Sunday, January 12, 2014

North East Monsoon 2013 - End of Season Summary

Background
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The 2013 NEM was unique, there was not even a single Easterly Wave which affected TN. All the easterly waves either intensified into Depression or Cyclones in their early stages itself. TN missed most of the systems and so the rains missed us resulting in 2nd consecutive NEM failure for TN. The Two Depression which crossed TN gave rains for only for 1 day.

1st system - Very Severe Cyclone Phailin (Most Powerful)
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The 1st system to form in October was Cyclone Phailin (October 8 to 15) it nearly intensified into Super Cyclone. It went to Orissa/North AP. Tamil Nadu did not get any rainfall from it. Many places in Orissa got close to 500 mm. Technically NEM set in after this Cyclone. The Cyclone killed around 44 people in Orissa. The cyclone 1st made landfall in Mayabunder in Andaman Islands where it pounded 750 mm rainfall in just 3 days.

2nd System - WML in Andhra Pradesh (Dumped record rains and stood like a Rock)
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The second one was a Well Marked Low Pressure Area (WML) (October 20-28). It formed near TN and moved north to AP. This system gave rains to Tamil Nadu for a day or 2. It nearly intensified into a Depression and was a record WML as it lasted around 8-9 days. Andhra got mammoth rains. Kallingapattnam in AP got close to 800 mm. Even Orissa got very Heavy Rains around 200 mm. The Heavy rains killed  around 50 people in AP.

3rd System - Deep Depression or 2013 Somalia cyclone (Caused the most Deaths)
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The third system of NEM 2013 was Deep Depression (November 8-15). It was a Low Pressure in Comrin Sea near Kanyakumari. It gave good rains to Tirunelveli, Ramanathapuram, Kanyakumari and Tuticorin districts as a Low Pressure. Ramanathapuram and Papanasam got around 400 mm first week of November. The low pressure then intensified into a Deep Depression, nearly became a named cyclone and moved away from Indian coast and made landfall in Somalia in Africa and killed over 140 people. Bandarbeyla and Eyl in Somalia got around 350 mm rainfall while their annual rainfall was just 250 mm. It was one of the worst cyclone to hit Somalia.

4th System - Depression (One day show)
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The 4th one was Depression (Novemeber 13-17). Cuddalore, Nagapattinam and even Chennai got good rains (100-200 mm). But it lasted only one day and as it was a Sheared system rains were not so heavy. It travelled from Philippines to TN only to provide only 1 day of rains.

5th System - Severe Cyclone Helen (Surprise of the NEM)
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The 5th system was Cyclone Helen (November 19-23)  No one including IMD expected it to become cyclone, however it became a cyclone. Then all models predicted it to weaken and take a loop and cross north of Chennai. However it strengthened and crossed Central AP. It was again a complete miss to TN. It caused widespread  destruction in Andhra Pradesh. Vishakapattannam and may other places in AP got over 200 mm rains. Rains were also witnessed in Maharashtra. It has to be the surprise Cyclone of this season.

6th System - Very Severe Cyclone Lehar (No rains/winds - a dud)
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The 6th System was Cyclone Lehar (November 23-28). Hopes in TN soared as all models initially showed TN as landfall. But this cyclone intensified and as usual it moved to AP . It completely gave a miss to TN. It weakened in the sea and crossed Central AP as a very weak system. There were no heavy rains nor any winds. It should be called as the dud of the year.

7th System - Very Severe Cyclone Madi (It made a rare U-turn)
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The 7th System was Cyclone Madi (December 1 to 13). As a low pressure, Ramanathapuram, Tutucorin, Tirunelveli and Kanykumari dts got very good rains with some places getting over 100 mm. However this system also intensified and moved north. All intensified system move north as upper level winds were west to east. But this also weakened and came back to TN in Depression strength. Again it gave rains for only 1 day, Kanyakumari and Villipuram dts got good rains (100 mm). It was also a long lasting cyclone.

8th System - Depression (Spillover of NEM into January 2014)
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A break of one month, the Northeast monsoon spilled over into January. It is a common phenomenon. A Depression (January 3-10) formed near Sri Lanka. It gave around 200-250 mm rainfall in Sri Lanka. Then it entered Gulf of Mannar and gave rains to South TN. Papanasam got around 250 mm rainfall. It was a bonus rains to South TN. Even though the rains were from NEM, it counts as winter rainfall for statistical purpose.

Conclusion
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This sums up the NEM 2013. There was no monsoon rains from regular easterly waves nor did any of the low pressure/depression stay in TN for 2-3 days providing rains like the one Low Pressure which gave bounty to AP.  All the rains were associated with cyclonic systems and as most of then intensified early and thereby moving north and giving a miss to TN. As the cyclones move north the regular NE winds got subdued and thereby resulting in failure of NEM to TN. This is the 1st time in the history we had 4 named cyclones between (October - December).

See you in 2014, NEM Success and failures occur together. From 2005-2011, TN had normal NEM, for past 2 years it was a failure. Lets hope 2014 turns out to be different.

1 comment:

Manikandan N said...

good effort

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