明日(あした) ashita天(てん)気(き) tenkiなら nara外(がい)出(しゅつ) gaishutsuします shimasu。 If the weather's nice tomorrow, I'll go out. Literal Tomorrow weather [if-なら] go-out. 天気なら uses the なら conditional on the noun 天気 — 'if it's fine weather.' なら is the conditional form of the copula だ. Note that 天気 by itself means 'good weather' here, not neutral 'weather.' weatherdaily life~なら (conditional)
明日(あした) ashita天(てん)気(き) tenkiなら nara外(がい)出(しゅつ) gaishutsuします shimasu。 If the weather's nice tomorrow, I'll go out. Literal Tomorrow weather [if-なら] go-out. 天気なら uses the なら conditional on the noun 天気 — 'if it's fine weather.' なら is the conditional form of the copula だ. Note that 天気 by itself means 'good weather' here, not neutral 'weather.' weatherdaily life~なら (conditional)