Mission Plan :

N43RF is scheduled to fly an EMC-tasked Tail Doppler Radar mission into weakening Tropical Storm Tomas north of Hispañola. The plan is for a butterfly pattern with 90-nm legs, taking off from St. Croix at 0800 UTC and recovering at MacDill. To get microphysical data, after the second pass, the plan was to descend to 2500 ft for the downwind leg, rising 500 ft every 10 minutes. At the end of the downwind leg, the plan was to go to 5000 ft for the center pass, releasing dropwindsondes every minute to get turbulence data. The subsequent downwind leg was to also be a stairstep, rising 1000 ft every 10 minutes. The final pass was to be completed at 10000 feet. Because Tomas was weakening, the mission was conducted as planned, except for the rapid dropwindsonde releases on the third pass.

Mission Summary :

Figure 1. Dropwindsonde/Doppler radar composite at 0.5 km altitude from 20101106I1 flight into Tomas.

The mission was fully successful with four passes through the center and four radar analyses sent. Fifteen dropwindsondes were released at the endpoints and in the center; one was a fast fall. Also very successful was a test of getting the radar data sent directly from the aircraft to NCEP/NCO.

Figure 2: As in Fig. 1, but at 9.5 km altitude.

Tomas had been disrupted by its passage near Hispañola, but was expected to restrengthen into a hurricane sometime either during the mission or shortly thereafter. Radar composites showed that Tomas was not as asymmetric as during the previous flight. Maximum winds at 0.5 km altitude (Fig.1) were 70-80 kt, suggesting that Tomas was near hurricane strength. A front just to the northwest was expected to bring cool, dry air into the system; the strong northerly winds near the surface behind the front can ben seen in Fig. 1, and the dropwindsonde at the northwest point shows the dry air. A well defined wind center, nearly vertically stacked, extended up to at least 10 km (Fig. 2) in the Doppler composites, suggesting a lack of strong shear affecting the core. The radar analysis from the first pass alone (not shown) showed strong mid-level westerly winds beginning to encroach on the core. However, these strong winds disappeared by the last pass and are not evident on the composite analyses. The relaxation of these winds allowed for Tomas to strengthen after the mission into a hurricane.

Problems :

No major problems encountered. Scientists are to be reminded to bring their passports with them whenever we travel for the field program as we never know where we might recover.

LPS forms | Radar forms | Dropsonde forms
Serial data | 1 second data | NetCDF data | SFMR (NetCDF) data |

Flight track	Temperature and Moisture	Wind and Atlitude
Flight track

Page last updated February 22, 2011
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