© 2017 IEEE. We propose to use the temporal coherence of a time series to extract using Vertex Component Analysis (VCA) the suitable set of endmembers for each scene. The reconstruction error computed on the two previous scenes for each date is used to constrain the selection of the set of endmembers produced by VCA. Snow cover estimation is considered as application. We tested different approaches for abundance estimation (FCLSU, SUnSAL, ELMM) over the French Alps from Moderate Resolution Imaging Spectroradiometer (MODIS) images. Results shows a decrease of the false positive rate with the proposed approach.