Tropical Cyclone 13P Develops Over the Coral Sea

Tropical Cyclone 13P developed over the Coral Sea northwest of New Caledonia on Monday.  At 5:00 p.m. EDT on Monday the center of Tropical Cyclone 13P was located at latitude 17.2°S and longitude 159.7°E which put it about 550 miles (885 km) northwest of Noumea, New Caledonia.  It was moving toward the south at 11 m.p.h. (17 km/h).  The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h).  The minimum surface pressure was 998 mb.

A distinct low level center of circulation developed within an area of showers and thunderstorms over the Coral Sea on Monday.  The strongest rainband extended from northeast of the center, south of the the center and then west of the center.  Additional rainbands were forming in other part of the circulation.  Storms near the center of circulation were beginning to generate upper level divergence which was pumping mass away to the south of the tropical cyclone.

Tropical Cyclone 13P will move through an environment favorable for intensification on Tuesday.  It will move over water where the Sea Surface Temperature is near 29°C.  An upper level trough near the east coast of Australia is producing northerly winds which are blowing toward the top of the circulation.  The core of Tropical Cyclone 13P is east of the strongest upper level winds, but the winds are causing moderate vertical wind shear.  Despite the vertical shear, the tropical cyclone is forecast to intensify during the next 24 hours.

Tropical Cyclone 13P is moving around the western end of a subtropical ridge which is steering it toward the south.  There is some variability in the guidance from the numerical models about the future strength of the ridge.  Some models do not strengthen the ridge much and those model predict that Tropical Cyclone 13P will move almost straight southward.  Other models increase the strength of the ridge and steer the tropical cyclone more toward the south-southwest.  A general motion toward the south or south-southwest seems most likely during the next 24 to 36 hours.  On its anticipated track the core of Tropical Cyclone 13P would pass west of New Caledonia, but it could move closer to the east coast of Australia.