KOCHI: The India Meteorological Department has announced the onset of the southwest monsoon over Kerala on Thursday. As per a statement issued by the IMD, the "Southwest monsoon has advanced into some parts of south Arabian Sea, Lakshadweep area, south Kerala, south Tamil Nadu and parts of Comorin on Thursday." However, meteorologists say the monsoon winds have not advanced much into the land and are actually bypassing through coastal areas.
More than 60 percent of the 14 rainfall monitoring stations reported rainfall above 2.5 mm during the past two days consecutively. Also, the spatial distribution of rainfall over Kerala remained to be fairly widespread during these days.
Fulfilling the criteria, the westerly winds have gained strength in the lower levels and the wind has attained a speed of 20 knots. Satellite-derived data suggests that 15-20 knots westerly winds prevail up to a height of 6,000 m. There is persistent cloudiness indicated by outgoing longwave radiation values.
An east-west shear zone runs from the south Arabian Sea to the southeast Bay of Bengal across the southernmost parts of peninsular India in the mid-tropospheric levels. An offshore trough at mean sea level runs off the Karnataka – Kerala coasts.
The monsoon is likely to advance into the remaining parts of the south Arabian Sea, Kerala, Lakshadweep, Tamil Nadu, Puducherry, coastal and south interior Karnataka and Rayalaseema during the next two days.