Aircraft Commander | Michele Finn |
Pilots | Will Odell
Gregg Glover |
Flight Director | Paul Flaherty |
AVAPS | Jim Roles Jorge Delgado |
Data System | Chuck Rasco |
Dropsonde Scientists | Jason Dunion John Kaplan |
Mission Plan :
NOAA 49RF will fly a Synoptic Surveillance Mission around Hurricane Gustav. The G-IV will leave MacDill AFB at 0530 UTC and recover at MacDill at 1330 UTC.The flight track will take the G-IV on a clockwise circumnavigation of the TC and is shown in Fig. 1, along with the 29 GPS dropsonde points.
Aircraft: N49RF Altitude: FL410-450 Proposed takeoff: 31/0530Z | |||
DROP # | LAT (d m) | LON (d m) | TIME (h mm) |
1 | 28 00 | -79 00 | 0:27 |
2 | 28 00 | -77 00 | 0:42 |
3 | 26 00 | -76 00 | 1:01 |
4 | 26 00 | -78 00 | 1:16 |
5 | 25 36 | -83 00 | 1:55 |
6 | 23 26 | -83 01 | 2:13 |
7 | 21 14 | -83 48 | 2:32 |
8 | 21 23 | -85 02 | 2:42 |
9 | 21 23 | -86 22 | 2:52 |
10 | 21 57 | -87 34 | 3:03 |
11 | 23 00 | -88 24 | 3:14 |
12 | 22 00 | -89 30 | 3:25 |
13 | 22 00 | -91 30 | 3:41 |
14 | 24 00 | -92 30 | 3:59 |
15 | 24 00 | -90 30 | 4:15 |
16 | 24 18 | -88 42 | 4:29 |
17 | 25 36 | -88 24 | 4:40 |
18 | 26 00 | -90 30 | 4:57 |
19 | 26 00 | -92 30 | 5:12 |
20 | 26 00 | -94 30 | 5:28 |
21 | 28 00 | -93 30 | 5:46 |
22 | 28 00 | -91 30 | 6:01 |
23 | 28 00 | -89 30 | 6:17 |
24 | 28 00 | -87 30 | 6:32 |
25 | 26 39 | -87 34 | 6:43 |
26 | 27 13 | -86 22 | 6:54 |
27 | 28 30 | -84 30 | 7:11 |
28 | 27 13 | -85 02 | 7:22 |
29 | 26 39 | -83 50 | 7:33 |
Mission Summary :
a) Synoptic Situation
Hurricane Gustav was just emerging from the western side of Cuba into the
Gulf of Mexico at the time of take off. The storm was positioned along the
western periphery of a deep layer ridge to the northeast and was tracking at
320 deg at 13 kt. Upper-level outflow was quite well developed around the
northern semi-circle of the storm, but GOES water vapor imagery indicated that
although this was a major hurricane, most of its southern semicircle was being
impacted by upper level inflow.
b) Mission Specifics
Takeoff was at 0621UTC from MacDill (delayed due to data comm issues with some
of the scientific computers on the aircraft). Since the G-IV got off to a
late start, there was concern that some of the data toward the end of the
mission would miss the cutoff time for being assimilated into the 12 UTC GFS.
Since this equates to ~10:30 AM EDT, it was decided that drop #2 and 3 would
be skipped and the mission would proceed directly to drop/turn #4 after
drop/turn #1.
GPS dropsonde data from 200 hPa confirmed that although the outflow was quite impressive around the northern semicircle (40-60 kt), there was 25-35 kt upper-level inflow impinging on the storm to the south. Moderate turbulence was encountered from drop point # 23 to 29 in association with Dolly's strong upper-level outflow on the north side of the storm. Problems :
There appeared to be an abnormal number of dropsonde failures during this mission: 4 dropsondes had no launch detect, 1 dropsonde had a very late launch detect, and 1 dropsonde had no winds. Additionally, the AVAPS system went down for a brief period at drop point #24 (28.0⪚N 87.5°W) and that dropsonde was lost. Of the 33 dropsondes launched during the mission, 26 were successfully transmitted off the plane. AOC later reported to HRD that there was a concern that newly acquired dropsondes with the 2nd generation GPS module may be defective and may explain why there where so many failed UBLOX dropsondes during this G-IV mission.
Mission Data :