Wednesday, May 12, 2010

7pm, New thunder cells over S. Karnataka, W-central Tamilnadu ..
6pm, Showers over Tirunelveli district in Tamilnadu again, While showers over S Kerala continues..
Highest rainfall in South India -- discussion !! ...
Early monsoon onset over Kerala likely (around 22-May)..

Early monsoon onset over Kerala likely

Onset of South-West monsoon over the Kerala coast may not take place until May 21, but can follow immediately thereafter, according to latest estimates.

The prognosis for the two branches — Arabian Sea and Bay of Bengal — suggests that the monsoon would ride the ongoing wet phase of the Madden-Julian Oscillation (MJO) wave to make an early onset this year.


The MJO wave travels periodically from west to east in the higher levels of atmosphere and has alternating ‘dry' and ‘wet' phases setting up rains or dry conditions as the case may be.

Though confined to the higher levels of the atmosphere, the MJO wave has a significant bearing on monsoon flow dynamics at the lower levels, variously setting up onsets, low-pressure areas and even cyclones. At the other end of the scale, the ‘dry' phase of the MJO wave is blamed for the intra-season rain shutouts and incidental ‘break monsoon' phases.

According to Dr Akhilesh Gupta, leading operational forecaster and Adviser to Department of Science and Technology, this time, the onset over Andaman and Nicobar Islands, Sri Lanka and Kerala would happen within days of each other.

As per early analysis, it is likely that the onset would happen over the Bay Islands around May 18, which would be followed close on the heels (within the next two days) over Sri Lanka.

The build-up is such that this should lead to the eagerly awaited ‘burst' over the Kerala coast almost immediately thereafter but Dr Gupta finds that the amplification of the flow pattern and moisture carry mostly confined to below the 10 deg Latitude.

Thus, the activity is seen to be concentrated over a stretch of seawaters between Arabian Sea and the Bay of Bengal (referred to as ‘Indian Sea') during this phase.

The Arabian Sea arm of monsoon may have been seen having an ‘edge' until now, but the Bay arm is catching up fast backed up by strong southerly flows to precipitate onset over the Andaman Islands in the usual time band.

The causative wet phase of the MJO wave, though, is shown by various models as exiting the Indian region even as the monsoon flows get into the groove (around May 19) and much before the onset over mainland India.

This is because, after the flows entrench themselves, the monsoon would be able to flourish on its own without the MJO prop to advance further into the mainland.

The next wet phase would not set in until June 15, according to the outlook by the Empirical Wave Propagation model employed by the Climate Prediction Centre of the US National Weather Services. A strong monsoon ‘pulse' could be expected to be triggered along with this.

Before this can happen, both Arabian Sea and Bay of Bengal are likely to witness the genesis of west-to-east oriented weather systems around May 25. According to Prof Paul Roundy, a renowned ocean weather forecaster based in the US, the Arabian Sea system may head towards the west coast.

By the same token, the Bay system, though weaker in strength, may hurtle itself towards the West Bengal and adjoining Bangladesh coasts.

Rainfall data from 1-Jan-2010 to 11-May-2010

India toppers from 1.1.10 to 11.5.2010
Cherrapunji 374 cm
Passighat 115 cm
Silchar 101 cm
Dibrugarh 83 cm
Itanagar 83 cm
Gangtok 78 cm
North Lakhimpur 65 cm
Dhubri 59 cm
Guwahati 58 cm

TN toppers from 1.1.10 to 11.5.10
Pechiparai – 39 cm
Kodaikanal – 29 cm
Andipatti – 27 cm
Thalli – 27 cm
Kuzhithurai – 26 cm
Boothapandi – 25 cm
Valparai – 25 cm

compiled by Pradeep

Highest rainfall in South India -- discussion !!

Dear Pradeep,
Chinna Kallar [Coimbatore District] and Devala [The Nilgiri District]gets its maximum rainfall during SW monsoon period only. This time, as has been predicted earlier there will be lesser amount of rainfall during SW monsoon period in the western sides of western ghat where Chinna Kallar and Devala are located. This is an indication. Your pre- monsoon (up to 7.5.2010) study somewhat depicted rainfall pattern especially during SW monsoon period. However Kanyakumari district is also known for its copious rainfall. The western side of the district will easily get more than 1500mm annual rainfall. Some of the locations in the hills like Upper Kothaiyar, Balamore etc are getting rainfall greater than 2500mm [upper Kothaiyar still gets more rainfall ranging to 3500mm] However upper Kothaiyar has to be accessed by road from Ambasamudram only.
Hence Chinna Kallar or Devala overtaking the toppers before May end is LESS probable only.

Posted by Ponnachi G Son

Thanks for ur views - i am from place near gets good rain in may......!

Which is the rainiest place in Tamilnadu

i have seen ur blog it says

Upper Nirar Dam is the Rainiest place in the region

wat abt CHINNAKALLAR u have year data of all the places u have discussed..can u share with us...i dont think chinnakallar's SWM rainfall to be 2975mm....whats its annual rainfall....!

posted by Pradeep

Chinnakallar (Upper Nirar) recorded the highest of 366 mm rainfall

Upper Nirar i.e., Chinna Kallar recorded the highest rainfall of 423 mm

Chinnakallar-91, Upper Nirar-91

both Upper Nirar & Chinna Kallar
are same...according to IMD

posted by Pradeep
3:30pm, new thunder cells over S. kerala ..
3pm, Band of Showers over Orissa are getting bigger..
Media Workshop on “Communicating Weather & Climate Information” ...
Eclipse Tour 2010 - Easter Island on 11-Jul-2010 ...
@HelloFM1064 >> It'll touch 42 before 23-May-2010.
Thundersqualls would occur over J&K, H.P, Uttrakhand, Bihar, Jharkhand, Bengal & Sikkim, N-E States, Orissa, Karnataka and Kerala in 48 hrs
Increase in maximum temperatures by 1-2°C is likely over plains of northwest and central India during next 2-3 days
Heat wave conditions are prevailing over pockets of Rajasthan, Gujarat, Madhya Pradesh, Vidarbha, Marathawada, A.P, Chhattisgarh and Orissa.
On 11-May, highest maximum temperature of 46.6°C has been recorded at Chandrapur (Maharashtra).
Rain map of 11-May:: ..
Rain on 11-May, Cherrapunji-17, Passighat-9, North Lakhimpur, Kailasahar-4, Itanagar, Dibrugarh, Mangalore-3 cm..
IMD event :: WORKSHOP WITH MEDIA ON MAY 14,2010 ..

Media Workshop on “Communicating Weather & Climate Information”

You are very well aware that one of the primary mandates of National Meteorological Services worldwide is to provide reliable and accurate weather information and warnings to the public to ensure the safety of life and property. India Meteorological Department provides daily weather information and forecasts from it’s Headquarters at New Delhi and from other forecasting centres in all the States.
Electronic and print media is playing an important role not only in disseminating the weather forecasts and warnings to every nook and corner of the country but also in making these understood by the common man and also in providing us feedback. However, in view of advent of large number of TV channels and Daily News papers, it is felt necessary to escalate the interaction between IMD and mass media to mutually understand the requirements of each other.
IMD is therefore, organising one day media workshop on “communicating weather and climate information” exclusively for electronic and print media on 14 May, 2010 at India Islamic Cultural Centre, Lodi Road New Delhi. Hon’ble Minister for Science & Technology and Earth Sciences has kindly consented to grace the valedictory function as chief guest. The workshop will provide opportunity to the media people to interact with eminent scientists in the field of weather and climate forecasts.

In this regard, all the media groups operating from National Capital Region of Delhi are requested to kindly depute a suitable nominee (who is associated with production/ presentation of weather capsules etc.) to attend the workshop as a delegate and send the contact details latest by 10th May 2010 for making prior arrangements.

posted by Anonymous
Chennai - According to BBC, Chennai will not touch 40 deg C till this weekend..max will be around 39 deg C.
1:30pm, Thunder cells popping up over central Orissa and N-central Andhra.
Good sign for S-W Monsoon :: Very good cross equatorial winds forming in the Arabian Sea
Chennai - past 3 year Summer temp. record..
2008 – 42.1
2009 – 41.1
2010, May 11 – 39.3 (till date)
Hot day for Delhi ...
10 new automatic weather stations by year-end: IMD ..
Clear & Hot looking India so far at 12:30pm..
Chennai - Will touch 40 today or tomorrow.