Everlasting:

[Philatone]

hey billy!

Black heralded in the storm--...a think a noun would make a stronger subject than the adjective "Black"
Low minacious clouds argued...comma maybe at the end?
thumping chests and roaring.
Throaty obscenities flew
within cumulonimbus....starts to feel a bit repetitive with the images; i already have a sense of anger and aggression from the "thumping" and "roaring". maybe "within" could be trimmed to "in"?
just two seconds after blue...missing cap. J; that being said, the "just" really isn't needed

Kids swam streets, oblivious..."oblivious" doesn't work for me; it's hard to show obliviousness, but being blatantly told about it doesn't make things better.
power lines lay limp. Unlit...considered chopping the "limp" and making the period a comma
tipper trucks ploughed the water,
loaded to the gunnel's, high
enough for human debris
to be carried from their roofs...i wanted a stronger word than "carried"

Once, it cleared and lightness sprang...."lightness" doesn't sit well with me, personally
floods grew weak and settled down,...could you find a way to change "weak" into something that plays with "settled down"--something that conveys moving, finally finding a new home, or an idea like that?
people cheered, defences down.
All too soon the laughter died:
Anger raced across the sky
then dropped like rods of iron.....making this a metaphor instead of a simile would give you added strength, e.g., "before dropping *adjective* iron

Again it rained.

just a couple of things to ponder. i like the scene you capture