Problem: To be notified when an article has an unusual spike in page views/traffic. This usually indicates there has been an external news story or event driving traffic to Wikipedia, typically signaling the article needs updating with new information/sources.
Short spikes in traffic are normal and are usually short-lived (1 day spires see example graphs) These can be safely ignored as anomalous. However when there is a sustained build-up and trailing off, looking more like a mountain than a spire, there is a probable notable external event driving traffic to the article.
Who would benefit: Anyone keeping an article up to date
Proposed solution: There are three elements. 1) A system for marking which articles to track. Possibly through the watchlist. 2) A system and algorithm for tracking those articles and monitoring for unusual traffic spikes. There might be some custom variables users can set to determine what counts as a traffic spike. 3) Finally a system for notifying users of when a spike occurs. This might be through the watchlist or some other mechanism.