EUR SIGMET GUIDE
3.2.1 Although Annex 3 provides one general SIGMET format, which encompasses all weather
phenomena, it is convenient when describing the structure and format of the messages to distinguish between
three types of SIGMET, as follows:
- SIGMET for en-route weather phenomena other than volcanic ash or tropical cyclones
(this includes: TS, TURB, ICE, MTW, DS and SS); this SIGMET will be referred as
WS SIGMET;
- SIGMET for volcanic ash (VA SIGMET) (to be referred also as WV SIGMET)
- SIGMET for tropical cyclones (TC SIGMET), not described in this doc
3.4.2.3 The following has to be considered when determining the validity period:
- the period of validity of WS SIGMET should not exceed 4 hours;
- the period of validity of VA SIGMET should be up to 6 hours;
for VA SIGMETs the lead time may be up to 12 hours
3.4.2.4 The period of validity is the period during which the SIGMET is valid for transmission to
aircraft in flight.
Examples:
1. SIGMET for an observed phenomenon:
WSIE31 EIDB 241120
EIDB SIGMET 3 VALID 241120/241500 EINN-
2. SIGMET for a forecast phenomenon (expected time of occurrence 1530)
WSSG31 WSSC 251130
WSSA SIGMET 1 VALID 251530/251930 WSSM-