Tropical Cyclone Sandra (19P) Tracking Southward at 12 Knots
Tropical Cyclone Sandra (19P), located approximately 325 nm southwest of Noumea, New Caledonia, has tracked southward at 12 knots over the past six hours.
Animated enhanced infrared satellite imagery shows the low level circulation center (LLCC) has been fully exposed for the past 18 hours but remains well organized. A recent ASCAT pass indicated 35 to 40 knot winds along the eastern periphery. The current intensity has been maintained above the Dvorak estimates from PGTW, PHFO, and NFFN, which indicate a much weaker system than the ASCAT pass suggests.
Total precipitable water imagery indicates dry air wrapping into the LLCC from the western periphery and has nearly separated the central core of tropical moisture from the larger source of tropical moisture to the northeast. Upper level analysis indicates a trough to the southwest and ridging to the northeast are creating high levels (30 to 40 knots) of vertical wind shear (VWS).
Continued inflow of dry air and high VWS will start the extra-tropical transition process within the next 12 hours, and will be fully extra-tropical by TAU 36. Based on good agreement in the model guidance, there is high confidence in the forecast track. Maximum significant wave height is 20 feet