Cyclone Tracks - Extratropical N. Hemisphere

Cyclone Tracks - Extratropical N. Hemisphere is a historical digital data set archived at the National Climatic Data Center (NCDC). The major data variables and parameters are twelve hour positions with direction and speed of movements. The extratropical cyclone movements were digitized from NMC 6-hourly northern hemisphere cyclone position maps. However, the file only contains the 12-hourly positions. A related file is 9629 (C00290) which was prepared for all pressure centers (cyclones and anti cyclones) from the Northern Hemisphere historical map series for the period January 1899 through June 1939.