A Heavy Rain sub-event causing lightning to thrash the sky.
It would be hard to say more about this sub event. Heavy Rain work the same way during a thunderstorm, as long as a few other events who may add up to the current one or occur a bit after; Dense Fog, Snowfall.
Lightning works a bit differently than it does in the Overworld. Sparks will begin to form, (usually on the ground) where lightning will strike. The number and speed of the sparks increase over the course of about 10 seconds, before a lightning bolt connects with the sparks.
Lightning will also frequently strike around a Draedon flying in a thunderstorm, so be wary.
Experiment it by yourself! Resuming this event to any decent picture may be hard to find as usually lightning won't last more than one second and the sky become quite dark; even when equip with a night vision effect.
Lightning reflection on the landscape
|The Betweenlands Environment|
|Dimensions||The Betweenlands • The Nether • The Overworld|
|Biomes||Coarse Islands • Deep Waters • Marsh • Patchy Islands • Sludge Plains • Swamplands|
|Natural||Cavern (Lake) • Cragrock Spire • Giant Bulb-Capped Mushroom • Giant Hollow Log • Giant Root • Hearthgrove Tree • Nibbletwig Tree • Rubber Tree • Sap Tree • Silt Beach • Spirit Tree • Underground Oasis • Weedwood Tree (Giant • Rotten)|
|Buildings||Cragrock Tower • Druid Circle • Idol Head Statue • Ruins (Underground) • Shrine • Sludgeon • Tar Pool Dungeon • Wight Fortress|
|Events||Auroras • Blood Sky • Dense Fog • Heavy Rain • Rift • Snowfall • Spook • Thunderstorm • Winter|
|Mechanics||Aspects • Corrosion • Decay • Food Sickness • Middle Gem Circle • Radial Equipment Menu|
|Other||Advancements • Loot Tables • Music|