Here's a quick something I rustled up while practicing some coding:
www.dragon-above.com/index.php?p=feature...
Yes, it's a bit silly...but isn't that what a good pulp action encounter is all about? 
If you think any other words/ideas are needed, post them and I'll add them in!
The first one I came upon was something like:
"A falling, illusory ship in Thelanis, which is also in a storm."
:-O
If the ship is illusory, I wouldn't worry about it falling... except the adventurers are apparently on board.
What are your current lists ? It's hard to know what to suggest if we don't know what's in there.
Yeah, sometimes it spits out some things which make little sense. Though you never know, trying to make it make sense could get the juices flowing.
Here's the list. The code picks 2 adjectives ($adj), 1 location ($loc), 1 other location ($loc2), one 'also' event ($also), and two other events for halfway and the end ($half).
$adj[] = "crashing";
$adj[] = "falling";
$adj[] = "burning";
$adj[] = "sinking";
$adj[] = "flying";
$adj[] = "colossal";
$adj[] = "broken";
$adj[] = "illusory";
$adj[] = "crystalline";
$adj[] = "speeding";
$loc[] = "lightning rail coach";
$loc[] = "airship";
$loc[] = "tower";
$loc[] = "bridge";
$loc[] = "storm galleon";
$loc[] = "cliff side";
$loc[] = "back of a warforged titan";
$loc[] = "back of a giant creature";
$loc2[] = "a cave";
$loc2[] = "the Mournland";
$loc2[] = "a dungeon";
$loc2[] = "a citadel";
$loc2[] = "a border fort";
$loc2[] = "a church";
$loc2[] = "a volcano";
$loc2[] = "Khyber";
$loc2[] = "the Elemental Chaos";
$loc2[] = "the Astral Sea";
$loc2[] = "the Feywild";
$loc2[] = "Kythri";
$loc2[] = "Mabar";
$loc2[] = "Syrania";
$loc2[] = "Shavarath";
$loc2[] = "Lammania";
$loc2[] = "Thelanis";
$loc2[] = "Fernia";
$loc2[] = "Risia";
$loc2[] = "Baator";
$loc2[] = "Irian";
$loc2[] = "Dolurrh";
$loc2[] = "Daanvi";
$loc2[] = "Xoriat";
$loc2[] = "SPACE!!!";
$also[] = "on fire";
$also[] = "in a storm";
$also[] = "in a tornado";
$also[] = "underwater";
$also[] = "in a lava flow";
$also[] = "being chased by pirates";
$also[] = "being chased by aberrants";
$also[] = "being chased by an army";
$also[] = "crossing between worlds";
$also[] = "amidst stampeding Tribex";
$half[] = "everything explodes";
$half[] = "a portal to the Abyss opens";
$half[] = "hungry dinosaurs attack";
$half[] = "a fissure opens";
$half[] = "there's an earthquake";
$half[] = "everything collapses";
$half[] = "everybody dies";
$half[] = "reinforcements arrive";
$half[] = "a Siberys dragonshard lands";
$half[] = "lightning strikes";
Ah Trolls, never fail to give me a good laugh, do you?
Ah Trolls, never fail to give me a good laugh, do you?
All in a day's work 
This is absolutely hilarious and fantastic at the same time.
I got such things like a "speeding, crashing lightning rail coach in a dungeon" which is just funny, but I also got this gem:
A speeding, sinking back of a giant creature in Khyber, which is also in a lava flow.
Halfway through the battle a portal to the Abyss opens. At the end, everything collapses.
Imagine playing a PC in that encounter, and having the "everything collapses" be a cliffhanger for next session. That is one HELL of a set-piece.
My only complaint is the "everybody dies" variable. That doesn't make for a good encounter.
adj -> "crumbling"
loc -> "mountain top", "Eldritch machine"
loc2 -> "Everice", "Sharn" (because tower top fights are awesome)
also -> "being chased by dragons", "battling undead", "battling living spells"
half -> "the dead rise", "the Mournland fog rises", "a living dragonmark appears", "Quori mind-seed half the survivors"
I'd change "a Siberys dragonshard lands" to "a hail of Siberys dragonshards falls" 