Thiruvananthapuram, April 13 The Application Laboratory of the Japanese national weather forecaster Jamstec has indicated that parts of the South Peninsula, Gujarat and adjoining Central India (West Madhya Pradesh) as well as North-West India may witness an indifferent monsoon this year.
The weak monsoon signal will be on show predominantly into the second half of the monsoon (August-September) after a satisfactory pre-monsoon season (March-April-May) and the first monsoon month of June, the Japanese forecaster said.
IMD forecast awaited
Private forecaster Skymet Weather had on April 12 come out with its monsoon outlook (June-September) predicting a ‘normal’ season (rainfall amounting to 98 per cent of the normal), but marked by wide spatial variability.
This would come into play after the ongoing helpful La Nana conditions in the tropical Pacific (warmer in the West basin than in the East) start to wear off from June and closer home, neutral Indian Ocean Dipole (IOD) conditions deteriorate.
India Meteorological Department (IMD) is expected to announce its first monsoon forecast anytime from now even as a heat wave shows signs of relent briefly and seasonal thunderstorms roam the South Peninsula and East and North-East.
Negative IOD likely
The Japanese agency suspects that the neutral IOD conditions may give way to a negative IOD (warmer in the East basin than the West) later into the summer, considered prejudicial for a concurrent Indian monsoon. Skymet Weather tends to agree with this outlook.
Skymet had said the IOD is currently neutral, but has a propensity to approach the threshold of being negative. A neutral Pacific and an unstable IOD will combine to cause extreme variability in the monthly rainfall distribution. Earlier, the Busan, South-Korea-based APEC Climate Centre had pointed to likely monsoon reverses for Kerala, Tamil Nadu, Rayalaseema, North interior and Coastal Karnataka, Marathawada and Goa.
July and August, respectively considered the rainiest and second-rainiest months of the monsoon, may bear this out, the South Korean agency had said, though it expects some order (in the form of better rains) to return in September. South Kerala and adjoining Tamil Nadu may continue to experience deficient rainfall in September. This should go to rule out excess rain and floods witnessed over these states in the immediate past years, notably the Great Flood of 2018.