Beautiful weather for the first time in a while, isn't it.
Literal
For-a-while-first [gen-の] good weather [copula-だ] [confirm-ね].
しばらくぶり '(for the) first time in a while' is a set adverbial noun (しばらく 'a while' + ぶり 'interval / after a gap'), used for things resumed after an absence — 'for the first time in a long while.' A simple small-talk opener about the weather. Classic casual sentence-final ね inviting the listener's agreement.