BT Ber 59a(51) :ובצפרא אתי איסתנא חריפתא וגלו לשמיא‏ : the north wind comes in the morning and exposes the sky [i.e. blows away the clouds]
See the entire entry for gly vb. to uncover; D to exile

BT Ber 59a(51) :איסתנא חריפתא‏ : a fierce north wind
See the entire entry for ḥarrīp̄ adj. sharp