Flight: 2004_01_30a
On board: Kevin, Bart, Dave, Larry
Take-off: 12:57 UTC - Landing: 16:34 UTC - total duration 3 hrs 37 min
Author: Bart

1. Synopsis:

The surface temperatures in Racine and Sheboygan at take-off are about -23C 
to -24C. This is colder than any other flight so far. The entire region of 
flight remains cloud-free at all levels above the CBL. Surface winds at 
Racine from the NW (310-320) at 10 kts. Large sheets of new ice, not broken 
by waves, cover the first few km from shore, and pancake ice floes drift 
further offshore, with perhaps 90% ice and 10% water. As soon as we reach 
open water some 10 km offshore, clouds occur.  Streamers of steam fog are 
seen everywhere, but mainly between the ice floes near the upwind shore. 
Some ice piles up near Muskegon but it remains east of our easternmost point 
on the flight.

During the flight the winds are 10-12 m/s at all levels (more like 10 m/s 
above the CBL and 12 m/s within); directions vary between 305 (above the CBL) 
and 325 (low levels). The Green Bay sounding suggests stable conditions up to 
700 mb, and generally a NW flow. Well-developed cumuliform clouds are visible, 
everywhere. Clear breaks are found only towards the west: near the eastern 
shore cloudiness is pervasive. That is confirmed by the GRR WSR-88D radar. 
The latter suggests that these cumuli are marginally aligned in streets 
oriented about 315-135. Bob Kelly, looking at GRR WSR-88D animations, notes 
that sometimes lines are visible, sometimes not; the dominant mode is cellular,
closely-spaced cells with thin, barely resolvable breaks in between. Never 
any clearly defined echo lines with clear break lines in between though, as
we observed on 1/22. Near the western cloud edge, some cloud lines oriented 
300 spacing about 500 m.

2. Instruments

No problems that I am aware of. Dave encountered two VXI problems upon 
switching mode (one at 15:36), resulting in very little data loss. Start
of radar operations was delayed a bit, presumably because the radar was quite
cold. Apparently the systems wants to auto-shut down.

3. Flight tracks: a 320 track roughly along the A section (endpoints are
SW=42 deg 45'N and 86 deg 43'W; NE=43 deg 00'N and 86 deg 20'N). This track
was flown 15 times, as follows:

- Racine to 320B: to 5000 ft MSL,
- 320B to 320B1: sounding down to 500 ft, U/D
- 13:26:00- 13:33:35: NE to SW, 5500 ft MSL, VPDD
- 13:36:05- 13:45:00: SW to NE, 2900 ft MSL, U/D
- 13:47:18- 13:56:00: NE to SW, 3500 ft MSL, HPDD (forced by ATC up to 4000 ft at 13:49)
- 13:57:35- 14:05:20: SW to NE, 5500 ft MSL, VPDD
- 14:07:40- 14:17:00: NE to SW, 2500 ft MSL, U/D
- 14:19:50- 14:29:00: SW to NE, 500 ft AGL, slant-side & UP (track readjusted at 14:20:40)
- 14:31:00- 14:39:10: NE to SW: ramp sounding, 280 ft AGL to 6000 ft MSL, U/D (VPDD starts at 14:36:40)
- 14:42:10- 14:50:10: SW to NE, 5300 ft MSL, VPDD
- 14:52:20- 15:00:30: NE to SW, 3000 ft MSL, HPDD
- 15:03:00- 15:11:15: SW to NE, 2500 ft MSL, U/D
- 15:14:20- 15:22:10: NE to SW, 5500 ft MSL, VPDD
- 15:25:00- 15:33:20: SW to NE, 3000 ft MSL, HPDD
- 15:36:00- 15:45:20: NE to SW, 500 ft AGL, slant-side & UP
- 15:47:30- 15:55:10: SW to NE, 2500 ft MSL, U/D
- 15:58:00- 16:06:00: NE to SW: ramp sounding, 280 ft AGL to 6000 ft MSL, U/D
- 16:06:50- radar shut-off at 16:25:00: continue on towards Racine (WCR in VPDD)
- 16:07-16:15: Rodi manoevers at 6000 ft: air seems to be very quiet