Monday, October 08, 2012

Some Possible Tweaks To Severe Parameters Next Year

The National Weather Association annual convention is meeting in Madison, WI this week, with one of the newsworthy changes coming out of the conference in its early stages is the potential for a slight retooling of the severe weather risk categories for next year.

Currently, severe weather risk categories consist of slight, moderate, and high -- these are the common risk categories that are out there, with the infamous "see text" to highlight areas that might see isolated severe activity but below the percentage likelihood of slight.  A photo taken yesterday at one of the workshops yesterday shows a proposal that tweaks the severe parameters a tad.


Say goodbye to "see text" days and hello to marginal risk of severe weather if these proposed changes take hold.

Also, say hello to "enhanced" severe weather days.  More on that in a bit.

First, marginal risks replace the see text that you see on Storm Prediction Center outlooks, with no real changes to the percentages that justify a "marginal" risk day -- between 2 and 5 percent on tornado, between 5 and 15 percent on wind and hail.  These are those summertime days that aren't quite slight risk worthy but do generate the possibility of a severe storm or two.

Enhanced risk is essentially a more aggressive version of the slight risk, with 10 percent odds for tornado, 30 percent odds on wind and hail.  The proposed enhanced risk would be a high end slight risk day if this proposal takes hold.

At face value, I do like the incorporation of a standardized low end category for isolated severe weather days where a few storms could reach severe limits.  It fits the parameter rather well.  However, the use of the term "enhanced" might be a bit strong for that proposed category.  A 30 percent chance of severe weather means there's a 70 percent chance that severe weather does not happen.  Enhanced, in many respects, seems like the odds are higher but for the public it can be confusing compared to moderate risks or high risks, which make a good bit more sense in consumption.  How high of a risk is enhanced after all?

One thought off of the top is to change the marginal, slight, and enhanced risk category terminology -- "marginal" risk is replaced by "isolated" risk, with slight replaced by marginal, enhanced becoming slight.  That would eliminate any potential confusion that the enhanced risk may bring and bring the risk levels a bit more in line with reality -- days with potential for isolated severe weather are accurately reflected as such, with low end slight replaced by marginal and high end slight remaining where it is at.

Tongue-in-cheek for a moment, we could always go the way of Sesame Street and make the risk levels brought to you by a character or two that reflect the color code of risk.  Isolated or marginal risk days could be assigned to Oscar, with high risk days assigned to Elmo.  Of course, this would directly fly in the face of severe weather awareness so such a risk criteria is unlikely to fly -- but at least people would know that today's severe weather risk is brought to us by Bert or Cookie Monster and that it means X or Y.

Thankfully, the "Sesame Street" meme is rather unlikely to fly...unless The Weather Channel decides to name derechos, at which point we may have to worry about Derecho Ernie bearing down on our region.

We will update you on any actual changes that do take place to the severe parameters for next year once those are released.