On the nature of things (books 4 - 6)   

And the keen onset of the wind have weakened
That crust, lo, then the cloud, to-split in twain,
Gives forth a hideous crash with bang and boom.
No marvel this; since oft a bladder small,
Filled up with air, will, when of sudden burst,
Give forth a like large sound.
There's reason, too,
Why clouds make sounds, as through them blow the winds:
We see, borne down the sky, oft shapes of clouds
Rough-edged or branched many forky ways;
And 'tis the same, as when the sudden flaws
Of northwest wind through the dense forest blow,
Making the leaves to sough and limbs to crash.
It happens too at times that roused force
Of the fierce hurricane to-rends the cloud,
Breaking right through it by a front assault;
For what a blast of wind may do up there
Is manifest from facts when here on earth
A blast more gentle yet uptwists tall trees
And sucks them madly from their deepest roots.
Besides, among the clouds are waves, and these
Give, as they roughly break, a rumbling roar;
As when along deep streams or the great sea
Breaks the loud surf. It happens, too, whenever
Out from one cloud into another falls
The fiery energy of thunderbolt,
That straightaway the cloud, if full of wet,
Extinguishes the fire with mighty noise;
As iron, white from the hot furnaces,
Sizzles, when speedily we've plunged its glow
Down the cold water. Further, if a cloud
More dry receive the fire, 'twill suddenly
Kindle to flame and burn with monstrous sound,
As if a flame with whirl of winds should range
Along the laurel-tressed mountains far,
Upburning with its vast assault those trees;
Nor is there aught that in the crackling flame
Consumes with sound more terrible to man
Than Delphic laurel of Apollo lord.
Oft, too, the multitudinous crash of ice
And down-pour of swift hail gives forth a sound
Among the mighty clouds on high; for when
The wind hath packed them close, each mountain mass
Of rain-cloud, there congealed utterly
And mixed with hail-stones, breaks and booms...

Likewise, it lightens, when the clouds have struck,
By their collision, forth the seeds of fire:
As if a stone should smite a stone or steel,
For light then too leaps forth and fire then scatters
The shining sparks. But with our ears we get
The thunder after eyes behold the flash,
Because forever things arrive the ears
More tardily than the eyes- as thou mayst see
From this example too: when markest thou
Some man far yonder felling a great tree
With double-edged ax, it comes to pass
Thine eye beholds the swinging stroke before
The blow gives forth a sound athrough thine ears:
Thus also we behold the flashing ere
We hear the thunder, which discharged is
At same time with the fire and by same cause,
Born of the same collision.
In following wise