Wednesday, June 16, 2010

North-West may have to wait until early July for rains

A four-day lull in south-westerly flows across the South-East Arabian Sea from Saturday could delay the onset of the monsoon over parts of North-West India.
Seasonal rains should normally cover the entire land mass by June 30, but may just stop short of achieving it this time around.
This is as per updated predictions from the US National Centres for Environmental Prediction (NCEP).

The whole of Rajasthan, north Gujarat and adjoining west Madhya Pradesh may likely find themselves waiting until early July for the onset of monsoon locally.
The lull in the flows over the Arabian Sea would have repercussions for the Bay of Bengal as well, delaying the formation of a suitably endowed ‘low' to turn around things from that end.
The ‘twin-engine' scenario wherein the monsoon catapults itself into active status powered by ‘low's on either side of the peninsula, may not unfold until June 25, according to the European Centre for Medium-Range Weather Forecasting.
A western disturbance system is tipped to cross into northwest India around that time. It would dig deep into the Arabian Sea and the Bay to activate the ‘low's.
Ahead of this, the monsoon flows are shown to resume in full strength from June 22 and peak by June 25, setting the ground for system generation.

The International Research Institute (IRI) for Climate and Society at Columbia University has shifted further to the north along the west coast its watch for flooding rains.
A six-day outlook until Saturday suggested above normal rains are likely for north Konkan, Mumbai, south and south-west Gujarat.
However, the IRI did not see rainfall amounts exceeding 10 to 12 cm for Mumbai any time during this period.
On Sunday, Dr Akhilesh Gupta, leading operational forecaster and Advisor to the Ministry of Science and Technology, told Business Line that it was too early to expect exceptional rains (exceeding 25 cm) for Mumbai.
The city is used to rains amounting to 10 cm during the monsoon, but torrential rains capable of throwing normal life out of gear can happen only during the latter stages when the monsoon flows “mature”.

The NCEP precipitation outlook suggested that, despite the brief weakening of flows, thundershowers could break out occasionally along the west coast through the next week.
The convective available potential energy (CAPE) values, which indicate the relative potential for thundershowers, are the maximum around the Konkan and Gujarat.
In fact, the US Navy Operational Global Atmospheric Prediction System (Nogaps) model suggested the possibility of a ‘low' spinning up in the northeast Arabian Sea and washing ashore along the Mumbai-south Gujarat coast during the period under reference.
India Meteorological Department (IMD) said in an update on Tuesday that the northern limit of the monsoon passed through Mumbai, Aurangabad, Adilabad, Jagdalpur, Phoolbani, Keonjhargarh, Burdwan, Malda and Gangtok.
The alignment was unchanged from the previous day, the IMD added.
It warned of isolated heavy to very heavy rainfall over Madhya Maharashtra, Konkan, Goa and coastal Karnataka during the next two days.
The outlook until Friday suggested that widespread rain or thundershowers are likely over Madhya Maharashtra, Marathwada, coastal Karnataka, Konkan and Goa.
Fairly widespread rain or thundershowers may occur over Saurashtra, Gujarat, Kerala, Lakshadweep, Andaman and Nicobar Islands and the Northeastern States.
Scattered rain or thundershowers are likely over Madhya Pradesh, interior Karnataka, Andhra Pradesh, Bihar, Jharkhand and Chhattisgarh, Orissa, Vidarbha, West Bengal and Sikkim.
An intervening western disturbance would bring scattered rain or thundershowers over Jammu and Kashmir, Himachal Pradesh and Uttarkhand.
Isolated dust storm or thunderstorms may also occur over Punjab, Haryana, Delhi, Uttar Pradesh and Rajasthan.

No comments:

Post a Comment