"2aeb8e10-b7f8-429e-b9f6-968ece330741" . "BLOCKING INDEX"^^ . "Blocking in the southern hemisphere typically occurs at lower\nlatitudes when compared with the northern hemisphere. The index\nfollows Tibaldi et al. (1994).\nThe European blocking index is based on observations of pentad (5-day\naverage) wind over the region 15W to 25E and 35n to 55N. If the pentad\nzonal wind equals the climatological value for that time period, the\nindex is zero. If the pentad zonal wind is less than average the index\nis postive, while the opposite is true if the index is\nnegative. Values close to +/- 1 indicate relatively strong events."^^ . .