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Significant Weather Information (SIGMET)

The Hong Kong Observatory's Airport Meteorological Office is responsible for issuing SIGMET on hazardous weather and phenomena in the atmosphere that may affect the safety of aircraft operations within a designated airspace over the northern part of the South China Sea (see map below).


Hazardous weather and phenomena in the atmosphere include:

  • thunderstorms
  • tropical cyclones
  • turbulence
  • icing
  • mountain wave
  • duststorm
  • sandstorm
  • volcanic ash
  • radioactive cloud

Some abbreviations used in SIGMET:

Abbreviations Meaning
TS  thunderstorm
TC tropical cyclone
VA volcanic ash
TURB turbulence
ICE icing
MTW mountain wave
GR hail
DS duststorm
SS sandstorm
CB cumulonimbus
OBSC obscured
EMBD embedded
FRQ frequent
SQL squally
HVY heavy
SEV severe
INTSF intensify
NC  no change
WKN weaken
MOV move
RDOACT CLD radioactive cloud