Tag Archives: 11P

Tropical Cyclone Winston Turns Back Toward Fiji

Tropical Cyclone Winston turned northeastward on Sunday and it began to move back toward Fiji.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Winston was located at latitude 22.6°S and longitude 179.9°E which put it about 345 miles (560 km) south-southeast of Suva, Fiji.  Winston was moving toward the northeast at 15 m.p.h. (24 km/h).  The maximum sustained wind speed was 70 m.p.h. (115 km/h) and there were wind gusts to 85 m.p.h. (135 km/h).  The minimum surface pressure was 978 mb.

A subtropical ridge located northwest of Winston generated southwesterly winds over the top of the tropical cyclone.  The southwesterly winds produced moderate vertical wind shear, which caused Winston to weaken on Sunday.  The circulation of Tropical Cyclone Winston remains fairly intact.  A narrow band of thunderstorms is wrapped around the center of circulation and a remnant eyewall persists.  Other bands of thunderstorms are rotating around the eastern side of the cyclone.  Upper level divergence is still pumping mass out from the northeastern side of the circulation.

Tropical Cyclone Winston is currently over water where the Sea Surface Temperature is near 28°C.  As Winston moves northward it will move over warmer water.  It will also move into an area where the upper level winds are not as strong.  Tropical Cyclone Winston could continue to weaken slowly for another 12 to 24 hours.  It may re-intensify in about two or three days.

The subtropical ridge is likely to continue to steer Winston toward the northeast for anther two or three days.  After that time the subtropical ridge may shift position and allow Winston to turn back toward the west.  On its anticipated track Tropical Cyclone Winston could move over the extreme southeastern islands of Fiji on Monday.  It could bring strong winds, heavy rain and large surf to Vatoa, Ono-i-lau, Tuvana-i-colo, and Tuvana-i-ra.  Tropical Cyclone Winston could affect portions of Tonga during the middle of the week.

Tropical Cyclones Winston and Tatiana Form over SW Pacific

A pair of tropical cyclones named Winston and Tatiana formed over the southwestern Pacific Ocean on Thursday.  At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Winston was located at latitude 18.4°S and longitude 171.6°E which put it about 445 miles (720 km) west of Suva, Fiji.  Winston was moving toward the south at 7 m.p.h. (11 km/h).  The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h).  The minimum surface pressure was 974 mb.

At 10:00 p.m. EST on Thursday the center of Tropical Cyclone Tatiana was located at latitude 17.3°S and longitude 159.0°E which put it about 620 miles (1000 km) northwest of Noumea, New Caledonia.  Tatiana was moving toward the east-southeast at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h).  The minimum surface pressure was 982 mb.

Tropical Cyclone Winston is the stronger and more well organized storm.  It has a well developed eye surrounded by a ring of strong thunderstorms.  Winston is in a very favorable environment.  It is moving over water where the Sea Surface Temperatures are near 31°C.  There is an upper level ridge over Winston and so the upper level winds are light and divergence is occurring in all directions.  Winston is likely to continue to intensify rapidly on Friday and it could become the equivalent of a major hurricane.

Tropical Cyclone Tatiana is smaller and not as well organized.  Tatiana is moving over water where the Sea Surface Temperatures are near 30°C.  However the western end of the same upper level ridge that is over Winston is generating brisk northerly winds over the top of Tropical Cyclone Tatiana.  As a result, vertical wind shear is inhibiting upper level divergence to the north of the center of Tatiana and it is also tilting the circulation toward the south with height.  Wind shear is likely to prevent Tatiana from intensifying significantly.

A subtropical ridge is steering both Winston and Tatiana toward the south.  Tropical Cyclone Winston will pass west of Fiji, but it could come close enough to the extreme southeastern islands of Vanuatu to bring wind and rain to some of those islands.  Tropical Cyclone Tatiana is likely to pass west of New Caledonia, but it could bring rain and higher surf to the west coast of that island.