Table 3 Comparison of present and proposed VAFFs
From: Improvements of volcanic ash fall forecasts issued by the Japan Meteorological Agency
Present VAFF | Proposed VAFF | |||
|---|---|---|---|---|
Type and timing of forecast | Volcanic Ash Fall Forecast | Regular Information | Preliminary Forecast | Full Forecast |
Issued within 30–40 min of onset of eruption | Issued regularly (e.g. 3 hourly) before possible eruption | Issued within 5–10 min of onset of eruption | Issued within 20–30 min of onset of eruption | |
Contents | Forecast1 of situation at six 1-h intervals after onset of eruption: Ash fall area. Prefectures where ash may fall | Forecast1 for an assumed eruption: Ash-fall area. Lapilli-fall area. Recommended actions for affected communities | Forecast2 for first hour after onset of eruption: Ash-fall area and quantity. Municipalities affected. Lapilli-fall area. Recommended actions for affected communities | Forecast2 of situation at six 1-h intervals after onset of eruption: Ash-fall area and quantity. Municipalities affected. Start of ash fall for each municipality. Recommended action for affected communities |