NASA Eyes the Birth of Tropical Cyclone Haley

On Feb. 9 at 2020 UTC (3:20 p.m. EST) the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard NASA's Terra satellite captured a visible image of System 93P (known in Fiji as 14F). The MODIS image showed a circular center of circulation with banding features, two things that indicated that the low pressure area was quickly organizing. The next day, the low became Tropical Storm Haley.

Tropical Cyclone Haley formed on Feb. 10 at 0300 UTC, about 325 nautical miles (374 miles 602 km) south-southwest of Bora Bora, Society Islands, French Polynesia, in the open waters of the South Pacific Ocean. Maximum sustained winds strengthened quickly to 45 knots (51.7 mph/83.3 kph). Soon after Haley intensified, infrared satellite imagery indicated that convection (rising air that forms thunderstorms that make up the storm) were already weakening around the center.

On Feb. 11 at 0300 UTC, the Joint Typhoon Warning Center issued its final advisory on Tropical Cyclone Haley. At that time, Haley's center was located near 24.8 south latitude and 150.0 west longitude, about 500 nautical miles (575.4 miles/926 km) southeast of Bora Bora, Society Islands. Haley was moving to the southeast at 11 knots (12.6 mph/20.3 kph). As a result of wind shear and cooler sea surface temperatures, Haley's maximum sustained winds had already dropped to 35 knots (40.2 mph/64.8 kph).

The forecasters at the Joint Typhoon Warning Center expect Haley to continue moving southeast as wind shear increases and sea surface temperatures become even cooler. Both of those factors are expected to dissipate Haley by Tuesday, Feb. 12.

Text Credit: Rob Gutro
NASA's Goddard Space Flight Center