More on the Snowicane

In the Comments section after the “Congratulations, AccuWeather” you will find a comment from one of our readers that raises a valid question comparing Snowicane (a term I supported coining) with a term, “Tornado Emergency,” that I do not support.  I would like to elaborate on this and I could not do it justice as a brief comment, so I am making it a separate posting.

As the tornado headed for the southern part of the Oklahoma City Metro Area on May 3, 1999, the NWS office in Norman issued a message, “Tornado Emergency for South Oklahoma City.” In the opinion of the NWS (even though this contention was not supported by independent published sociological studies after the fact), that message saved lives. It was quickly but informally adopted by NWS offices across the country and the number of “tornado emergencies” increased.

I viewed this as a dangerous trend because for one simple reason:  Meteorologists have no skill — none — at very short term tornado forecasting (i.e., will the tornado lift or continue across a city). Because we have no skill (we use extrapolation) in predicting short-term changes in tornado behavior (movement and intensity), I feared we would diminish the importance of the term “tornado warning” by conditioning people to wait to take cover until they heard the “tornado emergency.” I believe this concern has been validated by the undisputed fact that the majority of “tornado emergency” messages turned out not to be “emergencies” at all.  That is, the tornado lifted or changed direction before reading its “target.”

For all you will ever want to know about both sides of the “tornado emergency” debate, click here.

Now, why do I support Snowicane?  Here’s why,

1.  We have considerable skill at forecasting this type of event as AccuWeather’s accurate forecast three days in advance demonstrated.

2.  The term “blizzard” did not convey the threat of losing power which (I was in on some of the company internal discussions) was a major concern of the forecasters. For someone needing power for, say, medical equipment the ability to get to a hospital during a super-blizzard would be nil. So, we needed to get their attention. Snowicane was a way of doing that as the media quickly picked it up.

3.  The storm moved from east to west like a hurricane and had (when viewed on radar) both an “eye” and a “spiral banded” appearance like a hurricane.  The barometric pressure trace (see the ‘Congratulations’ post) looks like a hurricane and the drop in pressure was similar to a hurricane.

Of course, the Northeast storm had a different internal structure than a hurricane but that is a detail that I think is significant only to meteorologists. The term “blizzard” just does not convey 75+mph gusts with widespead loss of electricity, so I think the use of the term is valid in this case and would be in an identical storm in the future.

Now, there is a valid concern and that is that coining new storm terminology should be done infrequently and with great care.  There is the potential for confusion if this is done too often.  But, in this case, I thought it was done very well.

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