Page:Weather Facts and Predictions.djvu/32

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it is that such phenomena are to be regarded as presaging foul weather.

Cumulus of moderate height and size, with well-defined curved outlines, and visible only during the heat of the day, especially if they come up with the wind, indicate a continuance of fine weather.

But when they increase with great rapidity, sink down into the lower parts of the atmosphere, and do not disappear towards evening, rain may be looked for. If loose fleecy patches of cloud begin to be thrown out as it were from their surfaces, especially if they move against the wind, the rain is at hand.

If cumuli diminish in size towards evening, they betoken fine weather, but if they increase foul weather. Large masses of cumulus following rain often precede squalls of hail or rain.

Nimbus (rain cloud): when this is seen approaching, and cirri are noticed to be shooting out from the top in all directions, as the cirri are more numerous, so the rainfall will be more copious.

Stratus clouds forming at sunset and breaking up as the sun rises in the heavens, and soon disappearing altogether, indicate a continuance of very severe weather. When clouds are seen drifting about aloft, the air on the ground being still, or nearly so, wind is approaching, and the clouds indicate the direction from which it will come.

Clouds drifting about at sunset, from whatever quarter, betoken rough weather.

Dusky clouds, or clouds of the hue of tarnished silver are a sign of hail. If traces