Abstract
The average strength of the Siberian Anticyclone is defined. Daily values of average strength of this anticyclone have been computed for each day for the period of 1st November 1967 to 30th April 1968 from the daily 12 GMT, NHAC (New Delhi) charts. A power spectra of this data has been computed. A significant 5 day periodicity is observed. A possible connection of this anticyclone and western disturbances is discussed.