Jumping to conclusions about a forecast is a bad idea 

Posted: 3:00 am Thursday, September 20th, 2018

By Kirk Mellish

Confusion on FLORENCE Category is all wet.

Many correct forecasts receive a poor response from some members of the public or some members of government, even from news people and show hosts. We see it all the time, whether it’s winter weather, spring tornadoes, or hurricanes.

Reminds me of one of our snow/ice storms over the past 5 years here in Atlanta when some people and some government authorities thought a change from a Winter Storm Watch to a Winter Weather Advisory was a downgrade. It was and is not. The forecast and the forecast impacts had not changed, but people jumped to their own conclusions and made their own forecasts up in their minds, as a result they stopped listening and reading forecast details and let down their guard.

Now we find some people made THE SAME MISTAKE with Florence.

The 1971 “Saffir-Simpson Scale” for rating tropical storms and hurricane winds DOES need to be replaced or augmented by something that takes more into account a storms overall size, power and expected impact!

That said, two of the three biggest storm hazards, wind damage and storm surge, are highly correlated with wind speed – which the Saffir-Simpson Scale accurately characterizes. (Note: the storm surge is a primarily a function of wind speed and coastal characteristics [forward speed and wind radius are also factors].)

Sadly even too many people in the broadcast news business and newspapers don’t get they should not focus so much on wind category.

I hope people heard me on the radio in our special coverage emphasize “water not wind”. The wind has been “downgraded to a Cat 1 but the impacts will be more like a 3”.

I also blogged about it and emphasized the “relative” UN-importance of the max winds because “they are a tiny fraction of the storm near the eye while negative impacts will extend hundreds and hundreds of miles”.

The NHC hurricane forecast experts did a good job of forecasting intensity changes until  it got near the coast when the winds weakened more than originally projected. They never said that changed the flood dangers. They nailed the track and rain forecasts.

The forecast track was remarkably accurate from as many as 7 days out. And critically forecasts for “catastrophic and life-threatening flooding” were on the money 5-7 days in advance, and those forecasts NEVER changed substantially:

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A lot has been made in the news in recent days about how people decided not to evacuate or to return based on hearing the storm had been downgraded to a 2 or a 1.

Hmm, the forecast dangers from storm surge and flooding were never downgraded so this is not on forecasters in the Carolinas or the NHC, it’s on the people who jumped to their own conclusions and did not pay attention to the ongoing forecasts for destructive, record breaking, life-threatening conditions which never wavered.

Trust the experts. Nobody’s perfect but experts are far better than guessing or assuming. Never trust social media shares. Personal Responsibility and being an adult is important in life.

And don’t forget the tornadoes that are common with landfalling hurricanes and tropical storms:

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What is more, the idea that the wind is less important and the ‘Category’ should not be a focus is hardly a new thing. When our News Director asked me to comment about this I found this in my Microsoft Word program from show notes I used back in 2011.

I’ve been making this point-on air and in my blogs for decades. You can provide information to people but you can’t force them to listen to you, read you or absorb the info:

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POPULAR SCIENCE Magazine did a great story on this about deadly ‘minor’ storms.

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A lot of weather info is available on the internet for free, and a lot of armchair experts post weather maps they don’t understand on social media like Facebook etc.

Forecasters worry that users often misinterpret individual pieces of data or second-guess official forecasts. They then make decisions based on rumors and a confusing barrage of unofficial forecast info. Then if they guess wrong you know who they blame.

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This was from the NHC  a week in advance on Saturday Sept 8 11am:

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The next day Sunday September 9th 11am they upped the ante about “life-threatening flooding” and they never backtracked thereafter… 6 DAYS IN ADVANCE:

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The key messages just got worse from there every 6 hours. And 5 days out the track was on point:

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They were warned.

Here are just some of the blog posts I made and when:


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Here is what Dr. Shepherd of UGA had to say about it in a Forbes article.  

Communication is tricky with the complexity of storms.

Hurricane misconceptions.

FOLLOW me on Twitter @MellishMeterWSB.