Extremely heavy rain is likely over many places in coastal and south interior Karnataka on Friday, India Meteorological Department (IMD) has warned.
Very heavy rain is also likely over Kerala, coastal and south interior Karnataka between Thursday and Saturday.
An off-shore trough—an area of low pressure —is running between coastal south Maharashtra and north Kerala.
The east-west shear zone, which denotes a change in wind direction and velocity, is running across peninsular India and a cyclonic circulation is lying over east-central Arabian Sea off coastal Karnataka.
IMD is expecting heavy rains in peninsular India for the next three-four days due to these favourable conditions.
The weather bureau has issued an orange category warning for parts of Karnataka and Kerala, Assam and Meghalaya on Thursday and Friday. The warning implies that disaster management authorities should be prepared for any heavy rain-related disasters such as flooding.
The monsoon trough is lying to the north of its normal position (from Rajasthan’s Ganganagar to the Bay of Bengal).
A cyclonic circulation is also lying over Gangetic West Bengal and neighbourhood in the lower troposphere.
Widespread rain with thunderstorm and lightning is very likely over the north-east and adjoining eastern India.
Heavy rainfall is expected at isolated places over sub-Himalayan West Bengal and Sikkim during the next five days and over most north-eastern states during the next four-five days.
A low-pressure area is likely to form over west-central Bay of Bengal off Andhra Pradesh (AP) coast around September 13. The weather phenomena will lead to rainfall distribution and the intensity is likely to increase over Odisha, coastal AP, Yanam in Puducherry, Telangana, Vidarbha and adjoining areas from September 12 onwards.
In September, rainfall is likely to range between normal and above normal, as the four-month-long south-west monsoon prepares for a retreat, IMD had said on Monday.
Rainfall is likely to be deficient at least until September 13 in most parts of the country, including north-west and central India, before intensifying after September 17, according to the IMD’s extended range forecast.
Usually, the retreat of monsoon is slated to begin from September 17 when rain begins reducing across the country until a complete withdrawal by October 15.
However, this year IMD’s extended range forecast shows extensive and heavy rains along the west coast between September 11 and 24 and then until October 1 over several parts of central India.