Positive lightning is a rare, highly powerful type of cloud-to-ground strike that originates in the positively charged upper regions of a thunderstorm.
Key Characteristics
Rarity: Makes up less than 5% to 10% of all lightning strikes.
Power: Can pack up to 300,000 amps and 1 billion volts (roughly ten times stronger than standard negative lightning).
Duration: Lasts significantly longer and generates much louder, house-shaking thunder.
Appearance: Often appears as a single, massive, and vibrant bolt rather than a heavily branched web.
Why It Is Dangerous
The "Bolt from the Blue": Because it originates high up in the storm's anvil, it can travel sideways and strike the ground up to 10 to 20 miles away from the rain or even under clear blue skies where a storm appears to have passed.
Destruction: It is responsible for a large percentage of severe power line damage and devastating forest fires because the intense electrical current flows for a longer duration.
Negative lightning is a cloud-to-ground strike that transfers a negative electrical charge from the base of a storm cloud to the Earth.
How It Works
Charge Buildup: Ice crystals and graupel (small hail) collide inside a storm cloud, separating charges so the cloud base becomes negative and the ground below gains a positive charge.
Stepped Leader: A channel of negative charge called a stepped leader moves downward from the cloud in quick steps.
Return Stroke: Positive charge rises from the ground (upward streamers) to meet it, creating the bright electrical discharge we see as lightning.
Key Characteristics
Frequency: Makes up about 90% to 95% of all cloud-to-ground lightning strikes.
Location: Usually strikes directly beneath the thunderstorm, often inside the heavy rain shaft.
Power: Typically carries around 30,000 amps of electrical current (less powerful than positive lightning, which can exceed 100,000 amps).