Tropical Cyclone Eight (08S) Forms Off Coast of Australia – January 8th, 201315.2S 120.2E
Tropical Cyclone Eight (08S), located approximately 700nm north-northeast of Learmonth, Australia, has tracked west-southwestward at 7 knots over the past six hours (click here for previous images). Maximum significant wave height is 12 feet.
Animated infrared satellite imagery shows a consolidating low level circulation center (LLCC), with improved convective bands wrapping around the LLCC and deepening central convection. An AMSU-B microwave image shows increasing organization around the LLCC as the LLCC has become better defined.
The initial position is based upon the aforementioned imagery with fair confidence. The initial intensity is slightly higher than congruent Dvorak intensity estimates of 30 knots from all agencies based upon the improved structure.
Upper level analysis indicates TC 08S is under a highly diffluent region of the subtropical ridge, providing good outflow and low (05-10 knot) vertical wind shear (VWS). Additionally, an upper-level low southwest of Australia is enhancing the poleward outflow. Sea surface temperatures (SSTs) are favorable for intensification at 30 to 31 degrees Celsius and remain favorable until south of 22S where they begin to rapidly decline.
TC 08S is currently tracking west- southwestward along a northwest periphery of a deep layered subtropical ridge to the southeast over Western Australia. The system will continue to track west-southwest and increasingly take a more southern track as the current steering ridge reacts to several transient mid-latitude troughs passing to the south.
TC 08S will increase to a peak of 125 knots by TAU 96 as favorable environmental conditions of low VWS, good outflow and high SSTs are forecast. Dynamic model guidance is in fair agreement with the southwestern track but disagree slightly on the extent of the poleward turn. The JTWC official forecast is close to multi-model consensus. Due to the spread in solutions among the models on the extent of the southern turn, forecast confidence is low.