ARES folks are you familiar for the local criteria and the difference between a weather warning and an advisory ? This may be of assistance
| ALERT TYPE | LOCATION | THRESHOLD CRITERIA |
|---|---|---|
| Advisory | National, except Nunavik* | A generic weather advisory. One example might be on days when funnel clouds are expected, but a Tornado alert would not be appropriate. |
| Warning | National, except Nunavik* | A generic weather warning may be issued for extreme weather events for which there is no suitable warning type, because they rarely occur.
A generic weather warning may also be issued for other weather events during situations where the environment is vulnerable due to pre-existing conditions and any further weather could result in a significant hazard. For example: 50 km/h winds following an ice storm which could cause structural wind damage. A generic weather warning may also be issued for situations where the event is not expected to reach warning criteria values, but there is a special reason for the warning. For example: the first event of the season, or an off-season event. |
http://www.ec.gc.ca/meteo-weather/default.asp?lang=En&n=D9553AB5-1#winterStorm