Tropical Cyclone Emang (09S) Picks Up Speed11.1S 77.3E
Tropical Cyclone Emang (09S), located approximately 525 nm east- southeast of Diego Garcia, has tracked westward at 05 knots over the past six hours. Maximum significant wave height is 13 feet.
Animated infrared (IR) satellite imagery depicts a partially-exposed low-level circulation center (LLCC) with a recent flare of convection over the northwest quadrant of the LLCC. The initial position based on the IR imagery and extrapolation from an ASCAT pass with fair confidence.
The initial intensity remains assessed at 35 knots based on Dvorak intensity estimates of 35 knots and is consistent with storm structure as organization has not improved over the past 12 hours. Upper level analysis reveals TC 09S is located within a marginal environment with poor outflow and moderate (10-20 knots) vertical wind shear. The system remains within a weak steering environment but has picked up speed over the last six hours tracking westward under the influence of a building subtropical ridge (STR) to the south.
TC 09S is expected to slowly track southwestward by TAU 12 along the northern periphery of this building STR. After TAU 48, the system should track more west- southwestward as the steering STR responds to deep mid-latitude trough. Emang is expected to intensify slowly to a peak intensity of 65 knots by TAU 120 under the moderately favorable environmental conditions throughout the forecast period. Dynamic model guidance is in fair agreement with continued differences in track speed, as the European models are showing a slower track westward. Low confidence remains in the JTWC forecast track due to the differences in track speeds in the models and the past erratic motion, but is improving based on the recent increase in motion.