by David Laskin
Or rather it would be over the northern tier if it flowed in a straight line, but in fact the jet meanders around the world in a series of immense loops, each of which spans some three thousand or so miles. These loops, or long waves, as meteorologists call them, form as the jet gets squeezed or stretched by the prominent irregularities on the earth’s surface, like major mountain ranges or the ocean basins. Typically, three to five long waves are slowly moving and evolving around the earth at any given moment. As these waves interact with the jet stream that flows through them, great eddies of air known as cyclones (lows) and anticyclones (highs) spin up, which themselves warp the whole pattern of waves. High pressure at the surface, which is associated with warm air aloft, creates a poleward bulge in the flow called a ridge—an arc that slopes to the north on its westward flank, peaks at the top of the high, and then descends southward; similarly, low pressure at the surface, associated with cold air aloft, sends the jet plunging south in an arcing trough that bottoms out around the base of the low. When forecasters speak of a “ridge of high pressure” or a “trough of low pressure,” what they’re talking about are the peaks and valleys of the long waves that distort the west-to-east progress of the upper flow. Each long wave is measured by its wavelength (the distance from ridge to ridge and trough to trough) and its amplitude (how far north or south the loops are deflected).
During the first week of January 1888, as Etta Shattuck was teaching her last day of school in the Bright Hope school district and Anna Kaufmann’s three older sons were dutifully walking back and forth over the hard-packed snow to Mr. Cotton’s schoolhouse and eight-year-old Walter Allen was studying his fool head off in Groton, a dome of intense high pressure in western North America buckled the polar jet into a high-amplitude ridge. This pattern might have hung in for a week or more before the long wave drifted away or gradually weakened, and we never would have heard a thing about it. The reason it didn’t happen this way is that a sudden shot of energy surged into a segment of the jet and caused the core of the current to accelerate rapidly—like a bullet train rocketing through a tunnel of air, a tunnel that is moving as well in the same direction, only more slowly. This atmospheric bullet train is called a jet maximum or jet streak. It’s hard to pinpoint exactly how and when a particular jet streak takes off, though there are several scenarios typically at play. Six miles above the Arctic, vortices of cold air spin around columns of even colder air—picture an atmospheric whirlpool six hundred miles across—and it’s possible that one of these vortices, known as cold-core lows, drifted south until it collided with the ridge in the jet stream and then unraveled its energy into a jet streak. Or a disturbance off the east coast of Asia born of the contrast between mild maritime air over the Sea of Japan and cold continental air blowing off the deserts of Mongolia might have been the jet streak’s energy source. From January 5 through 8, the observer at the U.S. Army Signal Corps station at Anvik in west-central Alaska recorded high northeast winds and snow, which may well have been a sign of the jet streak careening in from the Pacific. Or the band of enhanced winds might have risen out of the ghost of a storm that had burst and dissipated over Europe or central Asia days earlier and then fed its ephemeral remains into the jet.
In any case, some disturbance created a crimp, or “short wave,” in the smooth undulation of a long wave, and at the heart of this crimp a jet streak spurted forward. As long as it was over the Pacific or sailing up the west side of the North American ridge, the jet streak existed as pure potential—the tightening coils of an ineffable spring. Its potential would be released only if and when the jet streak encountered the right conditions to reinvigorate it.
A week into January, those conditions presented themselves one after another in quick succession like a run of losing poker hands. There was no reason why one bad hand had to follow another—the deck was shuffled and dealt anew each time. It was just the luck of the cards—loss after loss that finally compounded into catastrophe.
On Tuesday, January 10, the jet stream with its embedded jet streak, having crested the ridge somewhere up in the northern reaches of British Columbia or the southern reaches of the Yukon, began diving southeast into western Alberta. It was here that the flow encountered the immense irregular wall of the Rocky Mountains—the first losing hand. The mountains squeezed and deflected the current, altering its temperature and pressure. As the flow descended the eastern flank of the Canadian Rockies, the air warmed, and as it warmed it dropped the air pressure at the surface. Some disturbances, known as leeside lows because they form on the eastern or leeward side of the Rockies, spring to life in this way. But given the intensity of the storm that followed, it seems more likely that the remnants of an older disturbance had come in from the Pacific and amplified when the jet crossed the Rockies. As the upper flow crested the jagged obstacle of the mountain range and soared over the great flat expanses of the North American plains, it sent an immense vortex spinning counterclockwise all the way down to the surface. The ghost had come back to life.
Propelled by the high pressure building in behind it, the low worked its way southeast down the tapering lower half of Alberta on Tuesday, intensifying as it moved. The air was so cold that it had very limited capacity to hold moisture, so not much snow fell. That would come later, when the vortex fastened onto a stream of moist air coming up from the south. The stronger the low became, the more surface air it pulled toward the center of its vortex. You’d think that the low would eventually “fill” by pulling in enough air to raise its pressure and thus fizzle itself out. The reason this didn’t happen was because of the way the jet streak was roiling the flow six miles up. To continue with the bullet train and tunnel analogy: Air moving through the jet stream’s tunnel was forced to converge as it got sucked into the rear, or “entrance region,” of the jet streak’s bullet train; but when the air was hurtled out the nose, or “exit region,” of the train, it spread or diverged from the core of the flow like a delta at the mouth of a high-speed river of air. The diverging flow aloft acted like a pump, which evacuated the air below it. The winds converging at the surface got sucked up into the vortex of the low and then, due to the force of the jet streak, spewed out the top by the diverging upper-level winds. With a greater mass of air streaming out the top of the funnel than feeding into the bottom, the air pressure at the surface kept dropping. Meteorologists call this upper air support for a developing storm.
The chance alignment of the low and the jet streak’s exit region was the second losing hand. Not only did the jet amplify the low, but it forced it to take a steady course to the southeast. With the jet feeding and steering it, the disturbance was cranking up into a powerful and fast-moving low pressure system—a “mid-latitude cyclone” in meteorological parlance.
Sometime during the first hours of Wednesday, January 11, the advancing low crossed the U.S. border and began to cause the air pressure over northeastern Montana to fall. All that day it continued to churn southward, until by nightfall on Wednesday there was a well-defined trough of low pressure radiating out from the vicinity of Fort Keogh near Miles City, Montana, and extending north into southern Alberta and British Columbia and south to Colorado. By itself, the strengthening low would have kicked up some stiff wind on the Great Plains, blown the snow already on the ground into drifts, maybe spat out a few inches of new snow before subsiding: a typical midwinter storm; certainly nothing historic. But as it dug deeper into U.S. territory, the low uncovered a source of highly explosive fuel that boosted its power exponentially.
To the north of the low, up in central and northern Alberta, that pool of arctic air had hardly budged for a week now, and the longer it stagnated the colder it got. To the south, a mass of unseasonably mild and humid air from the Gulf of Mexico was beginning to stream up over Texas and Oklahoma. The potential energy in the temperature differential between these two sharply contrasting air masses was enormous. In order for that potential energy to be converted into the kinetic energy of violent weather, so
mething had to bring the air masses together—the more sudden their encounter, the more violent the weather would be. That something was the intensifying low. The fact that the low happened to wander down between these two air masses at this particular moment in time was the third bad hand. The hand that finally and abruptly ended the game.
CHAPTER FOUR
Indications
The person charged with the job of predicting the origin and movements of this spiraling atmospheric disturbance was a thirty-nine-year-old career officer by the name of Thomas Mayhew Woodruff, first lieutenant, Fifth Infantry, United States Army. Woodruff was a good man, well educated, gently born, unfailingly courteous, who took his work seriously and did his duty conscientiously. The fact that so many people died when the potential energy of this disturbance was released over the Dakotas, Nebraska, Minnesota, and Iowa on the afternoon of January 12 was by no means Woodruff ’s fault. Given the state of the art of weather forecasting in 1888, Lieutenant Woodruff did the best he could. He simply didn’t know enough to do any better—and he didn’t have the means to make effective use of what knowledge he had. It’s questionable whether anyone in 1888 could have done more.
Lieutenant Woodruff’s failure, if one can speak of human failure in the face of a storm of this force and scale, is that he lacked imagination. A common failing in a person trained and drilled all his adult life in military discipline. A common failing in an age hell-bent on material progress and territorial expansion.
A common failing in any age, perhaps.
It was nearly midnight on Wednesday, January 11, before Lieutenant Woodruff reached a decision about the indications, the term then in use for the weather forecast, and was satisfied to make it final. He knew that once he handed the slip of tissue paper to his assistant, Sergeant Alexander McAdie, there was no going back. Lives and fortunes depended on his choices, but as a soldier who had fought in the quicksilver skirmishes of the frontier, Woodruff was well accustomed to that. He picked up his pen, filled it with black ink, and scrawled out the forecast for the following day in his nervous, slanting, but perfectly legible cursive:
January 12, 12:15 AM—Signal Office War Department, Saint Paul.
Indications for 24 hours commencing at 7 AM today. For Saint Paul, Minneapolis and vicinity: Warmer weather with snow, fresh southerly winds becoming variable. For Minnesota: Warmer with snow fresh to high southerly winds becoming variable. For Dakota: Snow, warmer, followed in the western portion by colder weather, fresh to high winds generally becoming northerly. The snow will drift heavily in Minnesota and Dakota during the day and tonight; the winds will generally shift to high colder northerly during the afternoon and night.
Woodruff had decided not to issue a cold wave warning. Instructions from Acting Chief Signal Officer Brigadier General Adolphus W. Greely were extremely clear in this regard. “The exact meaning of the term ‘cold wave,’” Greely had written, “implies that the temperature will fall below forty-five (45) degrees, and that in twenty-four hours an abnormal fall of fifteen, or more, degrees will occur.” Woodruff himself was something of an expert on cold waves, having written a pamphlet on the subject back in 1885, shortly after he had been detailed for Signal Corps duty. As he well knew, the overwhelming majority of cold waves that hit the Upper Midwest originated east of the Rockies and swept east or southeast down from Montana. Temperatures would plunge first in Helena, then Bismarck and Deadwood in the western reaches of Dakota Territory, then Huron and Yankton in southern Dakota and so on until the cold air reached his own forecast office in Saint Paul. But after studying the 10 P.M. (Eastern time) observations telegraphed from Signal Corps stations to the west, Woodruff concluded that a cold wave warning was not warranted for the next day. Caution was called for, not alarm, especially given how tenuous his position in Saint Paul was. Greely himself had sent Woodruff west to open the office in Saint Paul as part of an experiment in decentralizing the government weather service. Though he had only been forecasting from Saint Paul since October, already Woodruff had issued many more cold wave warnings than his counterparts at the Signal Corps headquarters in Washington had issued the previous year. Better not to cry wolf.
At a few minutes before midnight of January 11, 1888, Woodruff handed the slip of tissue paper with the indications for the twelfth to Sergeant McAdie and instructed him to encode the message and then transmit it by telegraph to the Saint Paul Western Union office, from which it would be distributed to the Office of the Chief Signal Officer in Washington; to the Saint Paul District Telegraph Company; to the Associated Press and the major newspapers in Minneapolis and Saint Paul; to the Signal Corps observers in Milwaukee, Bismarck, Rapid City, and Fort Custer; and to Private Brandenburg of the Minnesota State Weather Service, who would see that it was distributed to sixty-seven volunteer observers in Minnesota and the Dakotas. This was the routine routing procedure for the midnight indications.
Entrusting an officer at a branch office with the task of forecasting the weather was, as both Woodruff and Greely well knew, a bold and radical move. Since 1870, when the Army’s Signal Corps first took charge of the nation’s weather, all forecasting for the United States had been done by a select handful of “indications officers” working at the Signal Office on G Street near the War Department in Washington, D.C. No matter whether it was a nor’easter bearing down on the New England coast or a persistent series of squalls threatening to flood the Mississippi, all forecasts—initially called “probabilities,” then altered to “indications” in 1876—were made in the same circuitous way: Observations were telegraphed to Washington headquarters, maps were drawn and predictions made by the small team of civilian and military meteorologists (most of them commissioned line officers with a few months’ training in physics, math, and telegraphy), and the forecasts were then telegraphed back to the field stations as well as to newspapers and railroads. But in the autumn of 1887, under pressure from a group of Saint Paul businessmen worried about the economic consequences of yet another severe winter, Greely agreed to break with Signal Corps tradition and open a branch office in Saint Paul. As Greely wrote later, “The great advantages of knowing sixteen to twenty-four hours in advance that the temperature will fall quickly, apply not only to manifold business interests, but affect the comfort of thousands, and at times the health and life of hundreds.” By Greely’s estimate, an indications officer in Saint Paul would be able to issue cold wave warnings “from two to five hours” earlier than was possible from Washington.
Assigning the post to Thomas Woodruff was an interesting if somewhat risky move on Greely’s part, riskier than the general realized at the time. A handsome well-groomed man with close-cropped fair hair parted in the middle, a bristling Teddy Roosevelt mustache, and a fine prominent nose, Woodruff was a military type more common in the late nineteenth century than in the early twenty-first—an officer and a gentleman. The fact that he was also a weather forecaster was less a matter of personal inclination or talent than a quirk of government bureaucracy and circumstance. Since the Signal Corps suffered from a chronic shortage of officers capable of or interested in observing and predicting the weather, General William B. Hazen, Greely’s predecessor as chief signal officer, had started tapping officers from other branches of the Army for Signal duty, generally detailing lieutenants from the artillery, infantry, and cavalry. Relieved temporarily of their other military responsibilities, the lieutenants were dispatched to Fort Myer (near the capital on a site adjoining Arlington National Cemetery in Virginia) for a training course in signaling, electricity, telegraphy, and the basics of physics, math, and meteorology. They were issued sabers and taught to ride horses. They learned how to send messages at all hours and in all weather by flag and torch. They were shouted at and addressed as “fish.” They took apart telegraph transmitters to see what made the “click” and put them back together. They were supposed to master the craft of tapping out Morse code. Six months later they emerged as Signal officers. Those select few who showed particula
r aptitude for the vagaries of forecasting became indications officers.
This was the path that Thomas Woodruff followed starting on February 6, 1883, when General Hazen ordered him to leave his regiment at Fort Keogh on the dry plains of eastern Montana and report to Washington, D.C., for Signal duty.
By this point, Woodruff already had over a decade of strenuous military service under his belt. Like his father before him, he had attended West Point, where he was nicknamed Tim (nicknaming entering plebes is an old West Point tradition) and graduated fifteenth in a class of forty. Immediately after graduation, he signed up with the Fifth Infantry and traveled out to Fort Wallace, Kansas, to join his company. Though he had grown up in Buffalo, New York, and Washington, D.C., with all the comforts and privileges of old Yankee families, the young Thomas Woodruff took to the West at once. For most of his twenties he was on frontier duty fighting “hostile Indians” in Kansas, Montana, and Dakota Territory. In 1876 and again in 1877, Woodruff requested permission to leave safe surveying posts with the Corps of Engineers so he could fight under Colonel (later General) Nelson Appleton Miles in his ruthless campaigns against the remnants of the once great tribes of the Plains—the Cheyenne, the Sioux, the Kiowa, and the Comanche. Woodruff was continually in the field during the autumn of 1877 when Colonel Miles pursued Chief Joseph and his band of Nez Perce holdouts for fourteen hundred miles across Montana. He fought in the five-day skirmish that ended in the capture of the heroic chief (“The Red Napoleon,” as the press called him) on October 5, 1877, and he was present when Chief Joseph spoke his famous words of surrender to General Miles: “I am tired of talk that comes to nothing…. You might as well expect the rivers to run backwards as that any man who was born a free man should be contented when penned up and denied liberty to go where he pleases.”