Sunday 22 May 2016

S W Monsoon 2016 outlook for Goa - as per the Weather Blog "Vagaries of Weather"

Every year beginning mid April, the well known weather blogger Mr Rajesh Kapadia publishes in his blog "Vagaries of Weather" at http://www.vagaries.in, a series of posts aptly named as Monsoon Watch, analysing the synoptic conditions affecting the setting in of the S W Monssons over the Indian Sub Continent.

The fourth part of the series was posted on May 21 and gives a clearer picture of the onset of the monsoons. The article can be accessed here.

The main highlights of the monsoon onset this year are:

Synoptic situation as on May 21, 2015:
(1) Cyclonic storm ROANU in the Bay of Bengal, which brought copious rains to the East Coast, has weakened into a deep depression over Mizoram and is further expected to weaken into a well marked low pressure area over north east.
(2) The Bay of Bengal branch of the Monsoons has arrived in the Andamans on time
(3) Heat wave continues in the NW including Rajashan, Gujarat as also in Sindh in Pakistan, with temperatures crossing 50C. The seasonal low measuring 996/994 hPa is in place.
(4) Pre monsoon convective activity is seen over central and Penninsular India due to presence of wind discontinuity
(5) Equitorial Cross winds are now well organised. Somali Current is in place.
(6) El Nino conditions are weakening



Based on his experience and deep understanding of the various parameters affecting the onset and quantum of the S W Monssons, as detailed by him in his blog post, Mr  Rajesh Kapadia gives his estimate for the onset of monsoons and quantum of rains up to July 2016 as under:





Mr Kapadia expects that by June 15 S W Monsoon will advance from Kerala, throught upto Central India, into NE States and West Bengal. He expects Monsoon to advance into Central India and North India between June 20th and 30th.

For Goa the analysis presented in Vagaries of Weather would imply:

1. Onset of Monsoon by June 10, and
2. Slightly above Normal quantum of rain during June and July.

Thus the blog Vagaries of the Weather estimates Normal progress of the SWM and rainfall in all of sub continent regions!

Further, while weak El Nino conditions are persisting, there is a 50:50 chance, according to Mr Kapadia, of Neutral ENSO conditions as early as July. This would result, continuation of the Monsoon progress, without the normal mid season Monsoon Break!


For the record, while Vagaries of Weather estimates that Monsoon will reach Kerala by 4/5 June, IMD in its press release of May 15, forecasts the date of arrival of Monsoon at Kerala as June 7 +/- 4 days, ie any time between June 3 to June 11! Also the Preliminary forecast of IMD dated April 12, 2016 estimates the quantum this year as above normal (106% of LPA +/-5%).