Monsoon trough travels further North

The monsoon trough over North India has continued to move further north of its usual position, with rains becoming weaker over large parts of Central India. The India Met Department (IMD) said this morning the monsoon trough may shift slightly further northwards today and remain there during the next two to three days.

EXTREMELY HEAVY RAIN

Presence of the trough in the area may bring extremely heavy falls at isolated places along the foothills of Uttarakhand, East Uttar Pradesh, Bihar, Bengal, Sikkim and Meghalaya until tomorrow. The northern parts of Uttar Pradesh, Bihar, Punjab, Haryana and Chandigarh may also witness rains with isolated heavy to very heavy falls during this period.

The trough can be brought down to its usual position by a suitably endowed cyclonic circulation/ low-pressure area positioned in the Bay of Bengal. It remains to be seen whether the current circulation over the West-Central Bay would mould itself in this manner and host one end (southern) of the trough in the Bay and pull it back to its usual alignment.

The trough as of today linked Ludhiana, Najibabad, Bahraich, Gorakhpur, Sheohar, Supaul, Golpara, Dibrugarh and Arunachal Pradesh, having strayed way off the normal. This cuts across the states of Punjab, Uttar Pradesh, Bihar and Assam. In the normal position, it should connect Rajasthan, Madhya Pradesh and Chhattisgarh, before dipping into the Bay.

The US Climate Prediction Centre has suggested that North Coastal Andhra Pradesh or adjoining South Odisha may continue to witness some activity into the next week.

RAINS FOR EAST

The northward shift of the trough in this manner, however, has been known to open up the East Coast - including Odisha, Andhra Pradesh and Tamil Nadu - for enhanced rain activity. The presence of a circulation in what is considered a vantage point over the West-Central Bay off the South Odisha and North Andhra Pradesh coasts is, therefore, attracting some interest.

The Met subdivisions of coastal Andhra Pradesh, Tamil Nadu and Vidarbha (East Maharashtra) are expected to immediately benefit over the next few days, the IMD update said. During the latter part of the week, the ongoing rainfall over the northern parts of the West Coast are forecast to spill over into the southern parts and the adjoining interior as well.

In fact, what has apparently prevented the current weather pattern from being classified as a typical 'break monsoon' phenomenon is the presence of rain over the West Coast.

During a 'break monsoon,' the rain shuts out completely over the region, and is confined to the foothills of the Himalayas, parts of the East Coast and the South Peninsula. Even this is a normal monsoon feature that reveals itself in August. IMD has already said July could yield normal rainfall (101 per cent of the long-period average).