When porpoises come into shallow water and ascend the river stormy weather is near.
Sea birds fly far out to sea in fine weather, but if they fly inland bad weather may be expected.
A halo round the moon, especially if it appears distant and yet very distinct, indicates a gale of wind and probably rain.
When the wind changes it usually shifts with the sun from left to right. Thus an East wind shifts to West by way of Southeast, South and Southwest, and a West wind shifts to East by way of Northwest, North and Northeast. If the wind shifts the opposite way it is said to "back," but this it rarely does except in unsettled weather.
The United States Signal Service has a local observer stationed at each of the principal ports. When the "information signal," which consists of a red pennant, is displayed, it indicates that information has been received from the central office of a storm covering a limited area, dangerous only for vessels about to sail to certain points. Ship-masters and others interested will be supplied with the necessary information on application.
A cautionary signal, which is a Yellow Flag with a white center, indicates that the winds expected are not so violent that well found and seaworthy vessels cannot encounter them without great danger. A cautionary flag hoisted alone signifies that the direction of the expected wind is doubtful.
CAUTIONARY SIGNALS.
A dangerous storm signal, which is a Red Square Flag with black center, is hoisted when the wind is over thirty-five miles an hour.
At night a Red Light indicates Easterly winds, and a Red and White Light Westerly winds.