In een discussie op het Amerikaanse Storm2K forum is dit de bijdrage van een professioneel meteoroloog:
If you have ever seen a sounding from deep within an intense Tropical Cyclone, you will find that temperatures are very warm high up. Consequently, the ice crystals needed for charge initiation and separation will not be found until way up in the eyewall thus any lightning there is usually high up and weak. To have the amount of CG lightning that was observed in Katrina and Rita requires a tremendous amount of turbulent mixing to bring the charges centers down and hence more than the normal amount of convection typically found in the eyewall. Even more importantly was the lightning in the internal spiral bands of the storms since this is a very rare occurrence as the spiral bands are usually not high enough topped to be T-storms. Bottom line was that these storms were far more convectively active and dynamic than your usual hurricane. In some cases, a RIC might be anticipated if the storm is approach a trough where the flow may result in strong poleward outflow. But in the case of Katrina especially, the outflow was actually strongest to the south even to the point where it suppressed all convection beyond the storm as far as AZ. Another factor with these storms may have been the entrainment of Trade Air which has a different thermodynamic structure than pure mT air and which can release stored up Convective energy quick explosively (as I learned in the Philippines) when something forces it to.
Steve
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