What does the quote 'less deadly than the air the shudders black with snow" mean?
Owen contrasts the battle with weather, that the weather is the most deadly opponent. And that the battle itself is less detrimental than the weather.
colour imagery of the adjective "black" connotes to finality emphasises the mortal peril of the soldiers.
The unbearable weakness of the cold makes the unbearable weakness of the war to shine.