i have 2 questions: 1. is there a revised fujita scale that uses ef1, etc. and if so, how it it different from the old one that uses just f1, etc.? 2. what are the paths that lightning can take - ground to sky, sky to ground, etc?

MIKE MOSS SAYS:      Annette,    You are correct that the "Enhanced Fujita Scale" is now in place and has superseded the original Fujita scale, so that all new tornadoes are currently rated as, for example, EF1 or EF4, etc. Rather than repeat all the reasoning ad background here (essentially, years of research and study have led to better methods for relating observed damage patterns to potential wind speeds and have lowered the estimates of winds required to accomplish the more severe damage seen in higher-rated tornadoes), I'll refer you to an overview document posted at the Storm Prediction Center Web site. See

http://www.spc.noaa.gov/efscale/

As for your second question, lightning is a versatile phenomenon, and there are cloud to ground, ground to cloud, cloud to cloud, and intracloud strikes, and each of those can be positive or negative discharges, meaning that lighting can travel amongst almost every reasonable combination of initiation and termination point you might think of.