ISS027-E-6500 Click the photo number to access all resolutions available and the database record.
In these astronaut photographs (also see ISS027-E-6501) from the cupola—taken one minute and thirteen seconds apart on March 20, 2011—two distinct cyclonic vortices whirl within an area of low pressure that spanned the Pacific coast from southern California to Vancouver Island. Part of one of the ISS solar arrays also is visible at image upper left in both images.
The vortices indicate the positions of two storm systems located within a broad area of low pressure over the northeastern Pacific Ocean. Through a process known as cyclogenesis, rotating cyclonic weather systems develop, mature, and dissipate along the frontal zones between different air masses (sometimes termed a zone of occlusion). The smaller of the two systems (ISS027-E-6501) displays a dense cloud pattern and arcing band of the cold front extending from the center of a young, maturing cyclone. The diffuse cloud pattern of the larger system (ISS027-E-6500) indicates an older, dissipating system.
