Regional And Mesoscale Meteorology Team
Daily Satellite Discussion
Thursday October 30,1997
From the Air Force reconnaissance reports it is known that the eye wall at this time was circularly shaped and continuous. The center of the storm was located by the same Hurricane Hunter aircraft. One minute flight level(700 mb) wind observations from this reconnaissance flight are displayed in Fig. 2 which is a the same image as Fig. 1 remapped to a Mercator projection and magnified. The speed and motion of the storm have been removed from the wind observations so that the storm's center is fixed with respect to the wind barb locations over the 6-hour synoptic observation period. Note that the center of the storm is well defined by the wind field. Accepting that the center is correctly located, the bright area shown both in Fig. 1 and Fig. 2 appears to be the eastern portion of the eye wall which has a pronounced slope with height. Only this portion of the sloping eye wall is seen because of the location of the satellite (GOES-8) relative to the storm. This optical effect, or parallax, must be accounted for when examining satellite imagery. Though the example shown here is very simple, there are cases when the parallax will lead to incorrect interpretation of satellite imagery.
John Knaff