Welcome shower (4)
I believe the answer is:
hail
I believe this clue is a double definition.
'welcome' is the first definition.
(I've seen this before)
'shower' is the second definition.
(I have seen 'Cold shower' mean 'hail' so perhaps 'shower' could also mean 'hail')
(Other definitions for hail that I've seen before include "Welcome - precipitation" , "cold weather" , "Weather - greeting" , "Ice pellets - greeting" , "weather forecast?" .)