Conditions are also becoming favourable for further advance of Southwest Monsoon

New Delhi: According to the National Weather Forecasting Centre/Regional Meteorology Centre, New Delhi of the India Meteorological Department:

Progress of Southwest Monsoon 2020 and its forecast till 17th June 2020

Advance of Southwest Monsoon till 12th June, 2020

  • Southwest Monsoon has set in over Kerala on 1st June, 2020 (coinciding with its normal date), thereafter it advanced & covered entire Kerala, Tamil Nadu, Karnataka, Goa, Puducherry, Telangana, Andhra Pradesh, northeastern states, most parts of Odisha, West Bengal, Sikkim and some parts of Maharashtra and Chhattisgarh as on 12th June, 2020.
  • The Northern Limit of Monsoon (NLM) passes through Lat.18°N/Long.60°E, Lat.18°N/Long.70°E, Harnai, Baramati, Beed, Wardha, Raipur, Sambalpur, Baripada, Bardhaman, Siliguri, Lat.27°N/Long.87.5°E on 12th June, 2020 (Annexure I).
  • It has been nearly normal advance over most part of the above region except northeastern states where it has been delayed by 6-days.

Southwest Monsoon till 11th June 2020:

 

For the country as a whole, Seasonal cumulative rainfall during this year’s southwest monsoon till 11th June 2020 is above Long Period Average (LPA) by 34%. It is above by 42%, 95% & 28% above their LPA over northwest, central & south peninsular India respectively. Details of the rainfall distribution over the four broad geographical regions of India are given below (Annexure II):

 

Regions          ActualRainfall(mm)               NormalRainfall(mm)%Departure fromLPA

 

Country as a whole 55.8                             41.6                                         34%

 

Northwest India                    23.1                             16.3                                         42%

 

Central India              61.0                             31.3                                         95%

 

South Peninsula                   62.1                             48.6                                         28%

 

East & northeast India         99.9                             103.6                                       -4%


 

The timely progress of southwest monsoon is due to formation two low pressure systems, one over southeast Arabian, which intensified upto a Severe Cyclonic Storm, NISARGA,

crossed South Maharashtra coast during 2-5 June 2020 and another system over eastcentral Bay of Bengal & moved towards south Odisha coast during 7-12 June 2020.

Forecast & Warnings

  • The low pressure area lies over north Coastal Andhra Pradesh, adjoining Coastal Odisha & neighbourhood.
  • An east-west shear zone lies between 3.1 & 7.6 km above mean sea level tilting southwards with height and runs roughly along Lat.17°N across Peninsular India at 3.1 km above mean sea level.

— Under the influence of above systems,

a) Scattered heavy to very heavy with isolated extremely heavy rainfall (≥ 20 cm) very likely over Konkan & Goa and Isolated heavy to very heavy rainfall over Madhya Maharashtra, Marathawada, Coastal Andhra Pradesh & Yanam, North Interior Karnataka,

Chhattisgarh, Telangana, Vidarbha, Assam & Meghalaya during next 24 hours; scattered

heavy to very heavy with isolated extremely heavy rainfall likely over Vidarbha and Isolated heavy to very heavy rainfall over Coastal Karnataka, Madhya Maharashtra, Chhattisgarh, Telangana, Assam & Meghalaya during subsequent 24 hours.

 

b) Conditions are also becoming favourable for further advance of Southwest Monsoon into some more parts of Central Arabian Sea, remaining parts of Maharashtra (including

Mumbai), Odisha and West Bengal, some more parts of Chhattisgarh and some parts of

south Gujarat State, south Madhya Pradesh, Jharkhand and Bihar during next 48 hours.

 

[Heavy rain: 64.5-115.5 mm/day; isolated rain (≤25% of stations gets rain), scattered or at a few places rain (26 to 50% of stations gets rain), at many places or fairly widespread rain (51–75% of stations gets rain) and at most places or wodespread rain (>75% of stations gets rain)]