Pondicherry - 15-Jun, late evening heavy showers

It ir raining heavily in pondy since 9pm (15-Jun). Previously heavy wind from SW from 7pm to 7:30 and rained heavily from 7:30 to 8pm. Now pondy is like kerala(very cool).


Rain stopped now (1:44am). I think another12cms for pondy. This time it will not be on top of the table. power cut for 3.5hrs due to wind and lightning. 


As reported by Dhinagar

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 Pechiparai....it 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

http://www.hinduonnet.com/thehindu/thscrip/print.pl?file=2007070358020300.htm&date=2007/07/03/&prd=th&

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

http://www.hinduonnet.com/thehindu/thscrip/print.pl?file=2007062461310300.htm&date=2007/06/24/&prd=th&

Chinnakallar-91, Upper Nirar-91

http://www.hinduonnet.com/thehindu/thscrip/print.pl?file=2007062556370300.htm&date=2007/06/25/&prd=th&

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

posted by Pradeep

A comment on "Monsoon Watch"

Monsoon watch is one of the component of weather watch. You may watch it from Mumbai. Some may watch it from Karnataka and even some may from Mauritius {I am referring to Indian Summer monsoon only] However it is an interesting study. During the month of May generally Bay will be active with transitional pressure, repeat pressure pattern. Winds, accordingly vary in Bay. Recent developments show the wind discontinutity is prominent from Bihar to Tamilnadu coast via Jarkand, Orissa and AP. This underlies one thing that this year SW monsoon will be faily good in the eastern side of Western ghats. Western side of Western ghat may not be as good as to its eastern counterparts. Sometime Mumbai may be getting lesser rain too.

South west Monsoon forecasting ...!!

IMD's long range forecast has only one thing of interest, that is its prediction that this year its going to be 98% of long term average. But it does not specify which regions would get more rain and which regions would get less. As 98% would be a country wide weighted mean; and india is a big counry, there's still a possibility of some part/parts having droughts/less rain.
IMD should improve its forecast, make it more informative and make it more interactive. I see some room for improvement in these quarters. And one more thing: Why isn't IMD including weather data and readings from regions and countries like Pakistan, Nepal, Bhutan, Tibet,Bangladesh,Burma and Srilanka. My guess is, the readings from these regions/countries would definitely play a crucial in monsoon forecasting. Monsoon is regional phenomenon and monsoon winds do not recognize political boundaries.I am sure the premonsson conditions in pakistan and tibet plays as important role in monsoon generation process.
Posted by Mr. Neeraj
------------------------------------------------
SAARC nations comprises India, Pakistan, Bangaladesh, Nepal, Myanmar, Bhutan and Srilanka and there is co operation on weather among SAARC nations.
Though Monsoon is regional, it spreads further into Asia up to China. That why it is known as Asian Summer Monsoon.
But contrary to your belief, the [SW]monsoon winds originate from SOUTHERN HEMISPHERE near 30 Deg South and 60 Deg East in south INDIAN OCEAN.(Say, near Mauritius)
[1] The Southern Hemisphere MASCERENE HIGH plays a crucial role in determining Asian Summer Monsoon winds.
[2] The position of this HIGH pressure depends upon ENSO
[3] Further ENSO has its influence of the Sea surface Temperatures in Eastern Pacific i.e East of 180 East International Date Line.
[4] The land heating (or the heat low)in Jacobabath in Pakistan
[5] The Sub Tropical Westerly Jet zonal flow & the Sub Tropical High [STH] position over Himalayas and Tibet etc. etc also matters. These climatological factors are also taken in to consideration along with major predictors. But their influence may be in lesser scales than compared to the influence of Masceren High, SOI and other major predictors.
Region specific LRF can be tried or attempted provided the local climatological influence is properly understood or accounted and ensemble evolved accordingly.
In our country other agencies lick C-DAC, Center for atmospheric Sciences [IISc], SAC and few Agricultural Universities including TNAU are releasing advance forecast about monsoon RAINFALL. More or less some of them are regional specific.

posted by Mr. Anonymous
------------------------------------------
@anonymous:
Myanmar is not a SAARC member but Afghanistan is. And yes, i do have some knowledge about where SW monsoon starts. I was just pointing out to the fact that Pakistan and Tibet also plays a role and i feel that these things are not given due importance. Overall prediction of course depends on the important factors that you have pointed out. But other factors will surely help to fine tune the whole thing. And yes, though Burma and China are not in SAARC, i again like to point out that SW Monsoon does not recognize any boundaries.
And on another note, all the countries in this region and particularly those in SAARC should cooperate much more as the economy and livelihood of the people in these regions depend on SW Monsoon.Maybe India can provide some assistance in weather data collection in SAARC countries.
Posted by Mr. Neeraj

Is it appropriate to call as Easterlies as this time of year ??

Is appropriate to term it EASTERLY wave during pre monsoon period. Even though the winds up to certain level be easterly i do not think it producing a wave. Any how it can be termed as weak easterlies.
To day 03.04.2010 /2113 hrs IST Kerala coast and SIK will be experiencing rainfall.
We in TN will also get rain very soon, once the flare up medium to low clouds in the Bay touches coast. Lower winds are predominantly southerly to SEly where as the upper winds are SWly.

posted by Mr. Anonymous (created on 3-Apr-10)

About the present activity in SW Bay..!!! ???

Refer weather in SW Bay near Srilanka. Some say it is due to early transitional of wind to SW. Some fear that it is a part of MJO i.e system or cloud mass moving predominately towards EAST. MJO may be considered as global phenomenal occurring especially in Indian Ocean and Pacific. There were instances where MJO has given copious unseasonal rainfall in the California region in US. Similarly it may give [sometimes in February]copious rainfall in TN also.

Posted by Mr. Anonymous

"Agumbe may be wet, but Hulikal is wetter" ... Mr.Anonymous responds.!!

For the interest of the general Public I must give certain points on how rainfall is measured. First of all according to WMO criteria
[1] There should be atleast one raingauge in every 250 Sq.Km area in plains and at least one raingauge for every 100 sq.km area in hilly areas.
[2] In India Fibre Glass Reinforced Polyester (FRP) Raingauge of diameter 159.6 mm and collector area 200 sq.cm is in use for the measurements of rainfall.
[3] This 200 sq.cm collector area raingauge must have relevant 20mm measure glass.
[4] Rainfall measurements should have to be taken at 0300Z [0830 hrs IST] daily without fail to enable comparison.
[5] The exposure of raingauge must be good.
Most of the raingauges maintained at vantage meteorological locations are NOT maintained by IMD. State government is maintaining such raingauges. Often the raingauge and measure glass combination may NOT be correct. Thus will lead to distorted or enhanced rainfall amount. {As happened in Chinna Kallar in 2007 ; in that year the annual rainfall was reported as 7000 mm because of the irrelevant measure glass.} In Agumbe too there were instances when the measurements were reported wrong.
In the light of the above I wish to state that Meteorologically vantage location should be properly assessed by scientific community and wish that Government should come out with rigid plans to deploy men and material at vantage locations to augment Disaster Management.

About Bangalore

sset has left a new comment on your post "Temperature in Mumbai has dropped over the century...":

On opposite side, Bangalore has recorded 2-3 degrees increase in temperature. This is due to removal of all trees, lakes and water bodies disappearance. Huge growth in population, huge buildings coming up, massive growth of city, lack of rain is making Bangalore worst city. It should be noted city ranks high on pollution as city has largest number of vehicles.

Another education from Mr.Anonymous

About Minimum temperature
Minimum Temperature will occur half an hour just after Sun rise. The temperature recorded at 0611 hrs IST of date 18.12.2009 may be the minimum temperature. However the other temperature noted [26.6] may NOT be the temperature of that given time. It may be around 21.6.
Coming up ..
Further the rise in pressure and the upper wind pattern also gives an impression that there may cloud formation at SE bay [90-95 Deg East]and at Comrin sea. The "Condensation Trail" [COLTRA]seen at 10000-15000 feet above ground level [flight level 100 and 150]also gives impression that there may be wet weather within another 48 hours of time from now.

How can I post weather imagery in this colomn.??

Anonymous said...
Hoe can I post weathe imagery in this coloumn.

9:31 PM


WeatherMan said...
Yes, anyone can post anything related to "weather, climate and environment".
All you have to do is just mail your post to contact@indianweatherman.com
after moderation we'll approve and post it in www.indianweatherman.com
Depending on your involvement and quality, you'll be given a CO-AUTHOR status. After that you can post directly.

Thanks
Weatherman.

Why cyclones weaken over sea??

sset said...
What caused/causes cyclone to loose steam? Is it due to (a)opposing westerlies? (b)unfavorable sea temperatures? (c)lack of trees/deforestation/global warming? (d) Can this be reversed just like man can induce rain using seeding, weak cyclone can be forced to make landfall into water starved Tamil Nadu? It is quite interesting to note that all weather models predicted vigorous rains for TN during December (EL NINO, wet MOJO) but nature seems to defy all predictions. Last year we had cyclone NISHA, which provided strong rain for TN, but this year TN missed 2 cyclones - ALIYA and WARD. What explanation can be given for above?

7:16 PM
Anonymous said...
Dear isszet,
[1] As such the upper westerlies will not hamper (much) the growth of a cyclone, instead it will make it to recurve in NEly direction.
[2] Unfavourable sea surface temperature may be one of the reasons that it loses its moisture flux.
[3] Deforestation or felling of trees - NOTHING to do with the formation development of a cyclone.
However one must be bit cautious in answering global warming.
[4] Weather Modification has not been attempted any where in the world: that too on cyclones. Technology has not so much developed to capture a desired weather modification.
If we ruthlessly rupture the weather then it will become a WEAPON OF MASS DESTRUCTION [WMD].
[5]Tropical weather is too tricky to be accureately modeled. However this will be over come very soon.

9:27 PM

Comment on -- "India to deploy more Doppler radars"

Anonymous has left a new comment on your post "India to deploy more Doppler radars for weather fo...":

ISRO has already identified and selected sites in cosultation with Agricultural universities of southern states and installed AWS. Agrometeorological units of state Agricultural Universities disseminate daily [local] forcast in collabaration with IMD. [Ref:www.imd.gov.in]But ISRO installing Dopplar Weather Radar [DWR] is a new information; That too at Cherapunji the world's wettest place. If it is true ISRO must consider installing DWR at Kanyakumari, Chinna Kallar,and other meteorological vantage locations in the west.
Note that there is NO DWR in the west coast.
However, by instaling DWR at high mountain ranges, there is every possibilities that the signals will be reflected by mountain range. But I do not know the principles of DWR. I believe that installing DWR at KANYAKUMARI will definetely help understand the South West monsoon and the study of winds and other weather pattern in Indian Ocean.

Comments & Reply on 3-Dec-09

Anonymous has left a new comment on your post "Chennai - Egmore zone recorded only 5.6 mm from 12...": 3-Dec-09


I do not know from where weatherman get [Chennai Egmore] rainfall?
[Egmore reported nearly 2.2cm rainfall ending 0830 hrs IST of 03.12.2009.
"Egmore zone recorded 5.6 mm of Rain from 12 AM midnight of 3-Dec-09,  this DATA is not for 24 hrs"

Today fairly widespread rainfall is realised through out TN. Papanasam [Nellai District] reported 10 cm. The High pressure system located in NW part of INDIA and perhaps it enable easterlies to penetrate in lands of TN even Dhamapuri district. But still Vellore is not getting sufficient rainfall.[Deficient]

Dispatch of cloud mass through Easterlies, slightly above 5 Deg Latitude from South China sea to East Coast of India will last for another week or so.

comments and comments .. getting Hot

Dear SSET,
Have you ever compared this year TN rainfall with TN NEM normal rainfall. For your information upto 29.11.2009 TN has received 10% above NORMAL rainfall for this NEM season. That too the rainfall is wide spread baring few NW interior districts.
EL NINO Southern Oscillation [ENSO] is one of tele- connections our NEM is having. Some times it is very prominent; some time its in significant. There is no reduction in the number of rainy days for TN. But upper air at 925 hPa to 850 hPa level is relatively warmer in most part of the year.This anomaly is to be studied.
Further I will let you know in appropriate time when bad weather related to this phenomenon is occurring.

---------- More about coming up showers --------------
NE winds brought rain in many parts of Tiruvarur district and selected coastal locations in Nagai, Ramanad, and Pudukottai districts. [29.11.2009/0830 hrs IST].
Now NE winds of the order 10 to 15 knots are blowing from NE direction from surface to 850 hPa. This may bring smaller showers to day in Puducherry, coastal Villupuram and Kanchipuram districts. However the High pressure hovered over central India at 850 hPa is prohibiting clouds developments
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Some Reader comments...

Anonymous has left a new comment on your post "COLA-GFS model still holds to the WET december 1st...":

One among the veterans of COLA site is an INDIAN who, sometime back worked for INDIA [IMD]. IITM site like MOL will give more informative and useful data. Models made a digital divide among [young / old] meteorologists and Numerical Weather Predication [NWP]is going to rule future.Youngs have digital capacity where as the olds are of experience. There should be a proper mix.
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sset has left a new comment on your post "Informative Sweet little reader comments":

No we are not blaming Tamil Nadu. ElNino is not bringing vigorous NE monsoon. Why is it so? Generally it is observed that south india is becoming more and more dry with less rainy days. Take example of Bangalore it is extremely hot and temperature touches 39-40 degrees in summer, we don't see any rains here. But places like Maharashtra, Gujarat are receiving extremely good rains (5-6 months) of rain.