Is Tamil Nadu heading for poorest Northeast Monsoon in almost 150 years

As we get close to end of November the peak Northeast Monsoon month the current deficit for Tamil Nadu stands at -70%.  Against the normal expected rains of about 33 cms till November 24th the state has recorded only 11 cms so far.  With about 6 days left for November numbers to add up we are potentially looking at the worst Northeast Monsoon performance ever in the last almost 150 years.


As we speak Northeast Monsoon 2016 could be on course to set a couple of unwanted records.  If one sees the chart for the cumulative rainfall of both October & November 1876 has seen the lowest rainfall accumulation so far 12 cms or so.  2016 needs another 2 cms or over the remaining few days of November not to become the worst year for Northeast Monsoon as of 30th November.  Incidentally 1876 is the poorest Northeast Monsoon performance in the last 150 years or so.


If one were to look at the 10 poorest years for the months individually no year has so far featured in this list for both October & November months.  If the remaining days of November does not give us about 12 mm or so we could possibly see for the first time since 1871 a year to feature in the 10 poorest years for both October & November.  To put in perspective the average daily rainfall so far since October 1st has been 1.83 mm and going by model outlooks available we could possibly see 2016 set an unwanted record.


With October & November heading for a wash out how much can December save? Not much probability going by historical rainfall records.  If one were to take the 15 poorest Northeast Monsoon Years as of 30th November only 2 of them have ended the year with above 30 cms rain for the season while 8 have ended between 20 to 30 cms of rains.


While our statistical probability does not offer much hope we could possibly expect Nature to give us the answers and save Northeast Monsoon 2016 from an overall disaster with models showing some increased tropical disturbance activity in the first week of December.