Additional TAF Amendment Criteria
Weather
| If the TAF forecast | Amend if |
| Thunderstorms, freezing precipitation or ice pellets | Phenomenon is no longer expected to continue |
| No thunderstorms, freezing precipitation or ice pellets | Occurs (and expected to continue) or the phenomenon is expected |
Wind Direction, Speed and Gusts
| TAF | Amend if these occur (and expected to persist) or are expected |
| Direction | Mean wind direction will differ by 30 degrees or more with mean wind speeds of 12 knots or higher |
| Speed (if 12 knots or higher) | Mean wind speed differs by 10 knots or more |
| Calm or light and variable winds forecast | Mean wind speeds are expected to become 12 knots or higher |
| Gusts | Gusts > 10 knots above forecast gust (See Note below) |
| No gusts forecast | Gusts > 10 knots above mean forecast speed (See Note below) |
Forecast mean refers to average wind direction or speed expected over the specified forecast group time period.
Note: Criteria applies when mean wind speeds are observed or expected to be 12 knots or greater.
Non-Convective Low Level Wind Shear (LLWS)
| TAF | Amend if these occur (and expected to continue) or are expected to occur |
| LLWS | LLWS no longer expected |
| No LLWS | LLWS |