APPENDIX - SIGMET DECODING

Question 1

SIGMET

Code: SIGMET Type

Answer 1

There are three MAIN SIGMET types

• WS
  thunderstorm(TS), tubulence(TURB), icing (ICG), mountain waves (MTW), low-level wind shear (LLWS), dust storm(DS), sand storm (SS), radioactive cloud (RDOACT CLD), Squall line (SQLN

-WV
volcanic ash (VA)

-WC
tropical cyclone

Question 2

SIGMET

Code: Airspace

Answer 2

refers to airspace designation

CN = Canadian airspace

Question 3

SIGMET

Code: FIR

Answer 3

Refers to a FIR identifier (numerical code) eg, winnipeg FIR is 23

Question 4

SIGMET

Code: WMO Heading

Answer 4

All SIGMETs issued in canada have the same WMO heading: CWAO (Canadian meteorological Centre/network operations)

CWAO = Canadian SIGMET

Question 5

SIGMET

Code: DAY/TIME

Answer 5

-first two digits = day of the month
-last four digits indicate time in utc or zulu

Question 6

SIGMET

Code: FIR Designator

Answer 6

Each FIR has a designator that is used for both the FIR and the associated ACC and starts with CZ

CZVR - vancouver
CZEG - edmonton
CZWG - winnipeg
CZYZ - toronto
CZUL - montreal
CZQM - moncton
CZQX - gander

Question 7

SIGMET

Code: Bulletin number

Answer 7

• each SIGMET is issued a bulletin number.
• new SIGMETs supersede the ones before them

eg. SIGMET A4
This SIGMET supercedes A3

Question 8

SIGMET

Code: Validity Period

*dont skip

Answer 8

-SIGMETs include a validity period
-A VALIDITY PERIOD CANNOT EXCEED 4 HOURS
- location indicator of the centre originating or compiling the bulleting is included

example
VALID 162225/170225 CWEG

CWEG is CMAC-W in edmonton.

CANADA HAS TWO ISSUING OFFICES FOR SIGMETs - CMAC-West (CWEG) in edmonton
CMAC-EAST (CWUL) in montreal

Question 9

SIGMET

Code: Location indicator and name of the FIR

Answer 9

This is the flight information region (FIR) name and indicator

Eg. CZWG WINNIPEG FIR

Question 10

SIGMET

Code: Description

*dont skip

Answer 10

This describes the pheomenon using common abbreviations

eg
SQLN TS OBS

A squall line of thunderstorms is observed

Question 11

SIGMET

Code: Location of the phomenon

Answer 11

This describes where the phenomenon is occurring or is forecast to occur. It could be a line, a radius around a point, or an area contained by three or more points on the map

In Canadian SIGMETs, the lat/long as well as a corresponding place name is given for each point

CMAC-east also issues oceanic SIGMETs that only contain lat/long since there are no place names in the middle of the ocean

Question 12

SIGMET

Code: Flight level and extent

Answer 12

SIGMETs may contain only the top altitude of a phenomenon, such as a TS or CB, but may also contain a range of altitudes, such as FL180-240 or SFC-070

Question 13

SIGMET

Code: Movement

Answer 13

This refers to the movement or expected movement of the phenomenon

MOV E 15KT
The squall line of thunderstorms is moving east at 15 knots

Question 14

SIGMET

Code: Change in intensity

Answer 14

This identifies any change in intensity

-NC - NO CHANGE
-INTSFYG: Intensifying
-WKNG: weakening

Question 15

SIGMET

Code: Remarks

Answer 15

This refers to the GFACN areas and/or other FIRs affected

-G: Graphical
-F: Forecast
-A: Area
-CN: Canadian

It is possible to have several SIGMETs covering the same general area