  Using time- and angle-resolved photoemission spectroscopy, we examine the
unoccupied electronic structure and electron dynamics of the type-I Weyl
semimetal PtBi$_2$. Using the ability to change the probe photon energy over a
wide range, we identify the predicted Weyl points in the unoccupied
three-dimensional band structure and we discuss the effect of $k_\perp$
broadening in the normally unoccupied states. We characterise the electron
dynamics close to the Weyl point and in other parts of three-dimensional
Brillouin zone using $k$-means, an unsupervised machine learning technique.
This reveals distinct differences -- in particular, dynamics that are faster in
the parts of the Brillouin zone that host most of the bulk Fermi surface than
in parts close to the Weyl points.
