5 October Start/Stop Times

Flight 1

Start Stop Maneuver

18:13:53 18:22:24 A to B; Descent 7K’ to 500’

18:22:24 18:42:30 B to C; 500’

18:43:03 18:56:52 C to E’; 500’

18:58:46 19:12:30 E’ to C; 1.5K’

19:13:22 19:24:21 C to E’; 1K’

19:26:38 19:35:11 E’ to C; 3K’

19:35:11 19:38:05 C; Ascent to 7K’

19:38:05 19:47:37 C; Descent to 500’

19:47:37 19:55:14 C to F’, 500’

19:56:11 19:56:40 F’ to G’; 500’ (End of 1^st file)

19:58:15 20:07:30 F’ to G’; 500’ (2^nd file)

20:09:00 20:17:21 F’ to G’; 500’ (3^rd file)

20:18:13 20:23:48 G’ to C; 500’

20:24:11 20:47:46 C to D; 500’

Flight 2

Start Stop Maneuver

23:14:14 23:38:31 D’ to C; Porpoise 300’ to 2K’

23:39:09 23:52:43 C to E’; 500’

23:54:01 00:07:22 E’ to C; 1.5K’

00:08:45 00:20:06 C to E’, 1K’

00:21:19 00:31:30 E’ to C, 3K’

00:31:30 00:34:04 C; Ascent to 7K’

00:34:04 00:43:29 C; Descent 7K’ to 500’

00:43:29 00:48:25 Return to C

00:48:25 01:16:53 C to B’; Porpoise 300’ to 2K’

01:16:53 01:25:17 B’ to A, Ascent to 7K’

Initial Impressions: This pair of flights sampled the terrain effects in the Fairweather Grounds as the large-scale background flow underwent a significant transition in association with a landfalling front and a developing secondary low to the south of the operating area. In particular, the winds near B changed from about 165 at 35 knots near the start of the first flight to about 100 at 15 knots near the end of the second flight. The overall environment was much more convective during the second flight (although the static stability below 2-3K’ does not look that much different, at first glance). Interestingly, during the evolution of the background flow, the winds near C did not change much. The first flight found 500’ winds from about 145 at 40-45 knots, while the second flight recorded 500’ winds from about 135 at 40 knots. There was a similar enhancement of the speeds near the coast of 10-15 knots versus farther offshore. The horizontal shear appears to have been more localized and closer to the beach on the first flight. This windshift seemed to be accompanied by a rather persistent rainband. On the second flight the precipitation was much more cellular. The top few thousand feet of the descent near C on the second flight was in one of these cells and hence represents a sample of lifted boundary layer air rather than the ambient conditions. This case represents a potentially important example of how barrier effects vary under different background conditions, but it may end up being difficult to separate out all the contributing factors.