Tropical Cyclone Maha Strengthens into Equivalent of a Major Hurricane

Tropical Cyclone Maha strengthened into the equivalent of a major hurricane on Sunday night.  At 10:00 p.m. EST on Sunday the center of Tropical Cyclone Maha was located at latitude 18.2°N and longitude 64.8°E which put it about 525 miles (845 km) west of Mumbai, India.  Maha was moving toward the northwest at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 115 m.p.h. (185 km/h) and there were wind gusts to 145 m.p.h. (230 km/h).  The minimum surface pressure was 958 mb.

Tropical Cyclone Maha continued to intensify on Sunday and it became the equivalent of a major hurricane.  There was a small eye at the center of circulation.  The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the core of Tropical Cyclone Maha.  The strongest rainbands were in the eastern half of the tropical cyclone.  Bands in the western half of Maha consisted primarily of showers and lower clouds.  Storms near the core of the circulation were generating upper level divergence which was pumping mass away from the tropical cyclone.

The circulation around Tropical Cyclone Maha was relatively small.  Winds to hurricane/typhoon force extended out 20 miles (35 km) from the center of circulation.  Winds to tropical storm force extended out 75 miles (120 km) from the center.  The Hurricane Intensity Index (HII) for Tropical Cyclone Maha was 20.6.  The Hurricane Size Index (HSI) was 6.6 and the Hurricane Wind Intensity Size Index (HWISI) was 27.2.  Maha was capable of causing localized major damage.

Tropical Cyclone Maha will move through an environment favorable for intensification for another 12 to 18 hours.  Maha 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 be little vertical wind shear.  Tropical Cyclone Maha may be pulling drier air into the western half of the circulation, which could be the reason for the lack of thunderstorms in that half of the circulation.  The drier air could prevent significant additional intensification if it gets pulled into the core of the circulation.  An upper level trough will approach Maha from the west in about 18 hours.  The trough will produce stronger westerly winds which will cause the vertical wind shear to increase.  Tropical Cyclone Maha will begin to weaken when the wind shear increases.

Tropical Cyclone Maha will move around the western end of a ridge of high pressure over India and the eastern Arabian Sea during the next 24 hours.  The ridge will steer Maha slowly toward the northwest.  When the upper level trough approaches Tropical Cyclone Maha, the westerly winds will steer the tropical cyclone back toward the east.  On its anticipated track Maha could approach the coast of India north of Mumbai in about 72 hours.