  The ability to predict the long-term impact of a scientific article soon
after its publication is of great value towards accurate assessment of research
performance. In this work we test the hypothesis that good predictions of
long-term citation counts can be obtained through a combination of a
publication's early citations and the impact factor of the hosting journal. The
test is performed on a corpus of 123,128 WoS publications authored by Italian
scientists, using linear regression models. The average accuracy of the
prediction is good for citation time windows above two years, decreases for
lowly-cited publications, and varies across disciplines. As expected, the role
of the impact factor in the combination becomes negligible after only two years
from publication.
