Reference

The main differences between positive and negative CG (cloud-to-ground) lightning are as follows:

1. Polarity:

   • Positive CG Lightning: Transfers a positive electrical charge to the ground.
   • Negative CG Lightning: Transfers a negative electrical charge to the ground, which is the most common type.

2. Frequency:

   • Positive CG Lightning: Less common, accounting for about 10% of all CG lightning.
   • Negative CG Lightning: Accounts for the majority of CG lightning events.

3. Intensity and Impact:

   • Positive CG Lightning: Often more intense and has higher peak charge, making it more likely to cause fires and damage structures. It is also more lethal to living organisms.
   • Negative CG Lightning: Generally less intense in comparison.

4. Occurrence:

   • Positive CG Lightning: Commonly associated with severe weather conditions, such as supercell thunderstorms, and during the dissipating stage of a storm.
   • Negative CG Lightning: Can occur throughout the life cycle of a storm.

5. Initiation:

   • Positive CG Lightning: An infrequent event that typically occurs in the trailing regions of thunderstorms or out of the anvil cloud.
   • Negative CG Lightning: Initiates from the negatively charged bases of clouds.

Sources:

• NOAA National Severe Storms Laboratory
• NWS JetStream
• Storm Highway

For a visual representation, you can view images like these: