Monsoon seen racing into Konkan by week-end

The stage has been set for a steady and sustained revival of the monsoon with erstwhile super cyclone ‘Phet' finding the going difficult after having been undermined by ruthlessly strong upper air westerlies.
Weakened as a depression, ‘Phet' is now easing up along the Makran coast - across the Gulf of Oman and adjoining north Arabian Sea - for a quite landfall over the Sindh-North Gujarat border early on Monday morning, model forecasts said.
But it would still be able to unleash heavy to very rainfall all across an arch stretching north-northeast from north Gujarat, Rajasthan, Delhi, Haryana, Punjab, Himachal Pradesh and parts of west Uttar Pradesh over the next few days.
The US National Centres for Environmental Prediction (NCEP) has estimated that these areas might witness 200 to 600 per cent above the average rainfall for the week ending June 11.
Thus, north-west India would have a lot to cheer about some non-seasonal but bonus rainfall even as regrouping monsoon flows make their presence felt over the Arabian Sea and the Bay of Bengal across south peninsular India during this period.
A monsoon-boosting Madden-Julian Oscillation (MJO) wave is seen providing adequate cover from the upper levels for the flows to gradually progress northward over peninsular India.

ON AUTO-PILOT


According to international models, the MJO wave, the eastward propagating wave with alternating wet and dry phases, would be active over the peninsular seas until Wednesday (June 9) and head towards South China Sea-West Pacific.
Before doing so, it would have powered the monsoon system to an auto-pilot to propel itself towards the north peninsular India and Konkan coast by June 11 (Friday).
India Meteorological Department said in its outlook until June 11 that fairly widespread rainfall activity would occur over Madhya Maharashtra, Konkan, Goa, coastal Karnataka, the Northeastern States and Andaman and Nicobar Islands.
Mumbai, and for the second time this season Gujarat, are forecast to witness a surge in monsoon flows and heavy rains during the week starting from June 12. Northeast India, too, would get drenched in this manner during this period.
A sure sign of the monsoon being prospectively able to fire on its own after the MJO leaves the Indian Ocean region is the projection for Outgoing Long-wave Radiation (OLR) for peninsular India.



According to linear inverse modelling by the Earth System Research Laboratory under the US National Oceanic and Atmospheric Administration, the OLR would be consistently negative, a proxy for cloudiness and possible rainfall, over the entire peninsula until June 26, up which forecasts were available.
The next wet phase of the MJO wave is forecast to envelop the Indian Ocean region by July 15 only, according to the Empirical Wave Propagation model employed by the NCEP.
The Climate Prediction Centre of the US National Weather Services is of the view that the monsoon might manage to cover north peninsular India during the week ending June 13.
Central India and adjoining east India would need to wait until the following week (June 14-20) for sustained rains.
The European Centre for Medium-Range Weather Forecasts sees strong monsoon flows heading into a likely ‘low' off Gujarat from June 15 to set off heavy rains over Mumbai-south Gujarat.
The Arabian Sea flows would be ably supported on the Bay of Bengal side to bring the monsoon into central and adjoining east India subsequently.