DC-8 Flight Summary: 24 August 1998


Takeoff 193904 UTC/24 Aug Landing 032758 UTC/25 Aug


Mission objectives:

1. Execute two "figure-four" patterns through the center of Hurricane Bonnie, coordinated between DC-8 and ER-2, and (more or less) with two NOAA WP-3D's as well. Result is 8 radial legs to about 100 nm distance from storm, spaced 45 · apart. In addition, in an attempt to get data from LASE and MACAWS, the second figure-four has legs extended to 140 nm radius.

2. After the last pass through the storm, execute a long leg under the anvil on the west side of the storm to a position close to Andros Island, then fly a data leg just east of Andros site on the return to Patrick.



Mission flown as planned. All pre-briefed points had to be shifted to the ENE by about 30 nm due to updated storm center fixes. The ER-2 lost their nav
computer, so we had to be judicious in passing new way points to them, but thanks to the good work of our Navs and the ER-2 pilot the mission was saved.

Wind and cloud structure in Bonnie on this day was very interesting. While remnants of an inner eye were occasionally visible, including a report of a big buildup, the large radius eyewall was more prominent, at least at our altitude. As on the previous day, strongest winds tended to be in the quadrants away from the convection. There were west and northwest winds dominating the western semicircle right into the center, while a major divergent source region was on the east side. This source region apparently was responsible for the huge cirrus shield extending even to 140 nm west of the center, with falling "snow" at our altitude in spite of strong west (!) winds. On entry from the west, at about 2306 UTC, the large-scale eye was manifestly visible in a swirling pattern in the low clouds, but this feature was about 30 nm NW of the eye position as reported by NOAA and the wind eye at our altitude.

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