Only with reading ナウ
Describes something fashionable or current. Often used in a slightly retro or playful way, reminiscent of 1980s–90s slang.
from English
currently at ...; now doing ...; in the middle of ...
Internet slang suffix attached to a place or activity to indicate one's current status, especially in social media updates. Usually written in hiragana.
At a café right now.
In Shibuya right now.
That outfit is a bit trendy, isn't it.
Let's check out the latest info.
勉強なう。
Studying now.
これはナウなファッションだ。
This is trendy fashion.
Working right now.
古い means old-fashioned or outdated, the opposite of ナウ's sense of being current and trendy.
ナウキャスト is a specialized meteorological term for short-term weather forecasting, not related to ナウ's meaning of 'trendy' or 'currently doing'.
nowcast; very short-term forecast
From English 'now'. The trendy sense emerged in Japanese slang around the 1980s; the internet slang suffix developed later from the same English word.