Authors: Nishu Karna(CfA), Tatiana Niembro(CfA)

Coronal holes are the source of the fast solar wind, and thus play a crucial role in heliophysics as one of the main drivers of geomagnetic activity. It is widely recognized that the presence of large open-field coronal structures (coronal holes) near close-field structures (active regions) can increase the free energy content of the underlying magnetic system and bring it closer to an instability threshold often resulting in geomagnetic storms. In this study, we present a comprehensive observational and modeling of a geo-effective event with Dst index -80 nT observed on 2011 May 28 when a coronal hole was bordering an active region. We produce 3D magnetic field configurations that are consistent with the observations and employ numerical models to track the CME/ICME propagation up to 1 AU.