The most common and most likely answer to this crossword clue is the 9 letter word HAILSTONE
I've seen this crossword clue in The Times
H
A
I
L
S
T
O
N
E
More clues leading to the result HAILSTONE
- Waves down close to front, a certain sign of cold weather
- Hard toenails troubled one in the shower
- Hard toenails have broken hard bit of shower
- Ethanol is drunk, a drop of something hard
- Ethanol is unexpectedly obtained in precipitate?
- This alone surprisingly produces frozen rain
- Bit of bad weather and calls taxi to Nice on vacation
- Welcomes to Tyneside area ball
- One part of a frozen waterfall?
- Salutes quality in a drop of the hard stuff?
Buddy explains!

The straight part
We know that "sign of cold weather" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sign of cold weather = hailstone.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 HAILSTONE mean?
HAILSTONE noun- A single ball of hail, or solid precipitation