7 October Start/Stop Times

Start Stop Maneuver

00:09:40 00:31:09 A; Descent from 7K’ to 500’

00:31:49 00:41:00 A to B’; 500’

00:41:20 00:51:54 B’ to C’; 500’

00:53:33 01:06:00 C’ to B’; Porpoise 300’ to 2K’ (once to 3K’)

01:06:34 01:24:07 B’ to F2; Porpoise 300’ to 2K’

01:25:18 01:49:52 F2 to A; Porpoise 300’ to 2K’

01:50:29 02:00:30 A to B’; Porpoise 300’ to 2K’

02:00:30 02:13:47 B’ to C’’; Porpoise 300 to 2K’

02:14:37 02:18:30 C’’ towards F2; 500’

02:18:30 02:27:43 Near C’’; Ascent to 12K’

Initial Impressions: This flight consisted of a survey of easterly (offshore flow) in the vicinity of the mouth of Cross Sound. This easterly flow was associated with a deep (~970 mb) low to the south of the study region. The situation was less one of classic gap flow and more one of relatively deep easterly flow that was partially blocked by the moderate terrain south of Cross Sound and completely blocked by the high terrain north of Cross Sound (the Fairweathers). The strongest low-level (500’) flow out of Cross Sound was from 60 deg. at about 29 knots and was about 10 km SE of point B. The winds first slackened some heading NW from this point along the coast and then picked up again to about 33 knots before dropping off very suddenly (to just a few knots from variable directions including out of the northwest) over a distance of a few km. The turbulence was quite light in this zone of high anti-cyclonic shear (~ -50f).The aircraft hence confirmed the intense shear indicated in the SAR overpass 2 hours later. This shear zone was sampled three other times: heading back towards B’ between the 1K’ and 2 K’ levels while porpoising, between about 600’ and 1K’ levels between B’ and C, and at the 500’ level somewhat farther from the coast (the latter roughly 1/2 hour before the overpass). A triangle between B’, F2 and A was executed while porpoising to assess the offshore structure of the easterly flow. There was a slow drop-off winds from B to F2 in an overall sense (less so near the surface) and a more pronounced decline towards A. This is liable to represent a good case to contrast against more classic gap flow due to interior high pressure, and presumably, shallower offshore-directed flow more restricted to the channels in the terrain.