Vertical Wind Shear Starts to Weaken Tropical Cyclone Maha

Increased vertical wind shear started to weaken Tropical Cyclone Maha over the Arabian Sea on Monday night.  At 10:00 p.m. EST on Monday the center of Tropical Cyclone Maha was located at latitude 19.6°N and longitude 63.7°E which put it about 605 miles (1140 km) west of Mumbai, India.  Maha was moving toward the north at 2 m.p.h. (3 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.

Upper level westerly winds of the middle latitudes moved southward over the northern Arabian Sea on Monday night.  Those winds caused increased vertical wind shear and they started to weaken Tropical Cyclone Maha.  The westerly winds began to push the higher clouds toward the east and the eye was no longer visible on infrared satellite imagery.  It also appeared that westerly winds lower in the atmosphere may have been transporting drier air toward the western side of Maha.  The rainbands in the western half of Tropical Cyclone Maha weakened on Monday night and there also appeared to be weakening in the southern part of the eyewall.  The strongest rainband was north of the center of circulation.

The circulation around Tropical Cyclone Maha was fairly small.  Winds to hurricane/typhoon force only extended out 25 miles (40 km) from the center of circulation.  Winds to tropical storm force extended out 95 miles (150 km) from the center.  The small size of Tropical Cyclone Maha means it will weaken more quickly because of the effects of vertical wind shear and drier air.  Maha could weaken to the equivalent of a tropical storm within 24 to 30 hours.

The westerly winds will push Tropical Cyclone Maha back east toward India.  On its anticipated track Tropical Cyclone Maha could approach the coast of India north of Mumbai within three days.  Maha will be a much weaker tropical cyclone by the time it nears India.