Tag Archives: Tropical Cyclone Pola

Tropical Cyclone Pola Strengthens to Equivalent of Hurricane/Typhoon

Tropical Cyclone Pola strengthened to the equivalent of a hurricane/typhoon on Wednesday.  At 4:00 a.m. EST on Wednesday the center of Tropical Cyclone Pola was located at latitude 20.2°S and longitude 177.6°W which put it about 170 miles (275 km) west-northwest of Nuku’alofa, Tonga.  Pola was moving toward the south-southwest at 8 m.p.h. (13 km/h).  The maximum sustained wind speed was 85 m.p.h. (135 km/h) and there were wind gusts to 105 m.p.h. (165 km/h).  The minimum surface pressure was 969 mb.

There was a small, circular eye at the center of Tropical Cyclone Pola.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Storms near the core of Pola were generating upper level divergence which was pumping mass away from the tropical cyclone.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Pola.  The strongest rainbands were occurring in the northwestern half of the circulation.  Bands in the southeastern half of Pola consisted primarily of showers and lower clouds.  Winds to hurricane/typhoon force extended out about 40 miles (65 km) from the center of circulation.  Winds to tropical storm force extended out about 160 miles (260 km) from the center.

Tropical Cyclone Pola will move through an environment favorable for support a strong tropical cyclone for another day or so.  Pola will move over water where the Sea Surface Temperature is near 28°C.  It will move through a region where the upper level winds are weak and there will not be much vertical wind shear.  Tropical Cyclone Pola could strengthen during the next 24 hours.  Pola will stat to move over cooler water on Thursday.  An upper level trough will approach Tropical Cyclone Pola from the west.  The trough will produce northwesterly winds which will increase the vertical wind shear.  A combination of cooler water and more vertical wind shear will cause Pola to weaken.  Tropical Cyclone Pola could make a transition to an extratropical cyclone later this week.

Tropical Cyclone Pola will move around the western end of a subtropical ridge over the South Pacific Ocean.  The ridge will steer Pola toward the south-southwest during the next day or two.  Eventually, the upper level trough will turn Tropical Cyclone Pola toward the southeast.  On its anticipated track the core of Pola and the strongest winds will pass west of Tonga.  Rainbands on the eastern side of the circulation could bring gusty winds and heavy rain at times to parts of Tonga.

Elsewhere, Typhoo Wutip continued to weaken west-northwest of the Marianas.  At 4:00 a.m. EST on Wednesday the center of Typhoon Wutip was located at latitude 16.3°N and longitude 139.4°E which put it about 370 miles (595 km) west-northwest of Guam.  Wutip was moving toward the north-northwest at 6 m.p.h. (10 km/h).  The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h).  The minimum surface pressure was 981 mb.