Mission Plan :

A mission as Gustav emerges from the Cuban coast moving northwestward. A figure-4 is planned with no modification for land, followed by maneuvers for Ocean Winds (NESDIS).

Mission Summary :

Takeoff: MacDill 2018 UTC Landing: MacDill 0153 UTC

NOAA42 departed MacDill slightly late due to thunderstorms in the Tampa area delaying fueling and engine start-up. At the time NOAA42 approached the core of Gustav, land-based radar (Fig. 1) showed that the eye was just making landfall on the southern coast of Cuba, and was very well defined. In addition, a recent pass by the AF reported "stadium effect", suggesting that the Gustav was a very strong and well organized storm. The figure-4 was completed when Gustav was inland over western Cuba. During the first pass,

Figure 1: Radar reflectivity from Punta del Este, Isla de la Juventud radar at 2100 UTC 30 August, as Gustav was making landfall as a category 4 hurricane, and at about the time that NOAA42 entered the core.

flight-level winds of about 136 kt were reported; because Gustav was over land, no SFMR reading was available during this time. Two radar analyses (not shown) were completed after the figure-4 pattern. Neither was particularly interesting except that the low-level wind speeds decreased about 5 m/s from the first to the second pass (after landfall). In both analyses, the cyclonic circulation extended upward well past 15 km in height. Nine dropwindsondes were released during the pattern (not shown), including a few along the south coast of Cuba between La Isla de la Juventud and mainland Cuba, in shallow bathymetry.

After the figure-4 pattern over land was completed, the aircraft turned southward back into the northern eyewall for Ocean Winds. However, because it was dark, that region of Cuba is mountainous, and the eye was not completely offshore, this portion of the mission was cut short and the plane returned to MacDill without completing much in the way of Ocean Winds. During this last part of the mission, lightning became evident in the eye.

During the ferry back to MacDill, radar clearly showed the beginning of a secondary eyewall on the northern side of the storm, though a secondary wind maximum at flight level was not yet evident. Microwave imagery (Fig. 2) from the closest time after this time clearly shows the secondary eyewall nearly completely formed.

Figure 2: 89 gHz composite from the Aqua satellite over Hurricane Gustav at 0709 UTC, about six hours after the NOAA42 left the storm, showing a secondary eyewall nearly completely encircling the inner one.

Problems :

Mission Data