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WEATHER FORECASTING: MAGIC, ART, SCIENCEAND HYPNOSIS

A. A . Neale*

Presidential Address delivered at the Fifth Annual Conference ofthe Meteorological Society of New Zealand, 10 October 1984.

INTRODUCTIONPrevious Presidents have established a

tradition of selecting for their address a topicclosely related to their particular involvementin meteorology. In my case the topic is weatherforecasting, a subject with which T have beenclosely associated for over 35 years.

It is not unique to spend so long profes-sionally forecasting the weather. From theranks of those who have retired from the NewZealand Meteorological Service, there are anumber who have been involved in this way.Some of those currently employed in the fore-casting service appear likely to do likewise, and

believe that there wil l be many more afterthem.

ADDICTION TO WEATHER FORECASTINGWhat is the attraction that keeps forecasters

at the task for so many years'?It can't be the glamour o f the job; few

occupations have such p o o r promotionalmaterial — there are countless jokes and car-toons portraying the luckless forecaster beingcaught out by the weather.

But, hold on a minute, perhaps there is someglamour coming on the scene in the form ofTV stars presenting the late weathercast. Still,on reflection, this is not supported b y anyclamour of staff to do the evening telecast and'star' on the box.

* M r Neale is Chief Forecaster of the New ZealandMeteorological Service. T h e views expressed i nthis article do not necessarily reflect the viewpointof the N.Z. Meteorological Service.

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Is it the attractive hours of work? Hardly.Few willingly offer to do extra night shifts,and weekend work plays havoc with socialactivities.

Since it's the "getting i t right that counts"with weather forecasts, forecasters can be underno illusion that the public won't hate themfrom time t o time. A f te r al l , even on thebest days one forecast in five is likely to beless than memorable; on bad days the oddsare more heavily stacked against them.

Despite all this, a dedicated team of fore-casters come back day after day, night afternight, year i n and year out, w i t h barelydampened enthusiasm. Why?

The job must have hidden attractions. May-be i t i s i n the 'ar t ' that i s involved, andthe magic, the science and hypnotism. Andthat's not all; forecasting involves a bit of MissMarples and Colombo. as well as a spicing ofour dual national passions: gambling and sport.These could be what keeps forecasters on thejob.

MAGIC - ENTER T H E WITCH DOCTORTo explain this, first travel back with me to

beyond the Golden Age of Greece, when artand science were burgeoning; back to the earlytribal beginnings of the human race. Back tothe t ime when o u r ancestors l ived i n a nenvironment permeated with superstition andthe wrath of evil spirits.

Then, witch doctors held great power. Theycould intercede with the spirit world that hadsuch power over mere mortals. The witchdoctor was held in high regard by the tribe;the position he held was safe provided that

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he was seen to intercede successfully on behalfof the tribe.

When drought threatened the tribe's foodsupply, the witch doctor would need to call fora 'rain dance' to propitiate the spirits, and endthe drought. I n such circumstances, the prob-lem facing the witch doctor would have beento arrange the time of the dance so that therewould be a good chance of rain falling subse-quently. While a few failures could be ex-plained away, i t was imperative that, moreoften than not, rain would follow the raindance.

It is not beyond the bounds o f possibilitythat, during many years — even generations ofwitch doctors through carefully observingthe weather sequences, t h e w i tch doctorfraternity could have come to associate certain'signs' in the sky with the increased likelihoodof subsequent rain. This knowledge could havebeen handed down as part of the sacred andsecret knowledge restricted to the witch doctor,and used to enhance the witch doctor's stand-ing in the tribe.

If this supposition is correct, i t indicatedthe beginnings of scientific endeavour — care-ful observation and association o f sequentialevents. These lead logically to 'rules of thumb'whereby some quite good weather forecastingcan be done; 'red sky at night, shepherds' de-light; red sky i n the morning, shepherds'warning' is one of these.

Hence this could be looked upon as sciencein weather forecasting, but to the tribe as awhole is appeared to be magic.

THE A R T OF FORECASTINGTime now to return to the present, or almost

the present.Not long ago forecasting was an art; in the

19th a n d ear ly 20 th centuries gentlemenscientists carefully observed the weather, com-pared experiences of encounters with storms,and gradually deduced models o f weathersystems.

These models lacked scientific explanationsof what went on in the systems — the way theair moved, rose and descended, etc. Thatknowledge was to come later. In the meantimeforecasts were based much more on art thanscience.

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As aviation developed, so did weather fore-casting. Initially, just as early pilots would fly'by the seat of their pants', so did forecasters;the latter tended to resort to 'imaginative ideas'in their picture o f what happened i n theatmosphere.

In addition to 'imaginative ideas', diction-aries define art as 'cunning'. There may be alittle cunning even today in the way forecastsare arrived at, so there is still some art to befound in weather forecasting.

Art of a different kind is seen in the veryweather maps forecasters prepare. Isobarssweep and swirl majestically across the chartsin an ever-changing kaleidoscope of patterns.Who knows how many potential Van Goghsand Picassos there may be in weather officesaround the world.

With the modern trend to the use of naturalmaterials depicting patterns from nature, therewould seem to be scope for the forecasters'art to surface in carpets and on wallpapers.

THE G I A N T JIGSAW I N T H E SKYWeather reports reach the forecaster from

many sources. Each brings a packet o f in-formation about a part of the atmosphere. I fyou think o f the weather situation as beinga giant jigsaw puzzle, each report can bethought of as being a piece of the puzzle.

When the forecaster receives as many re-ports as needed to give a complete analysis ofthe situation (in other words, receives all thepieces of the jigsaw), then there is no problem.However, even on good days, reports are fartoo few — many o f the jigsaw pieces aremissing. I t is then that the forecaster mustresort to skill, knowledge, experience — evenart — to decide how to fill in the missing partsof the puzzle. A l l too often more than onesolution fits what information is there; but onlyone solution is correct. The forecaster mustmake a choice. This amounts to gambling, withthe forecaster staking his or her reputation onthe choice made.

Even after this first choice is made, furtherchoices follow — some easily, others with ex-treme difficulty. I n effect, the forecaster mustanswer a host of questions: Will it rain? I f so,how heavily? Will there be a southerly change?If so, wi l l i t arrive in the morning, or in theafternoon? How must cloud w i l l there be?Will the morning be windy?

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Should the forecaster hedge his/her bets?Perhaps go for a bit of everything, in the hopeof getting something correct. Forecasts such as"Fine this morning apart from isolated showers.However, in the afternoon showers becomingmore widespread, especially about the ranges"can give the impression that just such astrategy is being followed.

MYSTERY A N D MISS MARPLESGhosts of Maigret, Miss Marples, and their

modern successors, Kojak and Colombo, hauntforecast rooms.

Each weather report contains a piece o fevidence — evidence about the weather. Muchof the evidence from the many reports receivedcross checks, thereby establishing the credi-bility of the reported weather. However, fromtime to time, pieces of evidence seem to betoo far-fetched to be credible. A l l forecastershave known the experience of receiving a re-port which, on first sight, just can't be correct.Then, after a few minutes reflection, the doubtsurfaces: 'maybe the report IS correct'.

This, then, is where the detective streak ina forecaster manifests itself in a continual sift-ing of the evidence in weather reports. Con-stantly there is the trying to f i t i t all into asingle credible picture, and finally discardingthe false clues.

A report is seldom made incorrectly. I t canbe altered unknowingly by the introduction oferrors during transmission from one place toanother. Sometimes a report is credited to thewrong time of day, or the wrong place.

So, just as Miss Marples and Colombo haveto deal with accurate and inaccurate evidence,so do forecasters the world over.

SCIENCE TO T H E RESCUEScience, whose earliest beginnings may have

been linked to what our tribal ancestors sawas magic or the supernatural, really came ofage in meteorology in the 1960s and 1970s,boosted b y electronic computers a n dmeteorological satellites. W i t h t h e i r help,weather forecasting was placed on a muchfirmer footing.

Computers, with the ability to make veryrapid calculations, enabled t h e equationsdescribing the behaviour of the atmosphere tobe solved well before those events happened.

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Prior to the advent of computers, this was notpossible — the events would have occurredlong before they could have been calculatedand predicted.

Even today, though, the equations are notable to tell us everything we need to knowabout t h e atmosphere. F o r t h i s reason,'scientific' weather forecasts by computer arefar from perfect, and forecasters are calledupon to evaluate computer forecasts and, i fnecessary, improve them. Nevertheless the newmethods do greatly aid forecasters by provid-ing types o f information which were no tpreviously available.

Meteorological satellites are providing muchadditional information about the atmosphere.This is taking some, but not all, of the uncer-tainty out o f making up the jigsaw that isthe weather situation.

Indeed, satellites provide much o f the in-formation that comes from the vast oceanicregions which cover much o f the SouthernHemisphere. This enables huge computers atthe European Centre f o r Medium-rangeWeather Forecasts at Reading, near London,to predict with remarkable accuracy the broad-scale wind patterns over the Southern Hemi-sphere up to five days ahead. This sort o fability appears a lmost magical. T h i s i sreminiscent of tribal days when early scienceappeared as a form of magic.

HYPNOSISHow often have you listened to the fore-

cast on the National Radio Programme — theone broadcast direct from the Weather Office— and heard the situation, and the words'Northland' and 'Auckland', and then driftedoff only to 'come to' and hear the ChathamIslands forecast?

The fact that so many people don't hear theforecast for their area must mean that fore-casters possess still another talent — that ofmass hypnosis v ia radio! Many suggestionshave been made over the years on ways toovercome this unintentioned effect. Maybe atrumpet blast, or cannon round between dis-tricts. Perhaps the forecaster could changepitch now and then, announcing "Wake up inWanganui, Manawatu and Wellington, here'syour forecast".

Mood music could be tried; i t could make

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the interpretation easier and help people re-member the forecast i f bars o f well-knowntunes, descriptive of the forecast, were playedat appropriate places. For instance, during aperiod of drought, farmers in particular couldrespond to 'Singing in the rain' when the fore-cast predicts steady rain; for variety Penniesfrom heaven' could be used. On the other hand,during a wet spell, a forecast o f further raincould be heralded by 'Raindrops keep fallingon my head'. Long settled spells would be im-plied by 'Shine on harvest moon'. And so on.

SPORT I N FORECASTINGRemember the Olympic Games? How we

avidly watched the skill of the gymnasts, thespeed o f the athletes and canoeists. To usmere spectators there was the thrill of seeingpeople rise to a challenge.

Forecasters, I believe, are akin t o thesesportsmen and sportswomen. Every day they

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meet the challenge and enter a contest withthe atmosphere: to try and beat the weatherat its own game — to predict what is going tohappen before it actually does.

Each day there is a new 'game' to play.There is no time to become dull and unin-terested, for each game is new; there are noreplays of the same situations.

Two years ago, our Past President, Dr JohnMaunder, delivered an address with the title:The Weather Game. H e noted that manypeople play 'the weather forecast game'. Fore-casters play this popular game al l the time.They know that they can't possibly win al lthe time, but strive to do so most of the time.I believe that it is the challenge and the varietythat is involved in the weather forecast gamethat lures them on, and keeps them at i t formany enjoyable, though sometimes frustrating,years.