SOHO/MDI magnetograms combined with the Potential-Field Source-Surface (PFSS) model can be used to generate a model of magnetic field lines in the lower part of the solar corona. When these models are compared to the loops visible in TRACE imagery, a bad match (as in this case) indicates that the region will generate flare events over the next few days.
This movie zooms in to the solar surface then fades to a time varying magnetogram. The PFSS model is overlaid on the source magnetic field, then compared to the TRACE loops. Following the region for several days, we see a major flare event.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 126.96.36.199.0