The information as defined in ICAO Annex 3 Amdt 82 and PANS-MET:
- expected dimensions (horizontal and vertical) of significant volcanic ash cloud at four concentration thresholds (0.2mg/m3, 2mg/m3, 5mg/m3 and 10mg/m3)
- gridded deterministic forecast of significant volcanic ash cloud showing the expected ash concentration
- gridded probabilistic forecast of significant volcanic ash cloud showing the probability of exceeding four concentration thresholds (0.2mg/m3, 2mg/m3, 5mg/m3 and 10mg/m3)
Note: significant in this context means an ash cloud that poses a widespread impact to aircraft operations and air navigation.