Tropical Cyclone Gino (15S) at 75 Knot Intensity – February 13th, 20137.7S 75.9E
Tropical Cyclone Gino (15S), located 700 nm southeast of Diego Garcia, has tracked south-southwestward at 10 knots over the past six hours.
Animated multispectral satellite imatery (MSI) shows a ragged eye has developed over the past 12 hours with deep banding wrapping into the low level circulation center (LLCC). A TRMM image supports the recent improvements in organization observed in MSI. Upper level analysis indicates a vigorous radial outflow associated with a point-source anticyclone located over the LLCC, which is also creating a low vertical wind shear (VWS) environment.
The current intensity is based on Dvorak estimates from PGTW and KNES indicating 75 knots. TC 15S continues to track around the northwest periphery of a deep-layered subtropical ridge (STR) and is expected to continue tracking around the STR through the forecast period.
Sea surface temperatures (SSTs) are currently favorable (28 degrees Celsius) but will steadily decrease over the next 72 hours, becoming unfavorable by TAU 36. In addition, VWS is expected to increase as a mid-latitude trough approaches from the southwest, becoming unfavorable (greater than 30 knots) by TAU 48.
Extra-tropical transition is forecast to begin by TAU 48 as decreasing SST values, increasing VWS, and the approaching trough lead to the transition of the system to a cold-core low by TAU 72. Model guidance is in fair agreement leading to high confidence in the JTWC forecast track. Maximum significant wave height is 23 feet.