An EFAS Informal notification is issued when at least a 40 % total probability of exceeding critical flood thresholds is forecasted in a river basin for which an EFAS partner exists, but the forecasted event does not satisfy the rules of an EFAS Formal Flood Notification, e.g. regarding warning lead time or size of the river basin (less than 1000 km2, but greater than 500 km2).
Be aware that the skill of informal notifications is not necessarily less than formal ones, especially if they are informal notifications due to their short lead time. In that case, the skill can actually be higher.
The format of an EFAS Informal Flood Notification is similar to the one for Formal Flood Notifications. The only additional information is a comment explaining the reason(s) why it is an Informal Notification.
EFAS Formal Notification e-mail