Sunday, June 4, 2017

What does "saving the Earth" really mean?

Some fraction of my readers will have seen this bit by the late comedian, George Carlin, about saving the Earth.  George's comedy often consisted of bashing one group or another, showing their hypocrisy or absurdity, and usually incorporated a host of valid points.  This comedy segment seems to make some valid points, but I want to discuss this as if George's monologue were a serious argument, not a comedy act.

When discussing topics related to "Saving the Earth", the meaning implied by environmental concerns is not to "save the planet" for the reason he gives: the Earth will continue, regardless of any damage we're able to inflict. The planet can and likely will "shake us off like a bad case of fleas".  But the human species is poisoning itself with the by-products of our industry, and our garbage.  Look around at all the threats to our environment:  greenhouse gases, oil and toxic chemical spills, release of radioactive materials, lost of habitat for non-human species, the danger to honeybees ... the list is long and diverse. 

If we manage to kill ourselves off by means of damaging the environment, then indeed life on Earth will go on without us, but it will be very different from life as we've known it.  Our absence will be a blessing to most of the surviving species on the planet.  We can't survive without them, but many of them will prosper after we're gone.  Our domesticated plants and animals will adapt to their life without us, or die.  In a few thousand years, most of human impacts on the planet will have crumbled to dust and be mostly invisible.  A new ecosystem will be established and little or no record will exist of all our accomplishments for good ... or that turned out to be harmful

What environmentally-concerned people really mean when they "Save the Earth" is something like "Save us from poisoning ourselves and destroying the ecosystem that sustains our lives."  It's clear that barring extraterrestrial or divine intervention, the only way we can be saved is by our own deeds.  Our children and grandchildren will have to deal with the mess we're leaving them as part of their inheritance from us.  What anger and frustration might they feel for our poor stewardship of what we inherited from our forebears?  We were given the gift of fossil fuels and we're in the process of squandering that legacy on self-indulgence and greed, and there are enough of us now that it's beginning to have an impact on the atmosphere and the world's ecosystems.  The military is concerned about that future world with anthropogenic global warming and its associated ea-level rise.  Many modern businesses have recognized the inevitability of transitioning to renewable energy sources rather than continuing the folly of our dependence on the finite quantity of fossil fuels that remain.  If these very conservative segments of our society are concerned, should we not be?

Yes, George Carlin, species have been dying out for so long as life has existed, but the present extinction rate is approaching that of an "extinction event" and, given the interdependencies we're just now learning about, this can have serious consequences for the human species. As we learn more about ecology, the continuing message is that it's not a choice between us and other species - we depend on them far more than they depend on us.  We don't know enough ecology yet to make detailed predictions, but if non-human species extinctions accumulate at an accelerating pace (which is evidently happening), the impact on humans may well become critically negative at some future tipping point.

If you're just not worried about these things, then you're contributing to the challenges to our very survival we confront ... together!  We'll either address these issues and work together to solve them, or we literally could die off together as a species.  Our transient impact on the planet will be erased and repaired in our absence over a geologically short time interval (a few thousand years).  All the things in which we pride ourselves will decay and disappear; the only evidence remaining will be a deposit of our trash and its decay products, not dissimilar to the thin layer of iridium that marks the boundary between the Cretaceous and Tertiary Periods.  This thin layer rich in iridium in the geological record is evidence of a colossal extinction event that ended the dominance of the dinosaurs and allowed us mammals to begin to become the dominant animals.  Not all that far above the iridium layer,  a deposit of plastic shards, glass, concrete dust, metal oxides, and radioactivity will depict the end of our "rule".   Our exaggerated sense of self-importance may be the source of our downfall.  In this world, there are no guarantees;  our survival literally is in our hands.  Our instincts can betray us. Yes, George Carlin, I worry about a lot of things, and try to do what I'm able to do about it.  Our current corrupt and environmentally-destructive political regime should worry you, too.

I close with the following poem by Percy Bysshe Shelley:

I met a traveller from an antique land,
Who said—“Two vast and trunkless legs of stone
Stand in the desert. . . . Near them, on the sand,
Half sunk a shattered visage lies, whose frown,
And wrinkled lip, and sneer of cold command,
Tell that its sculptor well those passions read
Which yet survive, stamped on these lifeless things,
The hand that mocked them, and the heart that fed;
And on the pedestal, these words appear:
My name is Ozymandias, King of Kings;
Look on my Works, ye Mighty, and despair!
Nothing beside remains. Round the decay
Of that colossal Wreck, boundless and bare
The lone and level sands stretch far away.”

Friday, June 2, 2017

Turning our back on the Paris Accord

The withdrawal of the USA from the Paris Accord has drawn both criticism and support - from different segments of our society.  Many of us felt it was an important first step for the world to join together to do something about anthropogenic global climate change (AGCC).  What we American do or don't do affects everyone around the world.  What goes on in the rest of the world inevitably has impacts in the USA.  We're no longer isolated bands of hunter-gatherers, and so our species has become deeply interconnected and interdependent.  Agriculture set us on the road to this interconnectedness, and industrialization moved us more rapidly in that direction.  Electronic technology is now accelerating the pace of interdependence.  Our withdrawal from the Paris accord is a profoundly disturbing step backward at a time when moving ahead to mitigate AGCC is critical for the future of our nation.

Apologists for this move are saying it was a "bad deal" for the USA.  If global climate change is worrisome to the military in this nation, is it plausible to suggest it's a myth?  If many business leaders supported our being part of the Paris Accord, is it plausible to suggest it was going to hurt the USA economy?  The US military is not exactly a bastion of left-leaning tree-hugger libtards.  Business leaders don't advocate things that will be bad for their business.  There are abundant examples now showing that reducing our dependence on fossil fuels will not bankrupt our economies, but rather will energize them.  As new technology is developed to replace the old, new jobs will be created and the economy should prosper.  In various places around the world, including American states, this is already happening.  The hard part is the transition period as we wean ourselves from fossil fuels.  To step backward away from the leadership of a movement to mitigate AGCC, will cost our nation in many ways, and is not the path to American "greatness".  It delays the inevitable transition, making the pain of transition last longer.

I'm not a climate scientist, so I have no evidence of my own to support or refute the reality of AGCC.  I defer to the consensus of my scientific colleagues who are doing global climate research.  Would you entrust your health care to someone not a medical doctor?  Would you entrust your safety to a person who has no pilot training or experience?  Why do you lend credibility to non-specialists in issues of science?  Why do you think you know as much or more about the global climate as the consensus of climate scientists?  On what basis can there be such intense political opposition to the climate science consensus about AGCC?  Insofar as I can tell, only a tiny fraction of global climate scientists are arguing the consensus is wrong.  The rest of the chorus of voices opposing efforts to do something about AGCC are not global climate scientists, but are mostly basing their position on propaganda, lies, distortions of the facts, and political machinations.  Opposition to the Paris accord is just another rearguard action against a future technology shift toward renewable energy sources that is already well underway, even here in the USA.  Opposition to progress appeals to those who feel threatened by global unity in the face of global challenges.

The current political situation in the USA is going to result in damage that will take decades to repair.  The regime in power is anti-science, anti-intellectual, supportive of creeping theocracy, contributing to the massive expansion of the income inequality gap, alienating our international allies, devastating our public education systems, encouraging xenophobia and bigotry, and on ... and on ... and on.  Each day, more damage to America is happening, so withdrawing from the Paris Accord is another step down a very destructive path for America. 

Some have said that politics is intruding into science and that isn't good for the science.  AGCC didn't become politicized by some sort of conspiracy among climate scientists.  It became politicized when it became clear that something needed to be done about the threats posed by AGCC.  There would be a price tag attached to any efforts at mitigation of AGCC, and where money is involved, there go some politicians and their corporate sponsors.  And many political conservatives wax eloquent talking of the doom associated with progress.  It's what they do - oppose progress.

Thursday, June 1, 2017

Tornado chasing versus storm chasing

Now that spring is well underway, I've observed an increasing tendency for many chasers to be focused totally on tornadoes.  In a way, I can understand this obsession, as I've had a mild form of it all my life.  I wanted to see a tornado for many years before I saw my first on 30 April 1972, near Mangum, OK.  As a chaser, I've chosen not to keep count of the number of tornadoes I've seen.  I don't see the experience as a means to increase the number of tornado notches in my metaphorical gun.  One reason for my choice not to keep count is I detest the notion that one must compete in some sort of machismo contest about who's seen the most tornadoes.  There has always been some tendency for some chasers to seek some sort of mythical crown as the king of chasing.  But it's not my reason for chasing.

I also find that what I see in storms doesn't always allow some uncontestable enumeration of how many tornadoes I saw.  This may or may not be cleared up in a post-storm survey.  Given the vagaries of chasing, one doesn't always have the luxury of being close to the action for the duration of an event, so what may seem to be separate tornadoes may just be gaps between observations of a continuing tornado.  Or it may be a real gap between distinct tornadoes.  It's not always easy to be sure. Tornadoes change their appearance rapidly sometimes and their evolution can include such complications as rapid dissipation and re-forming, satellite tornadoes, etc.  I've discussed some of this here - storms can get complicated in a hurry, making tornado counts problematic.  Hence, when someone says they've seen XX tornadoes, I always have a nagging doubt about their numbers.  So I don't even try to keep track.  Or I just make my best guess in the complex situations, without necessarily having much confidence in the number.  If someone wants to brag about how many tornadoes they've seen, that's up to them.  It's not something I want to do, at least in part because I'm never absolutely sure how many I've seen (in multi-tornado episodes), and in part because it just doesn't matter to me.

Nowadays, chasers are so tornado-focused, they apparently consider any chase in which they fail to see a tornado to be a total bust.  Moreover, they go to extreme lengths to see a tornado - such as going into the "notch" of an HP supercell to check out the possibility of a rain-wrapped tornado, or "core punching".  Apart from taking what I consider to be foolish risks just to see a tornado, they often then proudly post shaky, poor contrast imagery wherein a tornado may be just barely visible, if at all.  Evidently, showing imagery of a tornado, no matter how amateurish it may appear to be, is the most important goal of chasing for some chasers.

Moreover, I guess I've seen enough tornadoes by now that I've become rather circumspect about my images.  A nearly monochromatic shot that shows a dark, backlit cone tornado certainly may document the event for a tornado-count person, but I find them pretty uninteresting.  Same goes for poor-contrast and/or blurry images.  They might serve the purpose of documenting the tornado count, but I just can't get all worked up about imagery of that mediocre sort.  I suppose I've become a bit jaded, at least in this limited sense.  If I see a tornado, even a non-photogenic one, I'm still excited about it, but if I'm going to show off my imagery, it's not going to be like a lot of what I see posted on social media - boring backlit silhouettes, shaky video, low contrast, etc.  In fact, if I don't see a tornado, but I'm able to catch a great lightning show, or see the dramatic structure of a striated supercell storm, I'm just as pleased as if I've seen a tornado.  [I also love images that draw attention to the setting where Plains tornadoes happen - chasing has given me a love affair with the plains and its people, even when there are no storms happening.]  And I don't experience any particular compulsion to court disaster by being as close to a tornado as possible.  Recognition that I'm in the path is virtually always a signal to me to move!  No tornado is worth my life or the life of someone chasing with me.

These days, in certain situations, the chaser hordes are a major concern.  Many horde participants are tornado-obsessed, so they want to get into the "bear's cage" to the maximum extent.  Therefore, one can reduce the impact of the hordes by staying back a few miles, which I usually try to do.  It's not so crowded and, many times, the structure of the storms is far more interesting (at least to me) than some non-photogenic tornado.  I'm no longer a tornado chaser, but a storm chaser.  I'll welcome any tornado opportunities, of course, but that's not my only reason to be out there chasing.  I've never felt the need to be the world's best tornado chaser, nor do I see it as necessary to chase every possible chase day in and near Oklahoma.  I suppose this is the result of 45 years of chasing.  My original goals as a chaser have all been fulfilled, and adding more layers of frosting to the cake doesn't necessarily make it better.

Sunday, April 23, 2017

Earth Day and the March for Science

We didn't participate in the OKC March for Science - mostly because we're still recovering from our recent respiratory problems.  I'm pleased to know it was reasonably well-attended and our absence only subtracted a negligible portion. 

The widespread disrespect for science within the Trump regime and inside the halls of Congress is a component of a national malaise that didn't begin with Trump.  This trend could bring our secular democracy down.  If we lose interest in the facts, preferring lies, myths, slogans, and propaganda to a fact-based, logical understanding of the world in which we live, then our destiny is to become a second-rate nation, perhaps sliding farther toward third-rate, or worse.  A societal ambience that devalues education, science, and civil discourse is likely to fall prey to authoritarianism.  Facts will be ignored or distorted, as myths and superstitions will hold sway.

Contrary to what many people say, science is not a belief system, in the sense that science does not depend on a particular set of beliefs that are untestable and beyond question.  Scientific facts don't depend on anyone's beliefs;  whether you "believe in them" or not doesn't change the truth of their being facts!  Science uses logic and evidence to propose explanations for why the natural world is observed to be the way it is.  Experience has demonstrated repeatedly that logic and evidence work to achieve increased understanding.  Scientific explanations are always provisional, never final or "settled" in some way.  You don't have to accept them as a belief system, because they work!

Explanations based on evidence always are subject to re-evaluation and possible revision in the face of new evidence or when another explanation is proposed that does an improved job of explaining the facts as we know them at any given moment.  You certainly can choose to believe or not believe the explanations that science offers, but you can't choose to believe or not believe in the facts that were used to support an explanation.  If you disbelieve in a scientific explanation, what's your alternative explanation?  The more rigorously an explanation has been tested (often by collecting new evidence), the more likely it is to be an acceptable hypothesis.  Some ideas have been tested so many times and so thoroughly, the consensus among subject matter experts is that they go beyond a mere hypothesis to the level of a scientific "law" or "theory".  Note that the use of the word "theory" is not like some barroom conversation where someone says "I've got a theory about that!"  A scientific theory (e.g., Einstein's Theory of General Relativity or Darwin's Theory of Evolution) is a thoroughly vetted explanation.

Given those explanations of how things work, science permits the exploration of further ideas based on those explanations; if we accept an explanation, what other things can be implied using that explanation?  Validated explanations are the foundation upon which technology is built.  The fact that our technology works the way we have come to expect it to work is mute testimony to the solidity of that scientific foundation.  Our society has come, for better or for worse, to be based heavily on technology.  Those who deny the validity of science are, at their core, either (a) uncaring about the negative impacts of undermining support for science and more concerned about power or profit, or (b) they're so profoundly ignorant, they fail to grasp the significant parts of what science has given to us.  Possibly both may apply.

The evidence has shown that investment in support of scientific research is repaid many times over by the value created as a result of that research.  Yes, there are some scientific projects that seem awfully far removed from any practical application.  And no, not all scientific projects are destined to become important.  But overall, our position as a prosperous world superpower has been made possible in part by the large investments we've made over time in support of science.  Skeptics should review the book "Science - the Endless Frontier" written by Vannevar Bush after the end of WWII.  Sometimes, the most seemingly useless and impractical hypotheses can turn out to have some purely unexpected value that no one anticipated when the original research was done.  In some cases, it might be many years before some piece of research comes to practical fruition.  To limit science only to those topics that can be of immediate value is to cripple the science in the long run.  We as a nation have become obsessed with the short-term "profit and loss" analysis, and many topics that might prove valuable in the future are not being pursued for lack of funding.

Unfortunately, science is becoming a casualty in the political wars being fought over whose ideology is going to run this nation.  Topics like global climate change have become tainted with the miasma of politics, to the point where scientific facts are being denied or grotesquely misused to serve this or that political view.  This has put our nation's leading position in science at great risk.  If we fall victim to that apparent tendency, then we're doomed to fall from our world leadership position and slide down the slope toward scientific mediocrity and dependence on others to do our science for us.

This year's Earth Day March on Science around the nation is a reflection of the concerns within the scientific community for what we see happening to devalue science in our society.  Sure, it has some roots in concern for our jobs.  But of all the careers someone might pursue, I know of no scientist who chose to become a scientist purely for the profit motive, and most of use are not counted among the rich.  What we possess in abundance is a concern for the importance of truth and evidence-based critical thinking in the USA.  That's worth marching for and not based solely on our self-interest!

Monday, April 3, 2017

Wordsmithing the watches and warnings is not the path to improvement

Hard on the heels of some unnecessary storm chaser fatalities, now social media are calling into question the use of the "particularly dangerous situation (PDS)" wording in watches, and the so-called impact-based warnings (IBW) that use terms like "tornado emergency" in them.  I expressed my concerns about the initial IBW experiment a few years ago, here and here.  The juggernaut of IBW has rolled on, nevertheless.  A recent situation involved an event with a tornado headed toward a big city that triggered a "tornado emergency" warning, but the tornado dissipated soon thereafter, doing only relatively minor damage.  It's precisely this very uncertainty about tornado tracks and intensities that makes warning forecasters agonize over their decisions.  And people in the "general public" often get upset and some inevitably start whining about "crying wolf".  [I've never understood the mindset of people who become upset about not experiencing a major disaster!]

The big issue is now, and always has been, the challenge to convey uncertainty in a way that people understand the reality of the difficulties we face in issuing storm forecasts, so their decision-making actually will benefit from the added uncertainty information.  A major obstacle we face is that we as yet have no large dataset derived from interviews with a representative sample of the public.  In the absence of such information, we're reduced to guessing how to improve things.  NWS management feels the pressure to respond to the growing number of people who advocate the involvement of social scientists.  Instead of supporting extensive survey efforts to create that representative sample, all we get is hollow talk and ill-considered management decisions, like the IBW experiment.  There remain many questions to ask in surveys:  How is the current system working?  What do people consider to be a "false alarm"?  If we include uncertainty information, what's the most effective way for that information to reach and be understood by the most people?  What if we had a component in our watches and warnings that caters to reasonably sophisticated users (like emergency managers) and a different component to reach the broadest possible audience?  A watch or warning doesn't have to be either X or Y, after all - it could include a multiplicity of options.

Personally, I don't believe that wordsmithing watches and warnings is likely to be very productive.  Words have a nasty and virtually inevitable tendency to mean different things to different people.  No specific choice of wording is ever going to be universally accepted.  Even within a limited region of the nation, the diversity of the "general public" represents a serious challenge.  Further, constantly-changing technology within the "social landscape" causes that landscape to change constantly, as well.  What worked in the past may not work so well today or in the future.  This isn't a one-time challenge we can solve forever with one big push. 

We're beginning to realize that the use of PDS watches (and "tornado emergencis") may well result in people seeing "ordinary" watches as something less important than those given the PDS label.  The verification of PDS watches is somewhat better than that for regular watches - evidently there's some skill in making the choice to use (or not use) the PDS designation.  The "tornado emergency" form of the IBWs doesn't have a very good verification track record at all.  There are just too many storm-scale uncertainties for this product to exhibit much skill.  Its failures stir up controversy and there's no hard evidence to suggest that the IBW system has been a successful solution to conveying uncertainty.  What people like or don't like doesn't necessarily track with what actually works to bring about some desired outcome.

That brings up another challenge:  What's the outcome we desire?  Do we really want to be telling people what to do, and seeking a magic bullet to make people do what we want them to do?  Personally, I believe telling people what to do, say via "call to action" statements (CTAs) is not a good idea.  What people need to do depends on their specific situations, about which we as forecasters know nothing!  People should develop their own specific action plans to meet the situations they're likely to experience in a hazardous weather situation (at home, at school, at work, on the road, engaging in recreation, etc.) well in advance of the weather actually developing.  With severe convective storms, there isn't time to make such preparations when the storm is minutes away.

It's no secret that probability is the proper language of uncertainty.  It's the optimum mechanism for conveying confidence in various aspects of the forecast.  For an example of probability-based forecasts, I encourage people to review the "severe weather outlook" products from the Storm Prediction Center as an example of how to show what I call "graded threat levels" - the probability is derived subjectively and is associated with the confidence the forecasters have about their threat forecasts.  Big numbers imply high confidence, small numbers imply low confidence.  They actually have different probabilities for each of the three severe local storm event types:  tornadoes, hail, and strong winds, and they distinguish the cases with a threshold level of confidence for "significant" severe weather:  EF2+ tornadoes, hail 2+ inches in diameter, and winds of 65+ knots.  This is not just a black-and-white statement that some event will (or will not) happen - it's a complex picture that forecasters deduce from all the information they have.  There's a rather similar but less complex system for the severe thunderstorm and tornado watches.

This sort of product is what we need to develop for the short-fuse threats associated with warnings, but the difficulty I foresee with that is the rapidity with which severe convective storm threat probabilities change - they can increase or decrease markedly in a matter of a few minutes!  It would take a very close monitoring and updating procedure to capture the variability of the threat, and even if it's technically possible to do (say, using automated algorithms), with the threat changing so rapidly, would users find that helpful or simply confusing?  I suspect the latter.  The recent event referred to above exemplifies this challenge.  With a tornado headed toward a city, the "tornado emergency" call seems pretty obvious, but the reality is that the threat vanished in short order and the resulting forecast sure looks like a false alarm.  The threat was real, but it wasn't realized because of uncertainty in the storm.

We have lots of work to do, and are not well-served by hasty decisions made more or less in ignorance of the relevant facts, both in meteorology and in the social sciences.  The existing system has worked well for decades, despite its imperfections.  If we make changes, let us be confident we aren't making things worse, rather than better!

Wednesday, March 29, 2017

More on "extreme" storm chasing, part 3

Another tragic storm chasing incident has occurred:  a traffic crash on rural roads in the Texas Panhandle.  There were three fatalities - 2 in a vehicle that ran a stop sign, and 1 in the vehicle into which they collided.  All three victims of this were storm chasing at the time.  I wrote about an eerily similar incident that happened in 2015, here.  The evidence is mounting that being on the highways is indeed the most dangerous threat to chasers (and others).  I wrote a guide to safe, responsible storm chasing decades ago, and I rated being on the roads as the #1 threat before anyone had been killed.  At least 7 people have died in road wrecks during storm chases, that I know of.  Additional fatalities are inevitable.  It only takes a few seconds of inattention to the task of driving to result in terrible consequences.

I am not somehow invulnerable to all this.  I could be distracted by something while driving on a chase and be responsible for a fatal crash.  Like the tragedy of the 31 May 2013 deaths of the Twistex team:  Tim and Paul Samaras, and Carl Young - bad things can happen to anyone, even someone trying their best to behave responsibly.  However, these recent traffic fatalities both involved a chaser running a stop sign.  It might be possible to do so in relative safety on a rural road, but even on rural roads, it's both illegal and foolish to do.

These are unnecessary deaths.  The so-called "chase community" (which really isn't a "community" at all, but rather a group of people with a shared hobby) needs to take a long look at their behavior during their chase activities.  If someone has done some irresponsible driving in the past, this might be a good time to resolve to discontinue such practices for good.  This is the 2nd recent wake-up call, folks.  The time is long overdue to get serious about ceasing illegal and unsafe driving during a storm chase [or any other time, for that matter!]  No one gets a free pass on the roads, and this includes people chasing for TV.

Supplement:   Some news media have gone into attack mode on storm chasers as "thrill-seekers" as a result of this tragedy.  If someone can witness the grandeur and beauty of the atmosphere and NOT get an adrenaline rush, I would have to wonder for what reason they're chasing.  I see no problem with being a thrill-seeker - as I noted in my 2014 talk at ChaserCon. That doesn't mean we all have a death wish or are intentionally putting ourselves in imminent danger.

The media narrative they always pre-suppose is that the people who do this are all crazy fools with a death wish. They struggle to grasp why people choose to chase and their pre-supposition blinds them to what chasers actually say. They look for a sound bite to support their already-written storyline about crazy storm chasers. Their usually crappy stories show they don't get it and likely never will ... see here

Friday, March 24, 2017

What does the public want from a weather forecast?

Note ... this is a slightly modified re-post of a guest blog here.

I’m among the first to complain about people offering their opinions about what “the public” wants from weather forecasts, rather than collecting evidence through a process of literally asking a representative sample of people.  However, the latter is not something easily done.  “The Public” is not a homogeneous block of people with equal needs and expectations.  Rather, it’s quite diverse and it’s not obvious to me even how to go about collecting a sample that might be accepted as representative (by those whose expertise is in doing such surveys).  There are some social scientists who have such expertise, I’m sure.  I might even know some of them.

Nevertheless, I’m going to go ahead and offer my unvalidated opinion regarding this issue, anyway.  I’m working with the notion that “the public”  in this context excludes all meteorologists and those who already are adept at using weather forecasts effectively.  My perception is that most people don’t pay much attention to the weather most of the time, and know little or nothing about how it works, or what we meteorologists can claim legitimately to know about the atmosphere.  When they hear a forecast, if they think it might actually matter to them on a particular day (for whatever reason), they want the forecast to be perfect so their lives will be spared (if hazardous weather is possible) and/or they won’t be seriously inconvenienced by the weather as they go about their business.

Regrettably, forecasters never know with absolute certainty exactly what’s going to happen – high uncertainty typically is present on a day when the weather is changing rapidly.  I’m not going to go into a long-winded discussion of the sources for weather forecast uncertainty, but they generally arise from the fact that the weather evolves from some starting structural state to some other state according to atmospheric physics that we know only imperfectly.  We don’t even know the starting point with absolute accuracy.  It’s sort of like putting together a complex itinerary for a trip, where we don’t know exactly where we’re starting from, and we have incomplete and imperfect knowledge of how the transportation system operates.  We will almost certainly wind up in a different place than what our original destination was thought to be, although in the case of weather forecasting, it usually turns out we come fairly close most of the time, despite being forced to use incomplete information.

Wanting forecasts to be perfect is natural and very understandable.  We think our own lives are too complex to be completely and accurately predictable, but if we can rely on the weather forecasts to be perfect, it makes our decision-making a lot easier.  Re-schedule that picnic if it’s going to rain.  Water your garden if it’s going to stay sunny and dry.  Go to the pharmacy to refill your prescription before the heavy snow flies.  In fact, this is just what's happening on most days as a result of the existing imperfect forecasting systems we use – people can and do make use of our forecasts for just this sort of decision-making despite the imperfections of the forecasts.  If someone makes a bad decision and everything goes bad for them because of the weather, they can always blame the damned forecaster!  Some surveys I’ve seen make it clear that many in the public know and understand our forecasts aren’t perfect, but still some people become upset when the weather doesn’t follow precisely what they heard in the forecast(s).  Note that in the real world, one thing forecasters do is to update their forecasts based on new weather information.  Hopefully, it won’t come as a surprise to most people that our forecasts get worse, the farther ahead they are predicting.  Conversely, we improve as the “lead time” gets shorter.  Don’t expect the forecast for weather a week in advance to have the same level of accuracy as one 12 hours in advance!

When the forecasts are changing frequently as a result of new information, this is usually because of large uncertainties on that day.  Not all days are equally difficult to forecast, of course; our forecast uncertainty is not a constant.  In fact, our uncertainty is also not perfectly predictable!

Let me tell a personal anecdote that I’ve used often to illustrate the value of knowing and using the uncertainty information in a weather forecast.  Some years ago, on a fall football weekend here in Norman, there was a slow-moving, strong front in the OKC area (about 20 miles north of Norman).  On the south side of that front, skies were mostly clear and temperatures were expected to rise into the mid-70s (in deg F) in southerly winds, while on the north side of that front, skies were overcast with low clouds and rain with temperatures in the upper 30s or so, and a strong northerly wind.  It was about equally likely the front would stay north of Norman or push a few miles south of Norman by mid-day (around the time the game kicked off).  The forecaster didn’t have the option of saying that the weather that day had about a 50% chance of either option, so the forecaster was forced to make a choice.  As it turned out, the forecast decision that morning was for warm and sunny, whereas the real weather turned out to be miserably cold and rainy.  Tens of thousands of football fans were caught in summer clothing because they accepted the forecast, and they were not happy!  Since I understood the situation, I dressed for the warm option, but carried cold weather rain gear in my backpack.  It was a simple matter to prepare for both possible outcomes!  I’ve often told this story and then asked the audience:  “Would you prefer to be offered the whole story of the forecast, including the uncertainty, or do you just want the forecast without any uncertainty information?”  I almost never get anyone who chooses the latter option!  Is that surprising to anyone?  Nevertheless, many people just want to know what’s going to happen, even though most of them understand the science doesn’t allow them to have absolute certainty.

Every forecast that doesn’t include uncertainty information is tantamount to withholding critical information from the public!  And the public needs to accept some responsibility to learn how to use that uncertainty for their own purposes – they have to set their own thresholds regarding uncertainty.  If the worst thing that could happen to you is getting a little wet, you can accept more uncertainty than if you stand to lose your life if some hazardous weather potential exists.  Unfortunately, low uncertainty, highly confident forecasts are just not possible in some situations.  We can’t predict precisely the path and intensity of a tornado, so a tornado warning generally always has relatively high uncertainty.  The same can be true for deciding just when and where winter storm weather will occur.  From a meteorological standpoint, getting the heavy snow band to within 50-100 km of its eventual location is an excellent forecast.  But that might mean the difference between heavy snow mostly in rural areas versus in a major metropolitan area.  Expecting that forecast to be perfect is just asking to be frustrated.  People can want a perfect forecast, but people in hell want a glass of water, too.  Are they going to get it?  Nope.  Likewise for perfect weather forecasts. 

C’mon people!  You know we can’t make forecasts with absolute certainty, so why keep complaining when it turns out we can’t make perfect forecasts?  The forecasts have been improving steadily, and are much better than we were even 10 years ago. The public is being well-served, as I see it.  Where we have a problem is communicating our uncertainty and the public is remiss in not working very hard in trying to learn how to use any uncertainty information we do provide.  It would be nice to figure out this bottleneck.  Sadly, I have no easy solutions to offer.