EYE REGION OF HURRICANE EDNA, 1954

Abstract

The eye region of Hurricane Edna (1954) is studied with the principal aid of radar and dropsonde data. Vertical sections show that over the eye there was a thick layer derived from the wall cloud which bounded the eye on the northeast. Precipitation fell from this upper layer into drier air beneath. A reasonable mechanism is thereby suggested by which large moisture values can become associated with air in the eye without producing the wet bulb potential temperatures or high winds characteristic of the rain-filled masses outside the eye. Radar data giving the height of the ?bright band? or melting level show that the warm core structure of Edna was most pronounced within the radius if maximum surface winds. The result is qualitatively confirmed by soundings and by comparison of surface winds and the speeds of radar weather elements in various portions of the storm. The radar photographs also show that heavy precipitation near the eye of Edna was bounded sharply in the western semicircle along an east-west line through the center of the storm. This boundary must be associated with a rather large change of vertical air speeds and therefore has special dynamic significance.