Monsoon maintains token presence over peninsula

The India Meteorological Department (IMD) on Thursday maintained the watch for a late-September low-pressure area to churn up the Bay of Bengal around Sunday even as the monsoon retained its token presence over the peninsula.

The weather-driving northsouth trough extended from Bihar to coastal Karnataka through Jharkhand, Chhattisgarh, Telangana and interior Karnataka with an embedded cyclonic circulation over Bihar.

BEVY OF TROUGHS

Alargely sea-bound trough extended south from the circulation over Bihar and adjoining West Bengal up to southwest Bay of Bengal. This will have some say in the churning of the Bay and associated birth of the `low.'

The cyclonic circulation over the east-central Arabian Sea off the Karnataka coast has become less marked as of Thursday, but a trough extended south from Konkan towards the Kerala coast.

Satellite pictures showed convective clouds over parts of the north Bay of Bengal, north Andaman Sea and east-central Arabian Sea.

An update from the Chennai Met Centre said the monsoon has been active over interior Karnataka and Rayalaseema during the 24 hours ending Thursday morning.

Rainfall occurred at many places over Kerala, Rayalaseema and interior Karnataka and at a few places over Tamil Nadu and coastal Karnataka. Isolated rainfall occurred over coastal Andhra Pradesh and Telangana.

The forecast for the next two days said that rain or thundershowers are likely at many places over the Andaman and Nicobar Islands.

Rain or thundershowers are likely at many places over Kerala and coastal Karnataka and at a few places over Tamil Nadu, Puducherry, interior Karnataka and coastal Andhra Pradesh.

Isolated rain or thundershowers are likely to occur over Telangana, Rayalaseema and Lakshadweep.

WIDESPREAD RAIN

Given the influence of the varied meteorological features on the immediate vicinity, the IMD has forecast scattered to fairly widespread rainfall activity along the west coast and over interior south peninsular India during the next 24 hours before going into a lull.

This lull would be broken with the formation of the `low' in the Bay from when rains are forecast for peninsular and adjoining central India.

Isolated heavy rainfall is likely over the Andaman and Nicobar Islands, Konkan, Goa and coastal Karnataka during the next 24 hours.

The forecast for the next three days projects the possibility of fairly widespread rainfall with isolated heavy falls over the North-Eastern States.

The three days starting from Sunday until September-end would see the initiation of the `low' over west-central and adjoining northwest Bay. This will lead to an increase in the rainfall along the east coast, peninsular and adjoining central India.

Meanwhile, a forecast about the withdrawal of monsoons from northwest India has become uncertain with the presence of cyclonic circulations - `in situ' or those crossing in from the border.

Any declaration of the withdrawal pre-supposes the total absence of cyclonic circulations over the region and sinking motion of air associated with the setting in of the seasonal anti-cyclone that drives away clouds of any kind.

Dry North-West

Otherwise, dry conditions have settled over the region with many places in Rajasthan recording maximum day-time temperatures of over 40 degrees Celsius.

On Thursday, the IMD traced a `nuisance' cyclonic circulation over north Pakistan and adjoining Jammu and Kashmir, once again preventing the monsoon withdrawal process from getting entrenched.

Meanwhile, the US National Centres for Environmental Prediction (NCEP) has in updated forecasts indicated that the rains over the peninsula may last as late as October 10.

The NCEP expects the churn in the Bay of Bengal to continue at least till such time, with a core wave of rainfall looking to wade its way into Sri Lanka and adjoining south Tamil Nadu and Kerala during this period.

The rest of the peninsula is expected to receive comparatively lesser amount of rain, it said.