The Tornado That Almost Went Unseen - 09/13/13

When I came into work this afternoon, I opened up the chat room we have with the National Weather Service like always. What I saw immediately surprised me.




I was in front of the radar when it happened last night (Thursday, Sept. 12) around 8p. How did I miss it? There was never a Tornado Warning issued. How did the NWS miss it? Here are two reasons why:


1)     Claysville, where the tornado touched down, is approximately 85 miles from the closest radar site in Pittsburgh (as seen on the image). By the time the radar beam makes it there, it is already almost 9,000 ft above the ground. Since the rotation was so weak in this case, it was never detected by the radar at that elevation. [Also to note, all tornadoes are too small to be picked up by radar. It's the larger scale (called mesoscale) rotation that is detected.] Even the other nearby radars in Cleveland and Charleston had the same issue since Claysville is situated right in between all of the radars.

2)     This tornado (and all associated rotation) was very short lived lasting under one minute. The amount of time it takes for the radar beam to make a complete sweep is about six minutes. Coincidentally, but not surprisingly when you think about it, it happened in between sweeps of the beam.

If it weren't for the video (seen here) captured and sent in to the NWS by the Guernsey County deputy, the tornado likely would have never been documented. This goes to show you, while radars are sophisticated and  incredibly important, there is still some room to improve. Fortunately, the damage was limited and nobody was injured.