Communicating Forecasts for Dangerous Weather: Points and Counterpoints

This entry is stimulated by Bryan Norcross’ guest essay in the Washington Post regarding the communication of uncertainty and determinism in the Florida forecasts of Hurricane Irma. Please read this if you haven’t already.

I respect Bryan’s perspective, whether or not I always agree, simply given his extensive experiences in trying to convey the hurricane-threat messages. While doing so somewhat bass-ackwardsly (1-in-1- vs. 1-in-5 or 1-in-3 “odds” as he states), he is arguing for probabilistic forecasting as a solution. Chuck Doswell would appreciate that. Here is a splendid and highly relevant essay by Chuck on weather-hazard decision-making in the face of uncertainty, and another on probabilities in forecasting. Those two pieces also should be “required reading” in this topic.

How those probabilities are translated or expressed don’t necessarily have to be as percentages, or even odds. They can be color fades, categorical labels translated from probabilities, and many other possibilities. It depends on the type of threat and the intended audience. Since intended audiences vary widely, even for the same hazard cause (in this case, hurricanes), and since this source offers multiple *types* of impact threats (wind, surge, heavy-rain floods, tornadoes), the possibilities are numerous. You really need to multiply the threats by the different types of audiences for the information to get the number of ways a forecast can (should?) be expressed. One size does not fit all!

A supply-side effect of taking such an exercise to its logical conclusion is of course a “herding cats” ordeal, where NHC becomes tasked with producing so many different kinds of graphics, texts, and forecast interpretations that the meteorology does suffer…and what good would that do anyone? Meteorological accuracy is at the heart of credibility; without it, all else is useless. Forecasters must not be forced to sacrifice that! Another risk is on the demand side: the “information overload” and head-in-sand or “Ostrich Effect” phenomena.

The bad news is that hurricanes, for their sheer complexity and layers of uncertainty and vast diversity of targeted “publics”, are about the toughest communications nut to crack, front to back. The good news is the same, because once we arrive at better solutions for communicating hurricane dangers, to the most people possible, in the most different effective ways possible, the less-complex weather-hazard producers (heat, for example, or even tornadoes), should be easier to solve from a communications perspective. That’s why I’m glad research efforts and discussion groups like WAS*IS exist, to help to hash these things out.

Still, as a former NHC forecaster and current severe-storms specialist at a different forecasting entity, who has observed closely these developments in the increasingly long time since I left NHC, I can attest that it the hurricane is a nasty hydra — just a big wet multi-hazard mess, tentacles swinging everywhere. Against it we have made amazing progress on the scientific side, but only fits and spurts in terms of COMMS.

Social media is another wild card Bryan didn’t even address, and brings with it a host of challenges in terms of getting the right forecast to the right audience, in the face of lots of rumors, fake forecasts, and non-credible sources.

Another aspect buried in Bryan’s essay, which I’m glad he addressed, is the “limits of science” issue. Excerpt:

    Just about every agency, company, outlet, TV station, website and app — including the National Weather Service, the Weather Channel, and most posts on social media — make explicit weather forecasts of a hurricane’s impact looking days in the future, well before that impact can possibly be known with specificity, based on the modern state of meteorological science.

    These misleading and confusing forecasts are produced by well-intentioned people and organizations because the formats of their text or graphics products demand it. There are seven-days worth of forecast boxes to fill in, so that’s what they do, even though everybody recognizes that the future weather when a hurricane is threatening is unknowable.

As a private-sector meteorologist colleague stated in an offline response: “Essentially we are being required to give a consistent, nearly perfect, 96-hour forecast for these situations because we want people safe (evacuate!) but we don’t want people to spend their scant savings unnecessarily. The problem is, that is beyond the state-of-the-art.

In a nutshell, unreasonable demands for extended precision and accuracy often are made of forecasters, demands for information that lie beyond the state of the science. This hearkens back to something I have been preaching for years, with mixed effect:

We as meteorologists somehow must be willing and ready to state not only what we do know, but what we do not know.

The obstacle we face in doing so is the CYA cop-out mentality, “If we don’t do it, somebody else will”. Problem is, if the “somebody else” is offering “forecasts” that go beyond the reasonable state of the science, they are not credible! Yet that excuse has been used by managers, both government and corporate, to impose duties on forecasters that go beyond what the science justifies. One company produces temperature forecasts for specific days many weeks out — which is totally unjustifiable rubbish!

I am still not convinced, for a less-extreme example, that a day-7 or day-8 severe-storms forecast is consistently skillful or even useful the great majority of the time. Yet a group of forecasters is mandated to put one out every single night, needed or not, skillful or not, solely because the directives say so. Bryan rightly alludes to this dilemma. And on those (exceedingly rare!) occasions when the forecasters can alert to a hazard 9 or 10 days out? There’s no official means for it. Procedure and policy can handicap hazard communication, in this way, in the ways Bryan notes, and many other ways.

James Franklin, recently retired NHC Hurricane Specialist Unit chief, penned this response, also for Washington Post. The response struck me as overly defensive, even as he was making a valid point about the new “Key Messages” social-media product. Here is an example of that product:

I love this new offering, and wish Bryan had acknowledged it better. One valid question: is it enough? Another: what more can be done with limited time and staffing, on operational deadlines? The answers to those questions may compete and conflict! Bryan didn’t address that.

Still, while I understand and agree with much of what James wrote, I did not see Bryan’s article as an attack on NHC — least of all its forecasting — to the extent James did. Instead I saw it as a call for improved messaging of those forecasts, and not just by NHC! In that sense, Bryan’s piece serves a valuable purpose and is not “a solution in search of a problem”. “Key Messages” is a great step. But it’s not the end-all.

More can be done. More always can. But how, and by whom? Those are tricky questions without easy answers!

That improvement role need not reside solely or even largely with the forecasters themselves. The forecasters are educated and trained not as social scientists or graphics artists, but in this instance, as expert tropical meteorologists. They are the best in the world at what they do, bar none. I see the bulk of needed work — and this applies to other hazardous weather types too — as further along the chain of the Integrated Warning System. This means forecast translation and interpretation, both at the place of production and beyond, in media and emergency management, all the way to the responsibility the public audience has to understand what to do and have a plan in place.

Don’t expect the forecasters to do everybody else’s heavy lifting for them. Their job is to produce the most excellent predictions possible, and as I see it, they do.

Why can’t we as a weather science improve how we communicate hazards even more? Figure out additional ways those outstanding expert forecasts can be translated to even better utility once the data that drives the graphics have left forecasters’ desks. The same applies to severe-storms forecasts, as well as winter weather, heat, flooding, and all manner of weather threats. That is a positive goal and an outcome that I hope the meteorology and social-science communities can continue to work together to accomplish.

Scattershooting 170926

Scattershooting while wondering why Mike Stoops is still OU’s defensive coordinator…nevermind: nepotism.


While many on social media are still wasting time playing “masters of the obvious” by sanctimoniously reminding everyone that Puerto Rico and the U.S. Virgin Islands are part of the U.S. (duh…of course they are…and 2+2=4 as well!), real military/governmental aid has arrived, is happening around-the clock, with more on the way. The latter is great news, and a development not covered to such an extent in the sensationalistic, corporate media as in this piece from USNI. The nonprofits (Salvation Army, Samaritan’s Purse, etc.), churches, and NGOs are swarming in to PR and USVI as well, and will remain after the media move on to the latest celebrity “scandals”. But help is happening and more is on the way, even if you are not being told about it. Pragmatically, the help can never be good enough, and the reality is that the scope of destruction and misery are large. Sadly, lives will be lost. The flip side: far more lives are being saved. The lives that are saved don’t get counted and mostly aren’t publicized. Those whose lives are spared by this aid may not even know it. But be assured it’s happening. Please keep donating at the links I provided so it can keep happening.

Winning ugly is still winning. The won/lost column doesn’t include style points. Watching the last 2-1/2 quarters of the hard-fought yet palliative Blue Star win in Glendale against the Cardinals, I was thinking, “this is how we win, whether we do tonight or not…get back to pounding it and keeping them honest with the deep ball!” The Denver debacle partly was the result of an amazing defensive scheme by them, with exactly the right personnel by the Broncos; Bruce Arians was spot-on in that pre-game assessment of the Cowboys. Yet he knew his team didn’t quite have that level of players, and could be worn down — he not-so-subtly hinted at such himself, before the game! And so it went. Recall in Denver how close the first 2-1/2 quarters were before the game got away. It also was a coaching and player-execution problem in terms of wandering astray from a formula that has won the Cowboys over 70% of games started by Prescott and Romo the last few years. The QB should be throwing less, but deeper. Instead of going into details that would be largely redundant with the following, I’ll simply present the following: a good analysis of what turned around and some improvements still to be made from Bryan Broaddus.

There is that moment before the car door slams shut on the hand, or you’re sailing through the air over the handlebars of that bicycle, or those yellow jackets are swarming out of that hole in the ground beside the lawn mower, or that tree limb you thought you ducked enough to miss is closing in fast at eye level, where you realize things are about to get more painful. The flip side is thankfulness it wasn’t worse!

In this masterfully conceived column, Matt Walsh summarizes the problem with the poisonous combination of leftism and liberal Christianity well:

“Christians are “free” to think whatever thoughts they want in their heads (a generous concession, to be sure), and they’re “free” to be as religious as they want while within the walls of designated religion buildings, but anything beyond that is oppressive. Meanwhile, Leftists can force you to make a cake, they can force you to share the bathroom with the opposite sex, they can force you to fund the abortion industry, they can force you to pay for their birth control, they can force all sorts of beliefs and doctrines on your kids in the school system, they can literally march down the street half naked in a celebration of sodomy and hedonism, and none of that can be construed as oppressive. In fact, you’re oppressing them by objecting to it.

“It’s truly amazing that they’ve been able to frame the argument this way. Somehow, they succeeded in redefining “force” as “refusing to do what we tell you.” They were greedy in their lie, and it paid off. Rather than being satisfied with shoving their ideology down our throats and pretending they haven’t shoved it down our throats, they went for the home run and claimed that we’re shoving our beliefs down their throats by not swallowing whatever crap they feed us. And they got away with it. Many Christians have bowed down and apologized for not being quite submissive enough, and now they lay their like beaten dogs, awaiting instructions from their cultural overlords.”

Those are the so-called Christian Left, whose title is literally true when you read “left” as a verb, and who have fallen for (and genuflected to) the idol of worldly cultural fads, while losing sight of divine righteousness.

Maria’s Destruction of San Juan Radar

Recall that when Hurricane Maria moved into Puerto Rico, the San Juan WSR-88D (Doppler radar for my non-weather friends) failed in the outer eyewall. Here’s what resulted:

The dome and antenna blew away to who-knows-where, and the steel framing itself appears slightly torqued. Trees all around are shredded to varying degrees, as should be expected with eyewall winds of an upper-echelon hurricane. The mowed-down trees in the foreground point uphill toward the radar, telling us the wind direction at the time they fell, and part of the source for embedded debris. The image below represents the last 0.5-degree reflectivity data acquired and transmitted before the radar was lost.

Now, thanks to a series of photos from NWS San Juan, two of which I include here, we can confirm why, and apply knowledge gained from damage surveys of other structures (and the Miami radar in Hurricane Andrew) to this weather-sensing structure. That is quite unfortunately ironic.

From available velocity data prior to failure (example below), we know that the radar — which sits high on a hill exposed to stronger flow than lower elevations receive — was hammered by sustained winds over 100 mph and gusts at that elevation near 150 mph. Those winds certainly contained leaves, sticks, and perhaps branches torn from nearby trees. The resulting debris-peppered airstream battered the dome piece by piece and gust by gust, until panels started loosening and coming apart under the combined stress of wind forces and high-velocity “sandblasting” effects.

Once the first panels started prying apart, the flow got inside and the entire dome shredded, exposing the antenna fully to forces for which it wasn’t designed. Being an airfoil, the dish tore away from the base easily and blew away. The entire process of destruction probably took only a few seconds, at most, from initial breach of the panels. To my knowledge, a WSR-88D hasn’t been struck directly by a significant (EF2+) tornado; however, given the windspeeds likely involved in this event, and the wind-resistance specifications of the radar structures (below, source link) one should expect similar results.

A speed of 60 m/s is the same as 134 mph. Of course the failure alone doesn’t prove the windspeed. We don’t know if the radar was built to those specs, nor to what extent the near-certain presence of flying debris played a role. Regardless, can the radar structures be engineered retroactively and cost-effectively against stronger flow?

Of course, the staff at San Juan is dealing with far more pressing matters personally and logistically than missing radar pictures and mechanical engineering of radomes. Still, it won’t help them in their public-warning mission to be without this crucial tool for at least some number of months, depending on how long it takes parts can be scavenged from elsewhere for reconstruction purposes, then shipped in and reconstructed, amidst all the island’s other damage.

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