Regulation 174.04.7 inserted by regulation 19 of Notice No. R. 520, GG 42632, dated 29 March 2019 (Twentieth Amendment of the Civil Aviation Regulations, 2019)]
