No. 1400
Price 10 cents
Founded upon the researches made in the early part of the nineteenth century by Matthew Fontaine Maury, while serving as a lieutenant in the United States Navy.
(From bottom of chart)
N. A.—NOVEMBER, 1927.
Printed October 15, 1927
Prepared from data furnished by the HYDROGRAPHIC OFFICE of the NAVY DEPARTMENT and by the WEATHER BUREAU of the DEPARTMENT OF AGRICULTURE.
[Legislative Act, June 17, 1910.]
Published at the HYDROGRAPHIC OFFICE under the authority of the SECRETARY OF THE NAVY Washington, D. C.
1 AVERAGE CONDITIONS OF WIND AND WEATHER OVER THE NORTH ATLANTIC OCEAN DURING NOVEMBER
Pressure.—Pressure continues only moderately high along middle latitudes, but the crest to the southwestward of the Azores has increased to 30.15 inches. Off the coast of the United States the isobar of 30.10 inches extends farther eastward into the ocean than in October. A belt of moderately low pressure, 29.90 inches, extends in low latitudes across the ocean into the Caribbean Sea. The Iceland Low continues to deepen and the isobar of 29.70 inches appears in the position occupied by the 29.80 line of the previous month.
Temperature.—The temperature has fallen 10° to 18° along the American coast and on the Gulf of Mexico except off central and southern Florida, and 3° to 8° over the British Isles and off western Europe. Elsewhere the changes have been unimportant. Sharp contrasts in temperature appear off the American coast, the temperature ranging from 30° in the Gulf of St. Lawrence to 75° at Key West. Along the northern trans-Atlantic routes the mean is from 45° to 55°. In the greater portion of the Caribbean Sea and east of it, between the 15th parallel and the Equator, the temperature is about 80°.
Westerly Winds.—North of the 35th parallel the winds are fresh, with greatest percentage from the westerly quadrants, although they shift considerably with the passage of cyclonic storms.
Northwesterly winds sweep the American coast from the Gulf of St. Lawrence to Hatteras. South of Hatteras they become northerly to northeasterly, merging with the trades south of Jupiter.