Saturday, May 30, 2009

Prophesying Weather: Thoughts Historical and Contemporary on the Art of Prediction


for Don Anderson, of Summer Passage

...[P]eople secretly assume that he who understands the weather and can forecast it....actually makes the weather...

Nietzsche, Human, All-Too-Human (1878)


There is undoubtedly a cult of the weather in North America. Secretly, we look to our weather forecasters for revelation at least as much as we look to them for interpretation of complex signs and apparitions; they are our preachers, prophets and guides; they peer into the vast mystery and murk of the seas and skies and tell us, as if by magic, what will happen here, or nearby, today and tomorrow.


They segment the winds and take the measure of planetary forces in order to tell us what we’re in for: punishing storms, an excess of heat, a plague of locusts. On land you ask, will it be a good day for golfing, for sailing, for planting, for kayaking? Should we avoid stepping out from a shelter at all? Can we plan a barbecue this weekend or should we clear the decks and pull out the buckets? When you’re sailing you want to know, will this be a good day to head north? Will we be able to sail, or will we be stuck motoring into wind and crashing seas? Is a storm coming; is a major shift in the winds on the way? Should we run for shelter, stay put, or move on? Do we need to set out with one or two reefs; should we plan for lightening; what’s likely to happen next week?


As with any prophetic tradition, some followers of the weather forsake their own judgment and are utterly slavishly devoted to the literal words a forecaster speaks, while others seek to match wits with him (or, more rarely, her), challenging his readings of the signs. Such challenges can be more or less benign on land—No, he’s wrong; I know it will surely rain, I can feel it in my knee, my right index finger, my left big toe. At sea, however, if one miscalculates—oh that wind won’t be so bad, I say 20 knots, not 40—the error can shred your sails, scare the living wits out of you, or put your rig—and life—at risk. Getting the weather right matters; improved weather forecasts have done as much as GPS and accurate charting and life rafts, communications and safety gear all put together to save lives at sea.

*

[T]he tendency of nature to incline or drift away from understanding can be read in the word climate. Derived from the ancient Greek work klima, it refers not only to a latitudinal zone of the earth but also to an inclination or slope. Climate therefore refers to both what falls from the sky and what falls away from understanding. Referring to whatever is incalculable and uncontrollable, it is at times another word for chance and time.
Eduardo Cadava, Emerson and the Climates of History (1997), 5.


Weather is a fact of planetary life. It has been around far longer than human beings have been on Earth; any creature that sucked at the atmosphere has surely been concerned with reacting to, if not foretelling the weather. Every society has developed a trove of meteorological observations, wisdom and interpretive guidelines, from the ancient Chaldeans and Egyptians to the Shang Dynasty in China, more than four thousand years ago.


Regular, accurate predictions, based on systematic surface and atmospheric measurements, and strong understandings of global and regional systems, currents and seasons are however, fairly recent—even if they have their roots in ancient insights—Seneca’s assertion for example, in his Natural Questions, that clouds somehow drive the weather, from rainbows to storms.


We have the Enlightenment to thank for the enthusiasm for careful observation, description and experimentation that has characterized modern meteorology. Decartes, for example, deduced that clouds were composed of water vapour or ice, and in 1802, thirty-year old Quaker chemist, Luke Howard, astonished his London audience by asserting that clouds admitted of regular, fixed and identifiable forms which could be linked with readily identifiable “different states of the atmosphere.” His paper “On the Modifications of Clouds,” argued for three major families” of clouds, and presented a typology that is, if amended, still largely with us: Cirrus (Latin for hair or fibre—describes wispy thin clouds), Cumulus (Latin for pile, heap; accumulation shares the same root), and Stratus (stratum, layer, sheet).


Marion Boddy-Evans, “Types of Clouds, Their Characteristics, and How to Paint Them”at http://painting.about.com/library/blpaint/blcloudtypes.htm


Clouds, Howard argued, shift, unite, dissipate and change constantly, but always in visible, recognizable ways. A taxonomy of clouds allows one to read these variations and their subcategories, to name them and to extract the truth of their shadowy intimations. According to Richard Hamblyn, who has written a lovely little book entitled The Invention of Clouds (2001, Picador), the implications of Luke Howard’s modest December 1802 presentation resonated throughout the 19th century, and changed how scientists, philosophers and Romantic poets and artists from Goethe and Ruskin to Shelley, Byron, Constable and Beaufort—inventor of the Beaufort wind scale— viewed and understood the shifting weather in the heavens. Science could be the anchor and well-spring of inquiry into human knowledge and spirit: classifying clouds did not diminish their mystery, but infinitely increased what one could wonder, observe and understand when studying them.


--As Constable’s infinite-seeming permutations suggest. Hamblyn quotes 19th century commentator, Henry Fuseli’s complaint that “the landscapes of Constable made him want to call for his overcoat and his umbrella” (230).


Edward Morris et al., Constable’s Clouds: Paintings and Cloud Studies. National Galleries of Scotland, 2006.


Ironically—or perhaps fittingly-- the more we know about the weather, the more there is to know—one could spend every waking hour of every day—and some people do—collecting data and assessing it. In the winter of 2008, when Marike and our friend, Jean-Fran├žois Bigras, were bringing Quoddy’s Run from Puerto Vallarta north, into the Sea of Cortez, I spent several hours each day looking at satellite pictures, grib files and current conditions reports, then putting that information together with my knowledge of local conditions where they were and the possible tacks the boat could take, in order to deliver them a weather forecast and voyage advice each day via sailmail from Halifax. (Sailmail is a fantastic program designed to enable sailors underway to send and receive email messages through a single-sideband radio. See www.sailmail.com for more details.) My favourite resource was meteorological site designed for sailors called Buoyweather—you can see what that’s like at: http://www.buoyweather.com/index2.jsp.


It is hard work to collect, assess and distill 12-15 variables across several days into a comprehensive and comprehensible report—a matter of solving for multiple and only partially-known factors at once. It made my head hurt the way advanced math classes had. But it was also fun—and very gratifying when I got the predictions right. For Marike and Jean-Fran├žois’s trip north, (was it luck or proper rigour?) apparently my forecast was spot-on most of the time.


At sea, the challenge is to get a good, accurate local forecast in a timely manner—what you want is a good read on the wind strength and direction, as well as wave height for the next 24 to 48 hours, across the track that you will be traveling. And if any shift or unusual activity is headed your way, you definitely want to know about it, as soon as possible so that you may rush to a safe harbour, outrun a front, or prepare to heave–to. When you don’t have access to the internet, and your path is—as it usually is across the water—somewhat idiosyncratic or erratic—getting an accurate forecast is not a simple matter. Every prediction will be an individual extrapolation based on local knowledge and information available from several sources.


In the US and Canada government agencies are charged with assessing the weather and waters and continuously reporting and updating accounts of coastal and offshore conditions by regions. You can pick these reports up on weather radios if you’re on land (Canadian reports cycle between English and French), or on designated channels on the VHF radio when within range of coast; you can also set up a system for receiving regular high seas updates and weather faxes (via the SSB) from the US National Weather Service, the National Hurricane Center and the Naval Pacific Meteorological and Oceanographic Center/Joint Typhoon Warning Center.


In Mexico, the National Meteorological Service issues regular reports; Port Captains at designated ports on all coasts also announce warnings on VHF radio Channel 16, and give regular daily updates at four hour intervals, usually on channel 12, in Spanish.


Offshore, you must rely on the SSB for voice, text and weather-fax reports. You can also order up simplified text-encoded reports from Buoyweather for specific locations; these are sent at designated intervals via sailmail. Figuring out how to order them—and then how to read them--takes some dedicated practice.


Over the years, we’ve used all of these resources. But we’ve found that anyone sailing the coastal waters from San Diego to southern Mexico in the Pacific cannot do much better than to listen to Don Anderson’s daily weather forecasts. Every day at UTC 1420 (that’s 2:20 pm Zulu or Greenwich time—usually 7:30 or 8:30 am Pacific or Mountain time) on the Amigo net, an SSB “meeting place” for sailors underway from the Pacific Northwest or California to southern Mexico—for ten to twenty minutes Don advises, instructs, hectors, needles and delivers the weather to listeners. All you need is an SSB, and the ability to tune it to 8122.0 USB (Upper Side Band), a pencil, a map, a pad of paper and some patience.


An experienced sailor, racer, and navigator with tens of thousands of sea miles under his belt, Don is also a retired oil chemist and a real weather enthusiast: he estimates he spends nine hours a day combing weather information and developing his own daily report. Born in the UK (in Cheshire, near Liverpool Bay and the Irish Sea), and descended from a line of seafarers, he now lives in Southern California with his very tolerant sailor wife Joan. There, with a bank of equipment and a seventy-five foot antenna tower in their backyard, Don collects and dispenses his weather information. For free. For “fun,” one could say. More seriously, his mission is to save lives.


This may be why there are persistent rumours that he’s a preacher in another life (which one I don’t know; there isn’t much time for that): his style is prophetic, revelatory, teacherly. It can take some getting used to, particularly when the motor is also running and the scratchy, sometimes weak radio transmission strains one’s ears. Nearly every day begins or ends with a “lesson”: it may be a lesson in how to read clouds or what the seasonal currents are or where hurricanes come from or how to read pressure gradients or what is happening in the northwest Pacific or over East Texas, and why you, whereever you are, somewhere in Mexico, should care….


One of his most repeated themes, on the difference between local “land and sea breezes” (also known as katabatic winds) and his weather forecasts, is often served dripping with irony. It is clear that there are many novice listeners out there (we were once among them), who repeatedly hear Don’s forecast as Gospel and are then taken by surprise when a twenty-knot wind whips suddenly out of the mountains in the middle of the night—right, there, where they are anchored! As Don makes clear, you have to learn to read, locally, the interactions between high hot then cool desert land and moderate sea—this is part of good seamanship in Mexico--katabatic winds are not weather, but temperature equilibration.


Occasionally, and sometimes unwisely for listeners cramped in odd positions and straining to hear over the wind or the rumble of the engine, Don strays from his topic—a recent disquisition involved a discussion of self-defense without guns in zones where now, and then, boats are boarded. He concluded his remarks with what seemed to be a semi-serious, contemporary version of Joshua Slocum’s “tacks on the deck” solution: “Of course, you have to remember to vacuum up the tacks in the morning as you go out on the deck yourself!” And then he laughs, a dry ironic laugh: “heh, heh.”


We know a sailor who got so mad at Don and his lessons that the sailor challenged him—by setting out to cross the stormy Tehuantepec when Don suggested it might not be such a fine idea. (When the winds are really high, or likely to be really high, Don is given to understatement. That’s how, if you listen to him often, you come to know he’s really serious about the danger you’re likely to encounter). We tried to stop our friend, but he was headstrong, hellbent on proving a worthy fight with the weather was also a worthy fight between men. We worried and worried and listened to the radio for news of him and his wife. Late the next day they came limping back into the harbour, thoroughly beaten up: boat leaking through every portal and the foresail shredded. Ouch. But alive. Alive.


There’s a reason for all of that preaching and teaching and “revelation” of the secrets of the weather. Don Anderson is literally a “fisher" of sailors, of men and women, a voice crying in the wilderness who offers us, if not salvation, at least some of the tools that we need to save ourselves.


We will go on in Mexico then, listening to and receiving his lessons, many times over (may we never know how many) in his debt. He might not speak the Gospel, but his words are weightier and more valuable than gold.


http://www.csus.edu/indiv/f/foxs/summer%20passage/sumpas_index1.html

2006-2007 Schedule for Don Anderson’s broadcasts, a brief bio, a list of resources and an interview


For a audiovisual tour through some of Constable’s cloudscapes, see the website of National Gallery of Australia, “Constable: Impressions of Land, Sea and Sky” (2006): http://nga.gov.au/Exhibition/CONSTABLE/Default.cfm?MnuID=1

Chart of contemporary cloud taxonomy. The operative division today is not between cirrus, cumulus and stratus clouds, but high, middle and low clouds or regions of the troposphere--the lowest, weather-producing section of the Earth’s atmosphere. Image from http://www.enchantedlearning.com/cgifs/clouds.GIF