Cloudburst

“ The sky was laid bare, as the tidal wave empties the shore of its water before it heaps it up upon it. A violent storm of wind and rain the next day followed this delusive brightness. So the weather, like human nature, may be suspiciously transparent. A saintly day may undo you. A few clouds do not mean rain; but when there are absolutely none, when even the haze and filmy vapors are suppressed or held back, then beware.
Then the weather-wise know there are two kinds of clouds, rain-clouds and wind-clouds, and that the latter are always the most portentous. In summer they are black as night ”

“ When, after imprisonment and long sustention in a powerful tornadic vortex, the accumulated rain or hail finally breaks through and pours down to earth, in solid cataract, the phenomenon is commonly called a cloud-burst. ”

“ A blast, as if from the mouth of a furnace, greets the burning cheek; no blessed drops descend; the sky is clear as a mirror, without a single cloud to mitigate the intensity of the sun's withering rays. At last, on some happy morning, small clouds are seen on the horizon. They may be no bigger than a man's hand, but they are blessed harbingers of rain. To those who know not what is coming, there seems at first no improvement on the previous sultry calms. There is a sense of suffocating heat in the atmosphere; a thin haze creeps over the sky, but it scarcely affects the broad glare of the sun. ”

“ The cloud-burst on Mount Helena had caused many breaks in the enormous ditches that run around the mountain and carry water to the mines on the other side. No one can have the faintest conception of how terrible a cloud-burst is until they have been in one. It is like standing under an immense waterfall. At the very beginning we noticed the wagon of a countryman across the street with one horse hitched to it. The horse was tied so the water from an eaves trough poured directly upon his back, and not liking that, he stepped forward, which brought the powerful stream straight to the wagon. ”

“ Thunderstorm; pitch dark, with no blackness,—but deep, high, filthiness of lurid, yet not sublimely lurid, smoke-cloud; dense manufacturing mist; fearful squalls of shivery wind, making Mr. Severn's sail quiver like a man in a fever fit—all about four, afternoon—but only two or three claps of thunder, and feeble, though near, flashes. I never saw such a dirty, weak, foul storm. It cleared suddenly, after raining all afternoon, at half-past eight to nine, into pure, natural weather,—low rain-clouds on quite clear, green, wet hills. ”

“ When a moist wind blows in clear weather over a cold summit, it has not time to get chilled as it approaches the rock, and therefore the air remains clear, and the sky bright on the windward side; but under the lee of the peak, there is partly a back eddy, and partly still air; and in that lull and eddy the wind gets time to be chilled by the rock, and the cloud appears, as a boiling mass of white vapor, rising continually with the return current to the upper edge of the mountain, where it is caught by the straight wind and partly torn, partly melted away in broken fragments. ”

“ When clouds are seen surrounding the face of the sun, the less the light they leave, the more violent the tempest will be: but if they form a double circle round the sun, the storm will be a dreadful one. If this takes place at sunrise or sunset, and the clouds assume a red hue, the approach of a most violent storm is announced: and if the clouds hang over the face of the sun without surrounding it, they presage wind from the quarter from which they are drifting, and rain as well, if they come from the south. ”

“ In fine weather the sky was either blue or clear in its light; the clouds, either white or golden, adding to, not abating, the luster of the sky. In wet weather, there were two different species of clouds,—those of beneficent rain, which for distinction's sake I will call the non-electric rain-cloud, and those of storm, usually charged highly with electricity. The beneficent rain-cloud was indeed often extremely dull and gray for days together, but gracious nevertheless, felt to be doing good, and often to be delightful after drought ”

“ When the fog leaves the mountains, reaching upward, as if afraid of being left behind, the fair weather is near.
Shoddy clouds are of little account, and soon fall to pieces. Have your clouds show a good strong fibre, and have them lined,—not with silver, but with other clouds of a finer texture,—and have them wadded. It wants two or three thicknesses to get up a good rain. Especially, unless you have that cloud-mother, that dim, filmy, nebulous mass that has its root in the higher regions of the air, and is the source and backing of all storms, your rain will be light indeed. ”

“ Again, since rain and cloud are checks upon such systems, we should expect the sandstorm systems to be larger and far loftier than thunderstorms, and to consist of far more violent atmospheric movements. This also is the case, and when we know that some of these disturbances have the dimensions of a cyclonic storm, it is easy to understand how the finest dust may be raised to vast altitudes, into the great upper currents of the air, by which it may be borne hundreds of miles before returning to the ground. ”

“ For the sky is covered with gray cloud;—not rain-cloud, but a dry black veil, which no ray of sunshine can pierce; partly diffused in mist, feeble mist, enough to make distant objects unintelligible, yet without any substance, or wreathing, or color of its own. And everywhere the leaves of the trees are shaking fitfully, as they do before a thunder-storm ”

“ Gradually, as the densest portion of the storm cloud reaches us, it darkens; the scud are nearer the earth, and run with more rapidity; the rain falls more heavily and continuously, and by the middle of the day a thick fog has enveloped the earth; the wind is [Pg 109] dying away, and the trade itself, with its southern tendency to fog, has settled near us; the barometer has fallen, the thermometer is up to fifty degrees, the water is running down the hills, the snow is saturated with water and is disappearing under the influence of the fog, the rain, and the warm air. Evening comes ”

“ A cloud-burst may change the whole face of the mountain. Cloud-bursts come usually in the hottest weather and almost with the suddenness of an explosion. A swiftly moving black cloud tipped with fiery streaks and growing rapidly appears above the crest of the mountains. ”

“ On what anvils and wheels is the vapor pointed, twisted, hammered, whirled, as the potter's clay? By what hands is the incense of the sea built up into domes of marble?"
[9] The opposed conditions of the higher and lower orders of cloud, with the balanced intermediate one, are beautifully seen on mountain summits of rock or earth. On snowy ones [37] they are far more complex: but on rock summits there are three distinct forms of attached cloud in serene weather ”

“ But the general division which I have instituted between bad-weather and fair-weather clouds must be more carefully carried out in the sub-species, before we can reason of it farther: and before we begin talk either of the sub-genera and sub-species, or super-genera and super-species of cloud, perhaps we had better define what every cloud is, and must be, to begin with.
Every cloud that can be, is thus primarily definable: "Visible vapor of water floating at a certain height in the air." ”

“ We next come to a variety which is anything but a harbinger of good, namely, the long stripes or bands of cirrus which stretch outwards from the margin of the cloud canopy of a cyclonic storm. In some ways these appendages to the great nimbus resemble the strips of cirriform cloud which fringe the summit of a thunder-cloud. They look as if they must have been formed by the blowing away, by a rapid wind, of the top of an uprising column of vapour-charged air. ”

“ Behind it, westward and seaward, all's clear; but when the wind out of that blue clearness comes over the ridge of the earth-cloud, at that moment and that line, its own moisture congeals into these white—I believe, ice-clouds; threads, and meshes, and tresses, and tapestries, flying, failing, melting, reappearing; spinning and unspinning themselves, coiling and uncoiling, winding and unwinding, faster than eye or thought can follow: and through all their dazzling maze of frosty filaments shines a painted window in palpitation ”

“ On the other hand, a torrential shower may fall for a few minutes from a tropical cumulus cloud—shallow as to extent and without the angry-appearing cauliflower head of the ordinary cumulo-nimbus.
The fibrous mantle that hovers over the top of the cumulo-nimbus is a cloud of snow flakes. The cloud itself is usually, but not always, a thunder-storm. The observer may disregard all theoretical matters and record it as a cumulo-nimbus if rain is falling from its base. ”

“ A thin cloud sweeps over the white ground—it is formed of whirling snow; the wind becomes a tempest; the cloud rises up to heaven: and, maddening, bewildering even to the most weather-hardened, dangerous in the extreme to all things living, the buran rages across the steppes, a snow-hurricane, as terrible as the typhoon or the simoom with its poisonous breath. For two or three days such a snow-storm may rage with uninterrupted fury, and both man and beast are absolutely storm-stayed. A man overtaken in the open country is lost, unless some special providence save him ”

“ The deposit of spray from the spout of a teakettle might, without much stretching of terms, be described as a miniature artificial rainstorm; but much bigger showers, in nowise different from those occurring in nature, can also be produced artificially. Huge clouds have often been observed to form over forest fires and other great conflagrations. These clouds, composed of water drops, tower far above the smoke cloud, and are identical in character and mode of origin with the cumulus and cumulo-nimbus clouds formed by currents of moist air rising from the heated ground on a summer day. ”

“ Quarter to eight, morning.—Thunder returned, all the air collapsed into one black fog, the hills invisible, and scarcely visible the opposite shore; heavy rain in short fits, and frequent, though less formidable, flashes, and shorter thunder. While I have written this sentence the cloud has again dissolved itself, like a nasty solution in a bottle, with miraculous and unnatural rapidity, and the hills are in sight again ”

“ It rapidly approaches nearer and nearer, the clouds touching the lower hills, then down darts the forked lightning, followed by the roar of the thunder, and presently a wild rush of wind, as if it came from all quarters at once, tells us that the storm is upon us, and then comes the rain, in big heavy drops for a few seconds and soon in torrents, as if the sluice-gates of the clouds were opened. ”

“ These clouds precede wind and rain. The near or distant approach of a storm may often be judged of from their greater or less abundance and duration. They are almost always to be seen in the p. 91intervals of storms. Sometimes the cirro-stratus, and the cirro-cumulus, appear together in the sky, and even alternate with each other in the same cloud, presenting many curious changes; and a judgment may be formed of the weather likely to ensue, by observing which prevails at last. ”

“ Modern science has shown the tracks of the storms and partially explains the reasons for this dry and barren nature of this region. When rains do come they are so out of the regular order, that they are called cloud-bursts or waterspouts, and the washes in the cañons and their mouths show how great has been the volume of water that sometimes rushed down the slope. If clouds at a warm or moderate temperature float against these snow peaks all the water they contain is suddenly precipitated. ”

“ Even thunder-showers are wrested by some men into a political significance!
The circumstances of the case, however, would appear to have been these: A dense cloud, borne upon a low southwest surface-current of wind, was passing across the deep valley of the West River, half a mile or so from its mouth, when it was probably struck by a cool, dry mountain-breeze flowing down the valley. This breeze imparted new electricity to the cloud, which, being thus overcharged, gave out its surplus in a sudden shock, which took effect upon, a group of pines. ”

“ After twenty years Argus water rose in the wash against the frail houses, and the piled snows of Kearsarge slid down at a thunder peal over the cabins and the camp, but you could conceive that it was the fault of neither the water nor the snow.
The first effect of cloud study is a sense of presence and intention in storm processes.
Weather does not happen. It is the visible manifestation of the Spirit moving itself in the void. It gathers itself together under the heavens ”

“ I have defined the floating or sky cloud, and defined the falling, or earth cloud. But there's a sort of thing between the two, which needs a third definition: namely, Mist. In the 22d page of his 'Glaciers of [10] the Alps,' Professor Tyndall says that "the marvelous blueness of the sky in the earlier part of the day indicated that the air was charged, almost to saturation, with transparent aqueous vapor." Well, in certain weather that is true. You all know the peculiar clearness which precedes rain,—when the distant hills are looking nigh. ”

“ Only artificial, and very high illumination would give the real effect of them,—painting cannot.
Enough, however, is here done to fix in your minds the distinction between those two species of cloud,—one, either stationary, [16] or slow in motion, reflecting unresolved light; the other, fast-flying, and transmitting resolved light. What difference is there in the nature of the atoms, between those two kinds of clouds? I leave the question with you for to-day, merely hinting to you my suspicion that the prismatic cloud is of finely-comminuted water, or ice, [17] instead of aqueous vapor ”