5/2/12 Helpful New Tornado Data?

Scientists from the VORTEX2 group which chases storms to be able to study and understand them better may have uncovered a new key for trying to determine which storms produce tornadoes before they actually formed. This new key piece of evidence is actually linked to something that isn't normally associated with tornadoes.....light rain. Normally supercells, the ones capable of producing tornadoes, are filled with very heavy rainfall and ice. However, as seen in the image below, taken from the VORTEX2 data, there is a ribbon-like area of light rain and small raindrops inside the thunderstorm supercell that spawned the tornado.

This was not originally noticed while the event was happening, but rather, after the fact when scientists were going back over the data. For now, the scientists have decided to call the area a “low reflectivity ribbon,” or LRR, due to the fact that it reflects back much less radar energy than the rainier parts of the storm. This LRR, however, only shows up in specific close-up views that are captured by the more sophisticated radars used in VORTEX2. The earlier field research done in VOTEX1 did not have such sophisticated radar technology.


“We don’t know why it forms or whether it is important in tornado genesis,” said Josh Wurman, head of the research center. “It is probably present in lots of supercells, but, frankly, we won’t know until we look some more. We’re publishing our initial imagery of this newly discovered phenomenon in the hope that scientists will start pondering why it forms and whether it is important.” Wurman says the question is: “Does this affect tornadoes, or is it like a rainbow, scientifically cool but with no effect on the weather?”

At this point, only time will tell. Wurman says no one has come up with a hypothesis to explain the LRR or whether it affects tornado formation just yet.

It is key for these researchers to keep investigating it because a lot of times there are hidden things inside these storms that can tell us things, but you just have to know what to look for, and what it means. Just like hook echoes and debris balls on radar. At first no one knew what they meant, but now meteorologists specifically look for those as tell tale signs of a tornado or funnel cloud.

Sources: Washington Post, NOAA, ABC News