Tropical Cyclone Nilofar Weakening Rapidly Over the Arabian Sea

Strong southwesterly winds in the upper troposphere are generating vertical wind shear over the top of Tropical Cyclone Nilofar.  The wind shear is blowing the upper part of Nilofar’s circulation northeast of the low level center of circulation and causing the tropical cyclone to weaken rapidly.  At 8:00 a.m. EDT on Thursday the center of Tropical Cyclone Nilofar was located at latitude 20.3°N and longitude 64.5°E which put it about 350 miles south-southwest of Karachi, Pakistan and about 550 miles west of Mumbai, India.  Nilofar was moving toward the northeast at 7 m.p.h.  The maximum sustained wind speed was 50 m.p.h. and there were wind gusts to 65 m.p.h.

An upper level trough to the northwest of Nilofar is pushing strong southwesterly winds over the top of it.  There is evidence on satellite imagery that the wind shear may be strong enough to detach the upper portion of Nilofar’s circulation and transport it northeast of the low level center.  When the upper portion of the circulation is sheared away and detached, it removes the warm core and eliminates the ability of the cyclone to pump out the mass which is converging on the low level center.  If the wind shear were to lessen, Nilofar might be able to re-establish the link between the circulation in the lower and upper levels.  However, the wind shear is not expected to diminish and so Nilofar is likely to continue to weaken.  It may no longer meet the criteria to be classified as a tropical cyclone in another 24-48 hours.

The lower level circulation of NIlofar is expected to continue toward the northeast in the short term.   If the lower level circulation becomes shallow enough, then the southwesterly winds in the upper levels could blow over the top of it.  If that happens, then the lower level circulation could drift in the northern Arabian Sea until it spins down.  Some of the moisture associated with the circulation of Nilofar could get transported into parts of eastern Pakistan and western India where it could enhance precipitation.