Maven not using local repository

You've configured that the SNAPSHOTs should always (<updatePolicy>always</updatePolicy>) be downloaded from your snapshot-nexus. So even if your local cache (the ~/.m2/repository) has a newer version of the snapshot, maven tries to download it from the configured server (http://nexus/content/repositories/snapshots).

Think about changing the updatePolicy for the snapshot-entry. E.g. if you have a CI-server which deploys a SNAPSHOT daily (in the morning) to the snapshot-nexus, change the updatePolicy to daily.