The wait for an anticipated revival of the North-East monsoon continues over the South Peninsula even as day and night temperatures began to fall appreciably over North India, in contrasting trends attributed to entrenching La Nina conditions in the tropical Pacific.
Dry and cold north-westerly winds from across the international border are bringing in the chill and lowering night temperatures over North India. Cold wave conditions have been forecast over Haryana and Delhi on Wednesday; and over Haryana, Punjab and North Rajasthan on Thursday.
Rain in Ghat regions
In the South, the 24 hours ending on Tuesday morning saw some Ghat regions of Tamil Nadu bordering Kerala receiving moderate to heavy rainfall. Thundershowers have been reported on Tuesday afternoon from Maraimlainagar in Chennai.
The Chennai Regional Meteorological Centre said that Coonoor topped the charts with 6 cm of rain until Tuesday morning, while Coimbatore Airport recorded 2.7 cm; Kodaikanal (0.58 cm) and Udagamandalam (.54 cm). Heavy rain may lash Tamil Nadu and Puducherry on Wednesday.
As part of its all-India forecast, the India Meteorological Department (IMD) maintained the watch for the strengthening of north-easterly winds from Wednesday and escalation of rain with fairly widespread rain, isolated thunderstorm and lightning are likely over Tamil Nadu and Kerala.
The IMD said that isolated heavy rainfall might lash Tamil Nadu for five days from Tuesday, and over Kerala for six days from the same day. A La Nina year, of which 2020 is one, has been associated with less than usual rainfall for the South Peninsula, though with exceptions.
La Nina impact on rainfall
Private forecaster Skymet Weather likened the scenario with 2016 marked by a weak La Nina and negative to near normal IOD (Indian Ocean Dipole). But it doesn’t necessarily mean a washout (-62 per cent in 2016) since the North-East Monsoon has its own internal dynamics to prove otherwise.
Skymet expects the rainfall distribution is expected to be skewed amongst the five meteorological sub-divisions and likely staying below normal. The South Asian Climate Outlook Forum too had said that the season could end up indifferent over parts of the South Peninsula.