Forecasted to be weak and below normal, Monsoon throws up surprises.

South West Monsoon 2015 has till today the 23rd of June 2015 covered more than half the country with the northern limit lying on From West to East - Veraval, Surat, Ratlam, Bhopal, Ambikapur,
Bhagalpur and Supaul, still 5 - 6 days later than normal, although with twin systems in the Bay of 
Bengal and Arabian sea is expected to reach Punjab by the 28th or 29th of June about 3 days earlier 
than normal which will be a big relief for farmers and administration up north. 




The big news though is that the monsoon is currently in excess of 15% for the month and season so far which has caught many by surprise after the outlook by the IMD which was taking into account the effects of an el nino.




The main reasons contributing to the excess and active phase of the monsoon is a mildly strong MJO 
or Madden-Julian Oscillation - An equatorial Indian ocean system of currents that oscillates east to west and at different levels of intensity. The current MJO phase could last till the 26th or 27th of the month.



One more factor for the strong monsoon is a neutral IOD or Indian ocean dipole - again an anomaly in the sea surface temperatures in the Indian ocean which normally tends to counteract the El Nino. The IOD for week beginning the 22nd June showed it moving into a positive phase which should be good for the monsoon for the next week or so as well.




To Summarize, Monsoon should cover most of the country by the end of June with twin systems in 
the bay and Arabian sea, temperatures still very high in Rajasthan and Pakistan with the worst heat 
wave in decades, And a favorable MJO and IOD and a weak el Nino currently.




The next 9-10 days would continue to bring heavy to very heavy rainfall along west coast and 
central India, South India will see a decline in rainfall from today.




Forecast for coming weeks and rest of the monsoon.

Decline in rainfall over south India for next 2 weeks.Increase in rainfall over central and North India.



Strengthening of El Nino and weakening(neutral phase) of MJO and IOD around Second week of July.



July could see below normal rainfall over most of India except for a few places in West coast and North India.

Rains to return to South India & the perseids meteor shower

Rain is forecast for North east and east India, Uttar Pradesh, Uttarkhand and West & South India in the week from 10th - 16th. With some places forecast to get extremely heavy falls. There is a high possibility of a low pressure forming in the bay of Bengal after the 13th of August. Coastal areas of south Tamil Nadu and parts of north interior Tamil Nadu and south interior Karnataka could receive heavy rainfall. 




Also don't forget to watch the sky for the perseids meteor shower which has already begun and will peak between the 10th - 13th of August. Best watched away from city lights from midnight to dawn. To view the shower look NE towards the Perseus constellation, Scientists say up to 60 falling stars can be seen an hour during these days which could get higher when it peaks. The perseids are the brightest meteor showers of the year and promise to be a spectacle weather permitting..

the time has come. the south west monsoon will set in over kerala tomorrow the 31st of May.  IMD will take 24 hours more and declare the onset on 1 St of  June. rain is forecast for most of southern peninsula. Bangalore will get heavy showers on 1st and 2nd. Chennai on the 3rd. onset over Bangalore is the third.

Arrival of the South West Monsoon

The South West Monsoon has arrived over the Andaman and Nicobar islands. IMD will declare its onset within the next 24 hours. 

Two low pressures are forecast to come up on either side of the  peninsula within the next 72 - 96 hours and drag monsoon winds onto the mainland. However, the Arabian sea low is forecast to end up in Oman and could cause a delay of about 2 days in the onset over Kerala. The North-West of the country is heating up considerably and the annual Low pressure area will form over parts of Rajasthan and Madhya Pradesh, further strengthening Monsoon flows on the mainland. 

Expected date of Monsoon onset over Kerala is between 29th and 31st of May.

Cyclone Mahasen and the Onset of the Monsoon

As forecasted a cyclone formed in the bay which was named Mahasen. Mahasen is expected to make landfall between bakkhali in West bengal and chittagong in Bangladesh. Expected time of landfall is estimated between the morning - evening of the 16th of May. Mahasen is expected to strengthen for another 24 hours possibly reaching a maximum strength of T4.0 by Dvorak technique or category 2 on the saffir - simpson scale before it starts to recurve towards the North-East and weaken before making landfall as a deep depression.

 Rain/Drizzles From Mahasen is Expected along the east cost of India from Nagapattiam to Machilipattinam from the Night of 12th May 2013 to the Evening of 14th May 2013. Rain will be generated from localised Thundershowers as Mahasen pulls moisture and from bands of convection breaking off from the main system and hitting the coast. rainfall will move northwards along the coast as Mahasen makes its way north.

Pre-monsoon showers will continue over interior southern peninsula after the exit of Mahasen on the 17th.

SOUTH WEST MONSOON will reach Andaman islands by the 19th/20th of May 2013 aided by a possible low pressure near the east coast of Sri lanka. Some models also predict a Low pressure in the Arabian sea dragging monsoon winds over the mainland.