From NASA:
Image mosaic of Arctic storm. (Credit: NASA/Goddard/MODIS Rapid Response Team) An unusually strong storm formed off the coast of Alaska on August 5 and tracked into the center of the Arctic Ocean, where it slowly dissipated over the next several days.HT: The Canadian Broadcasting Corporation
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this natural-color mosaic image on Aug. 6, 2012. The center of the storm at that date was located in the middle of the Arctic Ocean.
The storm had an unusually low central pressure area. Paul A. Newman, chief scientist for Atmospheric Sciences at NASA's Goddard Space Flight Center in Greenbelt, Md., estimates that there have only been about eight storms of similar strength during the month of August in the last 34 years of satellite records. “It’s an uncommon event, especially because it’s occurring in the summer. Polar lows are more usual in the winter,” Newman said....MORE
