Temperatures have been rising over the eastern parts of the country over the past few days, especially Assam, Andhra Pradesh, north Tamil Nadu, parts of the north-east and extreme south peninsular India.
The maximum temperatures have reached 40 deg Celsius over some parts of Andhra Pradesh and isolated pockets of Vidarbha, according to an update by India Meteorological Department (IMD).
FINE OVER NORTH-WEST
But the benign presence of western disturbances, one of which is affecting north-west India, has continued to shield the region and its standing wheat crop from the extreme weather (to within the 30 to 25 deg Celsius range).
The cloudiness associated with the systems has had a calming impact on ambient temperatures.
The next one in the series of western disturbances is expected to roll into the north-west over the next 24 hours, the IMD update said.
It has also joined international models in the outlook for yet another western disturbance, a moderately intense one, around mid-week.
Maximum temperatures over north-west and adjoining east India are expected to fluctuate coinciding with the arrival and exit phases of the westerly systems.
While the moisture and associated cloudiness brought in by the incoming system tend to cap maximum temperature levels, its exit takes away the clouds leading to rise in the ambient temperature levels.
On Sunday, strong north-westerly to westerly winds were prevailing over parts of the Indo-Gangetic plains.
The strong winds are likely to prevail over the next 2-3 days as well, the IMD forecast said.
Similarly, the prevailing western disturbance is likely to continue to affect the western Himalayan region on Monday too.
Satellite imagery showed low to medium clouds over western Himalayan region and the north-eastern States.
Isolated rain or snow has been forecast for Jammu and Kashmir, Himachal Pradesh and Uttarakhand during the next 24 hours.
Scattered rain or thundershowers are likely over parts of the north-eastern States during the next two days.
While a fall in minimum temperatures is seen over north-west and adjoining central and east India during the next three days, a rise in maximum temperatures is forecast over north-west and adjoining central and east India.
Meanwhile, international models indicated a trend in which east and peninsular India would witness sustained heating in the medium term.
This is forecast to start propagating to the west and north-west in phases.
The International Research Institute (IRI) at Columbia University and the European Centre for Medium-Term Weather Forecasting (ECMWF) are in agreement with this outlook.
Seasonal forecast by the IRI for the summer months seems to pack a pleasant surprise for east India in as much as it sees only low probability of a deadly heat wave stalking the traditional backyard encompassing Orissa, coastal Andhra Pradesh and adjoining Vidarbha.
‘Open hearth' conditions might shift elsewhere, with the highest probability for significant above-normal heating being indicated for coastal and southern tip of Tamil Nadu, the west coast and south and south-west Gujarat during April, May, June.
The heating process would start lifting gradually in the run-up to the onset of the south-west monsoon although extreme south peninsula and Gujarat might still witness flare-ups on the home stretch.
As for monsoon rains, the IRI maintained the outlook for maximum probability for normal rainfall going into June-July-August, though the onset phase in April-May-June tends to show some deficiency for eastern parts of the country – especially, Bihar, Jharkhand, Chhattisgarh, Orissa and Gangetic West Bengal.