The most common and most likely answer to this crossword clue is the 8 letter word WINDSOCK
I've seen this crossword clue in The Daily Telegraph
W
I
N
D
S
O
C
K
Buddy explains!
The straight part
We know that "shower of blows?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case shower of blows? = windsock.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does WINDSOCK mean?
WINDSOCK noun- A large, conical, open-ended tube designed to indicate wind direction and relative wind speed, used especially at smaller airfields.