Don't mess with the weatherman

NYC Mayor Bill de Blasio bit off more than he could chew when he tried to blame weather forecasts for his bad decision to keep schools open. Weatherman Al Roker responded, “[De Blasio] says snow was faster/heavier than expected.” “No, Mr. Mayor. It came as predicted. Don’t blame weather for YOUR poor policy.” It is rare when science identifies lying politicians.

Weather predictions are remarkably good because they are stated in terms of probabilities and they can be checked. Those who don't understand this blame the weatherman. If there is a 10% chance of rain, you really cannot blame the weatherman if rain ruins your picnic any more than you can blame the dice you don't roll the number you want. That is how probability works.

Mayor De Blasio bet on a low probability event. He was reckless or stupid to do so. did and perhaps he should learn from his mistake and/or take a course in statistics. His demonstrated inability to understand probability might explain his stance on various fairness and equality issues. A guy like De Blasio doesn't understand diverse outcomes. He really believes it is unfair who chooses seven on a throw of the dice wins more often than one who chooses twelve and if he ran the casinos would no doubt legislate parity of dice throws.

Anyway, it is good that Al Roker kicked the mayor's ass on this. Let's hope the mayor wises up and stops lying.

We wonder if President Obama was just unaware of the probability of "you can keep your policy' comment. We see no sign that Obama ever seriously studied statistics.

We don't believe generally in mandates, but maybe we should mandate that anyone running for public office must have taken and passed a basic course in probability and statistics.

Posted by Christine & John at February 13, 2014 5:52 PM
Comment #376443

As someone who studied both meteorology and statistics in college, I guess this topic is tailor made for me. I understand there will be a tremendous temptation for other commenters to discuss the gamble we are currently taking with regards to anthropogenic global warming, but I’d rather stick to the original topic which is focused weather (not climate).

As per your original topic: you are spot on with regards to the attention that meteorologists place on understanding the actual probabilities involved. Chaos theory was originally discovered by Edward Lorenz during the course of his computer simulations of the atmosphere and understanding how chaos operates has been crucial for the major improvement in forecaster skill made in the past few decades. Nowadays, a really important tool is the use of ensemble forecasting, which is basically the use of multiple computer models running in parallel. Each individual model is fed slightly different inputs and the result is a diverse array of possible outcomes. We can use the distribution and spread of these outcomes in order to quantify how certain our predictions are. Here is an example of such an ensemble. The variable being foretasted is the altitude at which the atmospheric pressure is 500mb, but this particular animation doesn’t depict the actual model forecasts, but rather the standard deviation (ie the spread between the different model predictions) in the ensemble. It allows a forecaster like me to quickly visualize the deterioration in the model’s accuracy as we step forward in time. Watch how when one goes beyond a week or so, the computer models’ disagreement becomes so great that the simulations are mere curiosities rather than actual predictive tools.

Meteorologists have developed such a robust system for dealing with the uncertainties in their forecasts because the very nature of the job means one’s prediction are either verified or not within a matter of days. With that kind of scrutiny, failure becomes one’s best tutor. One example of such a forecasting blunder occurred with the Hurricane of ‘38. The previous hurricane to impact New England arrived in 1824 and was not well documented. Even though atmospheric observations indicated a blocking pattern that was known to cause a landward trek, the hurricane was predicted to go out to sea solely based upon the adage “hurricanes never impact New England”. Unfortunately, the adage was incorrect and millions of New Englanders suffered as a result.

I know Jack has read Nate Silver’s The Signal and the Noise, which I am certain served as a partial inspiration for this particular WatchBlog article. Fortunately, the chapter Nate Silver devoted to the expertise within the weather forecasting community can be read here

Also, regarding Al Roker. Although he is an extremely talented communicator, he is not a meteorologist. It’s probably best that the forecasters don’t need to worry about looking good for the camera or speaking clearly and smoothly, but we shoudn’t confuse the skills of one profession with another.

Posted by: Warren Porter at February 13, 2014 10:40 PM
Comment #376446


Thanks. I did indeed read the Nate Silver book. I rarely remember where my inspiration comes from, but it was probably that.

Good luck in your new job.

Re statistics - I have been developing a management technique based on probabilities and contingencies. It is designed to be robust rather than certain. It has been working phenomenally well in the last few years, so well in fact that people don’t believe it and/or they think it would have happened anyway.

This leads me to a tangent re bad leadership. I can well understand why many people chose to be bad leaders. If you manage a system properly, problems are resolved at appropriate levels and the robust system adapts. The leader in such a system has indirect authority and may be seen to be doing almost nothing at all. The only evidence is that good things are happening. A bad leader doesn’t like this, since it gives him/her “too little credit.” They prefer to be active and in the way, giving commands to subordinates who probably know better what to do, fooling with processes that are in motion. But - to my sorrow - I see such people rise in organizations. Perception trumps reality.

I have been fighting those things, but my fight is quixotic. I foresee that I will lose. I cannot complain personally, but I regret that I have to admit defeat after thirty years.

Sorry for the digression. But I think that politics is generally the sphere of show over results. Politicians like to get involved and seem to be leading and deciding, when they should just let people get along with their work.

Posted by: CJ at February 14, 2014 7:33 AM
Comment #376447

Can’t we just chock De Blasio’s statemenet up as remarkably ethnic, he’s a guinea with a slow wit and jus’ didn’t know any better—ya’ know ‘eh whuh’ gives. I mean these people are witless and stupid, let’s chock it up to that for the good of the Bell Curve, Rudy Giullianni and mankind.

(‘nother dumb child of a foreigner no one can communicate with)

Posted by: simpleheaded at February 14, 2014 9:41 AM
Comment #376448


Please don’t bring your racial/ethnic prejudice to our articles. Also perhaps check your own spelling.

Beyond that, as you may know, de Blasio’s father was of German descent and both his parents were born in the U.S. I understand that you think the man is stupid. I disagree. I simply state that he is ignorant of statistics, like most politicians.

Posted by: CJ at February 14, 2014 10:24 AM
Comment #376449

Thanks CJ, someone left the door open to the computer room again at the asylum is my best guess. Also thanks to Warren for lending his expertise in an educated method to help us all cope with this winter and the predictability of its consequences. I’m just not sure how a posting about weather can get turned into an anti-Obama statement but grain of salt, wink wink, nudge nudge.

Posted by: Speak4all at February 14, 2014 10:39 AM
Comment #376450


I have to put in something political because this is a political blog. My preferred postings about forestry, linguistics, energy or bike trails are just too boring, even for me sometimes.

Posted by: CJ at February 14, 2014 11:04 AM
Comment #376451

Yes but some of us like it, so don’t stop just to satisfy the few who don’t realize the value of widening their perspective. Thanks again and yes politics can also be boring.

Posted by: Speak4all at February 14, 2014 11:22 AM
Comment #376452

President Obama had nothing to do with it.

De Blasio believes government is a babysitting service.

“De Blasio, who won his seat on a populist campaign platform that emphasized narrowing inequality, said that many parents depend on schools to be open because they do not have the option to stay home from work. Poorer children need a safe and warm place to be, where they’re guaranteed a meal, he argued.”

Taking a page from the liberal playbook, this means De Blasio hates kids and wants them to die in traffic accidents.
Why has De Blasio declared war on our children?

Posted by: kctim at February 14, 2014 12:23 PM
Comment #376459

Yeah I guess you are right, I see your point, I mean what if he were black and did that, that would make him an African we can’t communicate with.

Okay here’s my point (all goofy racist stuff aside), that is NOT by any means a menial position (Mayor—ayyy) thus it leaves little room for err, he should have checked with the accurate weather advisory in his area. This is no place to play Fonzarelli—ayy fuh’get about it etcetera go to freakin’ school on yer’ slick roads an’ slip an’ what-not—ayyy I used to walk ten miles to school—ayy—yada yada—ayy.
We do not do what an ethnic leader does here in the US nor do we discuss things the way an ethnic person neglectfully does here in the US either (with a neglectful demeanor about anything).

Aaaaand YES, we publically apologize here in the US too for mistakes especially as Mayor—ayy, I didn’t hear that ever materialize.

Posted by: simpleheaded at February 14, 2014 7:42 PM
Comment #376462


Nobody brought up anything ethnic or racial except you. Nobody here except you even thought of him as an ethnic leader. He was born in the U.S., as were his parents. He went to American schools. Why do you think he is not American? Only you can answer. I sure cannot figure it out.

We recognize that the mayor has a hard job. We would cut him some slack, but he tried to blame his mistake on the weather forecast. It means he is either ignorant or dishonest … well maybe craven.

Posted by: CJ at February 14, 2014 9:41 PM
Comment #376467
Good luck in your new job.

It’s actually just a rebranding of my old job, but no matter the circumstances, I appreciate your words of encouragement.

I also want say a few more words regarding De Blasio. The communication question is definitely one of the big ones currently facing meteorologists today. The reality is that many meteorologists lack the skills necessary to communicate their forecasts to the public. Traditionally, this is where people like Al Roker have stepped in, but the result is that a lot of nuance from the official forecast gets lost when it gets translated into laymen’s speak.

One difficulty that I am aware of is that the public tends to be overly reliant on analogies to recent events. For instance, the New York City region was impacted by two tropical cyclones in the past three years (Irene & Sandy). Irene came in 2011; it was foretasted to cause quite a bit of damage, and it certainly did (my apartment on Long Island lost power for 4 days). However, the impact was quite tame compared to what happened in upstate NY/Vermont. Unfortunately, this event gave a lot of emergency planners false confidence, “If we weathered Irene successfully, then we must be prepared for any tropical cyclones”.

Of course in 2012, the region was severely impacted by superstorm Sandy. I was still a student at Stony Brook University at the time. I remember chatting with a few of my professors a few days before Sandy about how they advising the local emergency managers (including Bloomberg’s team in NYC). It was especially challenging to explain that Sandy was going to be worse than Irene even though it was forecasted to no longer be a tropical cyclone by the time it made landfall. New Jersey, Long Island and New York City were never issued Hurricane watches/warnings by the NHC (or even Tropical Storm watches/warnings) for this very reason.

The computer models showed that Sandy would lose its tropical characteristics and undergo baroclinic intensification about 12 hours before landfall. Typically, tropical cyclones are just heat engines; they simply feed off the warm ocean beneath them, converting all that energy into awesome winds and storm surges. Baroclinic instability is a different mechanism and serves as an energy source for the worst extratropical cyclones impacting New York & New England (namely the fearsome nor’easters that have already brought us so much snow this winter). Unfortunately, Sandy became a sort of chimera, blending the worst attributes of a hurricane with that of a nor’easter.

Because Sandy was technically not a tropical cyclone when it made landfall, meteorologists needed to descriptor that would communicate the unique hazard posed by Sandy. Fortunately, some genius came up with the term “Superstorm Sandy” and after that, the emergency planning went much more smoothly.

Posted by: Warren Porter at February 15, 2014 10:28 AM
Comment #376470


2012 you were at Stony Brook. I brought a group of Brazilian deans up there in 2012. Too bad I didn’t stop by and see you.

Posted by: CJ at February 15, 2014 11:58 AM
Comment #376474
2012 you were at Stony Brook. I brought a group of Brazilian deans up there in 2012. Too bad I didn’t stop by and see you.

I certainly regret the missed opportunity to meet. Hopefully that wasn’t the last. I’ll let you know if I ever visit the DC area. For the time being, I’m still living/working in the Metro Boston area.

Posted by: Warren Porter at February 15, 2014 4:30 PM
Comment #376758

Sometimes, we don’t always get it right.

Posted by: Warren Porter at February 24, 2014 8:30 PM
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