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HOME > Monitoring and Data > Monitoring Weather & Climate > Blocking > Northern Hemisphere Blocking Climatology

Using the blocking index of Tibaldi and Molteni (1990) we can consider the frequency of "blocked days" for each of the four traditional seasons (DJF, MAM, JJA, SON) for the northern hemisphere for the period 1950 to 2000. The results come from the NCEP/NCAR reanalysis.

Frequency of blocked days for each of the four traditional seasons

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