Journal level metrics don't tell the whole story about the impact of a particular article. Article level metrics are far more meaningful in highlighting the impact of an individual paper. A good introduction to the topic can be found on the SPARC (the Scholarly Publishing and Academic Resources Coalition) website.
Example: Article Metrics in Scopus
The number of citations that an article has garnered has long been recognized as a measure of its impact. Usually the citations are an example of scientists building positively on previous work, but an article may also be cited for other reasons, including the fact that it is an example of poor research. (See the Retraction Watch list of the 10 most highly cited retracted papers). Citation counts can be seen in several databases including PubMed, Scopus, ResearchGate, and Google Scholar. However, the numbers vary from database to database because they are based on the number of citations found in the papers in that database and no one database is all-inclusive.
Example: Citation counts in Google Scholar
Example: PlumX altmetrics in Science Direct
Example: Altmetrics in Dimensions retrieved from Altmetric icon under article citation:
The Field-Weighted Citation Impact can be used to measure either article impact or author impact. It was developed by Elsevier and is used in Scopus SciVal. Similar to the RCR, it compares the number of citations an article received to the number of citations that articles in that discipline receive on average.
Example: Highly cited article in Scopus