Chief Scientist -- J. Gamache
Doppler Scientist -- M. Black, P. Dodge
C-SCAT Scientist -- P. Black
Observers -- W-C Lee (NCAR), E. Ritchie (Penn State)
This document is divided into 3 sections (Each section is written by the Chief Scientist):
At 0039 UTC (16.82N 61.00W), N42RF and N43RF began their next coordinated "4". N42RF tracked inbound on 060, making the CPA at 0050 UTC (17.15N 60.3W). This was a good fix, and the EMSP was 940 mb. A wind maximum of 57 m/s was seen on the ENE side of the center. The next two turn points were 0100 UTC (17.5N 59.67W) and 0113 UTC (17.87W 60.82W), which straddled the downwind leg along track 285. At 0113 UTC N42RF began a penetration along track 150. The center was estimated at 0127 UTC (17.07 60.38W ). The maximum wind on the NNW and SSE sides were 62 and 52 m/s, and the EMSP was 937 mb. N42RF's participation in the second coordinated "4" ended at 0137 UTC (16.47N 59.98W). The next downwind leg took N42RF to 16.72N 59.7W at 0141 UTC. This began t he non-coordinated "4", as the N42RF tracked 300 inbound to the center, which was estimated to be at 17.15N 60.45W at 0154 UTC. The EMSP was 943 mb, and 52-53 m/s maximum winds were found on the WNW side. The endpoint was at 0205 UTC (17.48N, 61.18W) an d a downwind leg was flown to 16.52N 61.0W (0216 UTC). The last non-coordinated radial penetration was along a track of 030, reaching the CPA at 0228 UTC. The center was estimated at 17.1N 60.61W, and 65 m/s maximum was found on the NNE side. At 0238 U TC N42RF flew a downwind flight leg along track 255, reaching the next coordination point (17.5 61.16W) at 0249 UTC.
Again, no waiting time was required to coordinate with N43RF. N42RF proceeded inward along a track of 120. The CPA was at 0259 UTC and the center was estimated to be at 17.18N 60.55W. The EMSP was 938 mb. The maximum wind speeds seen on the WNW and ESE sides of the center were 59 and 53 m/s, respectively. The downwind track was from 0311 UTC (16.8N 59.85W) to 0322 UTC (17.9N 60.17W), when N42RF began its last radial penetration of Hurricane Luis along a 210 track. The maximum winds on the NNE and SSW sides were 58 and 55 m/s, respectively, and the center was estimated to be at 17.18N 60.69W at 0336 UTC. The pattern ended at 0347 UTC (16.47N 61.08W). The USAF reported a fix at 10,000 ft at 0348 UTC, to be 17.12N 60.81W). The eye of Luis was quit e large (40 nm), and thus an exact center could float around quite a bit. It did appear, however, that the eye shrank considerably while we were there, going down to about 25 nm. The consistent differences between 10,000 ft and 12,000 ft might have resu lted partially from vertical shear, and of course might also have resulted from INS errors.
N42RF landed back at Barbados at 0445 UTC. The motion during the flight appeared to be mostly westward, the eye appeared to shrink, yet the maximum flight-level winds actually decreased nearly 10 m/s during 950904H1.
There was one major glitch in the radar recording during 950904H1. The DAT drive rewound and began to record over the data earlier in the flight. Fortunately, the data beyond this rewrite were recovered (seemingly miraculously), and the only data lost during the actual pattern were along a downwind leg near 0215 UTC.
The listening to the ODW drops of N43RF again appeared to go well.