、。
She got caught in a sudden afternoon shower and was drenched.
Literal
[topic-は] afternoon-shower [in-に] encountered, drenched [into-に] became.
夕立 (ゆうだち) is a specifically Japanese weather term: a sudden, heavy late-afternoon shower characteristic of the hot, humid summer months. They're often dramatic but brief, sweeping in with thunder and ending as abruptly as they started — a defining feature of Japanese summer. に遭う ('to encounter, run into') is typically used for unfortunate or unwanted experiences (事故に遭う 'have an accident,' 雨に遭う 'get caught in the rain'). 遭い is the連用形 (continuative form) used here as a clause-linker, slightly more literary than 遭って. ずぶ濡れ is an emphatic form of 濡れる ('get wet') with the intensifier ずぶ — meaning 'soaked through, drenched.'