Mission Plan :

NOAA 49RF will fly a Synoptic Surveillance Mission around Tropical Storm Dolly. 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 32 GPS dropsonde points.

Fig. 1: Flight track (blue line) for Synoptic Surveillance mission 20080831N1. The GPS dropsonde points (32 total) are indicated by numbered circles.

Synoptic Surveillance
MISSION PLAN
DOLLY
July 21, 2008 12:16:40 PM

Aircraft: N49RF Altitude: FL410-450 Proposed takeoff: 22/0530Z
DROP #	LAT (d m)	LON (d m)	TIME (h:mm)
1	28 00	-87 00	0:34
2	27 00	-88 00	0:46
3	26 00	-89 00	0:57
4	25 30	-87 00	1:13
5	24 00	-87 00	1:25
6	23 00	-86 00	1:37
7	22 00	-87 00	1:48
8	23 00	-88 00	1:59
9	24 00	-89 00	2:11
10	25 30	-91 06	2:31
11	24 12	-90 48	2:42
12	22 54	-91 06	2:53
13	21 51	-91 56	3:04
14	20 00	-91 00	3:21
15	19 00	-92 00	3:32
16	18 24	-94 06	3:49
17	21 17	-93 08	4:14
18	21 17	-94 28	4:25
19	21 51	-95 40	4:35
20	21 00	-97 00	4:48
21	22 54	-96 30	5:04
22	24 12	-96 48	5:15
23	26 33	-95 40	5:36
24	28 57	-94 58	5:56
25	27 07	-94 28	6:12
26	27 07	-93 08	6:22
27	26 33	-91 56	6:32
28	28 00	-92 00	6:44
29	29 00	-91 00	6:55
30	28 00	-90 00	7:07
31	30 00	-88 00	7:29
32	29 00	-85 00	7:53

Mission Summary :

a) Synoptic Situation
Tropical Storm Dolly was located in the western Gulf of Mexico and postioned approximately due south of a deep layer ridge (centered over eastern Texas/western Louisiana). Upper-level outflow was quite impressive around the western and northern semi-circles of the storm, but was being impeded on the east and southeast sides by an upper-level low located over the Bay of Campeche. Not surpisigly, GOES IR imagery indicated that convection was concentrated around the western and northern semi-circles and somewhat stifled on the east and southeast sides of the storm.

b) Mission Specifics
Takeoff was at 0537 UTC from MacDill. After the first few dropsondes were successfully transmitted off the plane, transmissions of the TEMPDROP messages began repeatedly failing. The HRD dropsonde scientist worked closely with the G-IV data system specialist to determine the cause of the data transmission failures and unsuccessfully attempted to use a backup data transmission method to send the TEMPDROPS messages off the plane. A last resort method of emailing each individual TEMPDROP message directly to NCEP did work successfully and was used to send off the remaining 25-30 TEMPDROP messages from the aircraft.

GPS dropsonde data from 200 hPa clearly indicated Dolly's strong outflow to the north and restricted outflow to the south and southeast. Dropsonde data from 150-300 hPa also suggested that the strong inflow to the north of the storm was relatively shallow and restricted mainly to a layer from 200-250 hPa. Additionally, dropsonde data of 500 hPa winds and heights indicated the presence of the deep layer ridge north of Dolly that was also clearly stretched into the northeast Gulf of Mexico behind the storm.

Moderate clear air turbulence was encountered from drop points #15-32 and was a result of the aircraft flying through 35-55 kt winds associated with Dolly's upper-level outflow.

Problems :

The real-time transmission of GPS dropsonde TEMPDROP messages was particularly challenging during this mission. The backup method of emailing individual TEMPDROPS messages directly to NCEP was successful, though quite time consuming. Surprisingly, several of the new UBLOX dropsondes failed during the mission: 2 dropsondes had no launch detect, 2 dropsondes were fastfalls, and 2 dropsondes had no winds. Of the 36 dropsondes launched during the mission, 32 were successfully transmitted off the plane.