Global SIGMET map

SIGMETs (Significant Meteorological Information) are issued by WAFC/MWO centres describing phenomena significant to flight safety. AvioWeather collects them from the 27 global FIRs and draws them as coloured hazard polygons.

Hazard colours

TS / CB / CONVECTIVE

Red — thunderstorms, cumulonimbus

TURB

Orange — moderate or severe turbulence

ICE / ICING

Dark blue — airframe icing

MTW

Brown — mountain wave

MTN OBSCN

Grey — mountains obscured by clouds

VA

Purple — volcanic ash

TC

Dark red — tropical cyclone

GR

Cyan — hail

DS / SS

Sand brown — dust/sandstorm

RDOACT

Yellow — radioactive cloud

View modes

• Map (default): Leaflet with OpenStreetMap, zoom 2–9, popup on click
• List: editorial table grouped by hazard with raw text, FIR and validity
• Top chips filter by hazard: click to isolate one, click again to reset to All

Geometry

The backend pre-splits polygons that cross the antimeridian (±180° longitude) into multiple rings so you never see a line slicing the map. Open SIGMETs like AIRMET LINE FROM render as dashed polylines.