Lee ebe a n'okpuru ma zaa ajụjụ ahụ n'otu asụsụ ahụ dị ka ebe a: Ebe a: Ọkachamara n'ihe banyere oké ifufe bụ William M. Gray na ndị otu ya na Colorado State University na-ewepụta amụma nke oké ifufe na-eme kwa afọ, iche na National Oceanic and Atmospheric Administration (NOAA). Ndị otu Gray chọpụtara na ọnụ ọgụgụ nke oké ifufe kwa oge n'etiti 1950 na 2000 bụ 9.6 oké ifufe na-ekpo ọkụ, 5.9 oké ifufe, na 2.3 oké ifufe (oké ifufe karịrị Nkebi nke 3).
Mahadum Steeti Colorado