I've noticed that many times when a thunderstorm moves through, I will see the lightning, hear the thunder (upto 15 seconds later -- i.e. lightning was with 3 miles), but nothing shows up on the map. 10-20 miles away there can be strokes plotted.... so there is a sufficient density of stations around me.
I read elsewhere that cloud-cloud strokes are difficult to detect, but is that really the explanation here?
I'd love to be able to watch the map and the expanding sound front and have it be right!
Philip
Much of the lightning we see is cloud to cloud. I have access to USPLN also, and the correlation between them and us for strikes and location is pretty good. They do detect cloud to cloud through some magic secret sauce in their receiver, and there's a lot of strikes that B/O doesn't show that they display as cloud to cloud.
The antenna orientation used for B/O is optimized for cloud to ground strikes: the (almost) vertical lightning channel close to ground radiates such that the variation of the electrical field is up/down, so the vertical E-field antenna picks it up; the magnetic field is radiated such that it varies horizontally, therefore e.g. the ferrite antennas are placed also horizontally. The cloud to cloud strikes have of course a different orientation and they also radiate less and the wave forms are much more varied than for CG strikes. This is in a nutshell the reason why B/O is quite insensitive to cloud-cloud strikes. The commercial lightning location systems are currently trying to improve their detection ability for cloud strikes, since this is a competitive advantage when selling their services.