Tropical Cyclone Narelle (08S) Expected to Intensify12.4S 123.9E
Tropical Cyclone Narelle (08S) located approximately 610 nm north-northeast of Learmonth, Australia, has tracked westward at 7 knots over the past six hours. Maximum significant wave height is 20 feet.
Animated infrared (IR) satellite imagery indicates a rapidly consolidating low-level circulation center (LLCC) located under a central dense overcast feature with improved deep convective banding over the western semi-circle of the system. An AMSU-B microwave image shows deep convection surrounding a formative microwave eye feature. There is good confidence in initial position based upon the eye feature in the microwave imagery.
TC 08S is located equatorward of the upper-level ridge axis and is under weak to moderate (10 to 20 knots) east-northeasterly vertical wind shear with improved poleward outflow into a deep midlatitude trough positioned west of Australia. The initial intensity is assessed at 55 knots based on congruent Dvorak intensity estimates of 55 knots.
Narelle is forecast to track south to southwestward under the steering influence of the low- to mid-level subtropical ridge positioned southeast of the system. Dynamic model guidance is tight agreement with the exception of the GFDN, which tracks the system well west of the other models and at slower speeds. Overall, there is high confidence in the JTWC forecast track. TC 08S is expected to rapidly intensify under favorable environmental conditions and reach a peak intensity of 130 knots by TAU 72.