I turned on the Greenville/Spartanburg, SC NWS radar and flipped it into velocity mode. This gives you a picture of what we will be using when we have tornado warnings. First thing to do is locate where the radar site is. I labelled that with a white dot. Any green color shaded is wind moving TOWARD the radar site. Any red color displayed is wind moving AWAY from the radar site. Now look where the brighter reds and greens (higher speeds) are in close proximity to one another. Knowing that most tornadoes and funnels spin counterclockwise, we then look where these “couplets” form rotation. It’s easy now to see where the possible tornadoes are. I labelled them with white circles. Now just because there are greens and red couplets together doesn’t exactly mean there will be a tornado. Where it says “New warning here?” there appears to be some intense rotation. However you can’t just look at the velocity on doppler. I switched it over to “reflectivity mode” which shows us where the intense precip is…and there’s no storm there.
So, even though picking out rotating storms is a little difficult at first, the combo of experience and 13Futuretrack makes it possible to see where a tornadoes will form BEFORE they touch down. -ES
This post was written by Eric Sorensen on April 10, 2009