Will low turn to an organized system before landfall

All eyes now on 99W.

Very heavy rainfall and some winds for TN on wednesday as system will become better organized near coast. Models expecting this system to be of a minimal one with depression intensity or DD at max.

Interesting part of this forecast is that strongest part of the system is with high winds and bulk of rains to sweep North TN.

Season started with a bang to South TN till date and now will this forecast turn out to fulfill our thirsty N. TN?

Topic Courtesy: Selvan Fun / Vinodh

2,659 thoughts on “Will low turn to an organized system before landfall

  1. THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 7.3N 96.6E,
    IS NOW LOCATED NEAR 8.8N 91.4E, APPROXIMATELY 695 NM EAST-SOUTHEAST
    OF CHENNAI, INDIA. RECENT ANIMATED MULTISPECTRAL SATELLITE IMAGERY
    SHOWS FLARING CONVECTION OVER A CONSOLIDATING LOW-LEVEL CIRCULATION
    CENTER (LLCC) THAT HAS BECOME PARTLY EXPOSED. UPPER-LEVEL ANALYSIS
    REVEALS A MARGINAL ENVIRONMENT WITH DIVERGENT EASTERLY OUTFLOW.
    HOWEVER, MODERATE (15 TO 20 KNOT) EASTERLY VERTICAL WIND SHEAR IS
    DISPLACING THE ASSOCIATED CONVECTION. MAXIMUM SUSTAINED SURFACE WINDS
    ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
    ESTIMATED TO BE NEAR 1006 MB. IN VIEW OF THE MARGINAL UPPER LEVEL
    ENVIRONMENT, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT
    TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW.

  2. The city is likely to experience showers from Wednesday or Thursday.

    Regional Meteorological Centre officials said that a low pressure area in the South Andaman Sea and adjoining areas that could develop into a well-marked low pressure area is expected to bring the showers.

    Tuesday however, will remain dry. An upper air cyclonic circulation over south coastal Andhra Pradesh and West Central Bay is likely to bring rain to some places in the State and Puducherry.

    On Monday, the maximum temperature recorded at Nungambakkam was 32.2 degree Celsius and minimum was 25.5 degree Celsius. The Meenambakkam Met station recorded a maximum of 31.6 degree Celsius and a minimum of 22.8 degree Celsius.

    http://www.thehindu.com/todays-paper/tp-national/tp-tamilnadu/rain-likely-from-wednesday/article6585177.ece

  3. Most worrying factor this news – Hence -the current “Low” must make it “High”

    ————

    May break spell

    The incoming spell of rain is expected to break the lull in the North-East monsoon rains during the last week when even the Tamil Nadu Met subdivision registered a deficit of 54 per cent.
    ==================================
    The deficit is worse with neighbours – 99 per cent in north interior Karnataka; 97 per cent in south interior Karnataka; and 87 per cent in Rayalaseema. Kerala was relatively better off with a deficit of 24 per cent.

    The rest of the country didn’t fare much better either with all-India deficit for the week ending on October 31 at 78 per cent. Even for the season (October 1 to November 5) for which statistics are available, the overall rain figures for the country tossed up a deficit 30 per cent.

    Tamil Nadu provides an exception having recorded excess rainfall of 23 per cent. Kerala was next best with 16 per cent (classified as normal). The rest of peninsula is variously under deficit.
    ============================================
    http://www.thehindubusinessline.com/industry-and-economy/agri-biz/fresh-low-in-andaman-sea-may-not-get-much-traction/article6583086.ece

    • Agree. Rayalaseema and Central Karnataka also depend on NEM rains. Very poor show there. Kavali and Nellore are NEM heavyweaights – how many times have we seen their name in the honor list so far. Hmmm

  4. Its moving towards North Sl and Nagai…its unable to sustain its bands..hope its able to consolidate before it comes to us

  5. Shankar what about the comments posted yesterday night in this topic in the. In domain?
    Has it been deleted or archived there ?

  6. Good morning to everyone.
    Wait for the suspense will get over soon tomorrow.
    Hope we have 2 good solid rain filled days starting from tomorrow night.

  7. Shear is favourable…sst is decent at South Tn coast..need tochk if itcan pick up moisture from the earlier system…D is on thecards

  8. lets see the position of the system at evening..i am having school…
    our day starts form tomorrow…we re predicting this system more than two weeks..
    it should be an well organized system with good winds and very heavy rains while landing and before landing..
    any chance of pull effect?

  9. Let’s see how much it progresses today before the close of the day.
    It is keeping all of us on toes .
    Hopefully it should be able to satisfy us with minimum 300 mm in 2 days time

  10. when rains going to start, is it going to delay because of its strengthening, or it will act as previous one that kept on roaming and finally made a week landing in Andhra, or will it be swift direct crossing?

  11. Navy NRL maintains system intensity at 20 knts. Convection has build over the last few hours. Shear is low and is further expected to remain on a decreasing trend . Upper level divergence is 30, which is currently more than the lower level convergence, which is good for intensification or the least to sustain . Water vapor content shows the convective activity is quite better …..

  12. PJ,

    Replying to your earlier post.

    I know i was late in saying the rains will start from tonight or tomorrow early morning.

    I am totally ZERO during weekends, since no access to net and it is quiet difficult to browse since my son will not allow me to use mobile or either laptop. When he is asleep then i can use it.

    Monday too i was on holiday and i was busy with my personal work, so it is tough to come online.

    When i am in office i can do something.

  13. Enjoi the rain guys from tomorrow..didn’t have time to blog temp -17 ,hectic work and need to cook myself as well in Calgary..Missing Chennai badly

    • Jim Andrews of (ex) Accuweather used to extensively blog about these places. A few years back I read extensively about these places. It seems they have horse meat for food!

    • These sort of questions are very difficult to answer..I mean to forecast the quantum of rains etc..You can only categorise it as light/moderate/heavy/ extreme rains…We got to be patient here..

  14. If you plot the last 2 positions,it shows the direction as heading between Pondy and Chennai.But looking at the system,it seems to be destined for North srilanka/Nagai.Good divergence and a struggling convergence.We need to search for a good Northern Quadrant

  15. According to MJSOI model based on MJO & SOI forecasts, track A and B can be generated.

    (1) Why track B is ruled out in 100%?
    Ans: MJO can not enter phases 4,5 ,6 at least next 7-14 days.

    (2) Why track A will be followed for landfall? Will any follow up easterly waves possible.
    Ans: 99W will follow exactly track A and cross the coast between STN and N-SL at Vedaranyam/Nagapatnam due to MJO’s entry to phase 8, further towards phase 1 during next 2-3 days. Later MJO enter phases 2 & 3 (Indian ocean), which can rigger follow up easterly waves after 99W 🙂

    (3) Why 99W has more northerly oriented cloud band?
    Ans: As wind shear/VWS is oriented north-south direction. expecting this type of wind shear pattern till the landfall. So heavy rainfall can be extended till NTN/SAP.

    (4) Intensity:
    As 99W will come under the partial MJO-SOI coordination, it may stay between WML & D/DD.

    MJSOI-model general diagram: http://s15.postimg.org/fa0j0jagb/Page_1_MJSOI_1_model_05_16_2014.jpg

    MJSOI model’s 99W track prediction:

  16. My Foreca predicting showers from today evening itself..intense TS may develop over interiors as the bands come closer..

  17. Recent tropical weather

    This past week has seen two regions with particularly active tropical convection. A deep low pressure system was active over the Bay of Bengal, and cloudiness in the northwest Pacific Ocean was greater than normal in the wake of typhoon Nuri. Otherwise, tropical convection has been active along much of the equator, as is usual for this time of the year.

    This time of the year is also a period of transition for the monsoon, with the focus of tropical convection moving slowly southwards into the southern hemisphere. The northern Australian monsoon onset usually occurs at Darwin, Australia, in late December; however, this can be later in El Niño years. See below for more information on the current state of El Niño

  18. Madden–Julian Oscillation weak but likely to strengthen

    The Madden–Julian Oscillation (MJO), currently located over the western hemisphere, has remained weak this past week and hence is unlikely to have had a strong influence on recent tropical weather. There is agreement between climate models that the MJO is likely to strengthen over Africa and move slowly eastwards over the Indian Ocean in the next two weeks. There is some variation in how fast the MJO is likely to move across the Indian Ocean, with some models having it enter the Maritime Continent at the end of the fortnight. When the MJO is active over Africa and the Indian Ocean, it typically suppresses convection over South-East Asia and northern Australia, while enhancing convection over the tropical Indian Ocean.

  19. Warm tropical Pacific waters, but ENSO remains neutral

    El Niño–Southern Oscillation (ENSO) indicators and Australian rainfall patterns continue to show some El Niño-like signatures, however, ENSO remains in the neutral range. Sea surface temperatures (SSTs) in the tropical Pacific Ocean have warmed over the past two months, with the latest NINO3.4 SST anomaly at +0.8 °C. The latest Southern Oscillation Index value to 9 November 2014 is −13.2.

  20. LPA forms in Bay of Bengal – Tamil Nadu to get heavy rain from tomorrow morning.
    ======================================
    A Low Pressure Area has been formed in Bay of Bengal. This system may intensify into Depression and not more than that. If it becomes a Depression it may cross the Central TN coast on 13th Morning. Either Depression or LPA, this is a rain filled system big enough to give heavy rains to entire TN. Coastal TN, West TN and South TN will get big numbers.

    On 12-13th Morning Coastal areas will get heavy rains. Right from Chennai till Cuddalore district will get heavy rains. Chennai is expected to get rains entire day tomorrow and better be prepared for the heavy flooding spell.

    When the system moves in between 13-14th morning, Nilgiris heavyweights such as Ketti, Coonoor, Kanyakumari heavy weights such as Pechiparai, Chittar dams, Upper Kodayar, Thiruparappu, Thiruvattar, Theni district, Coimbatore district, Tirunelveli district’s papanasam dam will all also get good rains.

  21. According to MJSOI model based on MJO & SOI forecasts, track A and B can be generated.

    (1) Why track B is ruled out in 100%?
    Ans: MJO can not enter phases 4,5 ,6 at least next 7-14 days.

    (2) Why track A will be followed for landfall? Will any follow up easterly waves possible.
    Ans: 99W will follow exactly track A and cross the coast between STN and N-SL at Vedaranyam/Nagapatnam due to MJO’s entry to phase 8, further towards phase 1 during next 2-3 days. Later MJO enter phases 2 & 3 (Indian ocean), which can rigger follow up easterly waves after 99W 🙂

    (3) Why 99W has more northerly oriented cloud band?
    Ans: As wind shear/VWS is oriented north-south direction. expecting this type of wind shear pattern till the landfall. So heavy rainfall can be extended till NTN/SAP.

    (4) Intensity:
    As 99W will come under the partial MJO-SOI coordination, it may stay between WML & D/DD.

    MJSOI-model general diagram: http://s15.postimg.org/fa0j0jagb/Page_1_MJSOI_1_model_05_16_2014.jpg

    MJSOI model’s 99W track prediction:

    • sorry for the repost.

      I am trying to solve the post-image problem myself. problem stays like that :(.

      This problem doesn’t exist before.

      • I have exactly the same problem here! Not able to post any kind of image by any means, be it copy-paste or upload a photo :/

    • According to MJSOI-model’s general diagram:

      STN/GOM/SL is the only probable area for landfall if MJO stays at present phases 1-2 & SOI oscillates around -5 to -10 (present SOI value around -13.45).

      Need to see how much SOI will gain from -13.45 to get into -5 to -10 limit. According to GFS, SOI forecasted to increase during next 48-72 hrs.

  22. Where is everybody? Rain is around the corner and blog is silent.

    Few changes made to the blog codings, hopefully we will not have issues anymore

  23. New bloggers,

    Southern Oscillation index (SOI) is not a numerical value as everyone thinking. SOI has its own language to influence the frequency and tracks of tropical cyclones.

    There are n-number of references for the frequency of cyclogensis and relation with SOI value.

    Please find the one such reference, which is related to SOI-value and east-pacific hurricanes’ track.

    SOI value and east-pacific hurricanes’ track literature reference:
    http://onlinelibrary.wiley.com/doi/10.1029/1999GL900533/abstract

  24. Wind max. at 20 knots seen in northern regions , MSLP @ 1005 hPa.
    Moving in a WNW direction, shear is still a bit lower , clear indication in the convective activity …

  25. just came out from badminton…very humid today with lot of dragon flies and lot of clouds hovering…Definite rains around the corner..looks like a very fast system…a kind of 2005 oct 27 depression..will it repeat ( asking too much i know)…

  26. I need to go vishakapatnam on 15th november by train from coimbatore. Is there any possibilities of disruption due to mother nature?

  27. Rami,

    It is tough to become a cyclone, since the waters are not warm as it requires nearly 30C or above.

    currently the SST is at 29C around the system, and it is not likely to increase in short time.

    also the ridge is not moving down the latitude in next 2 days.

    • what about MJO’s support? MJO (even Rossby/kelvin) can extend its support from very long distance, especially when there are no other tropical disturbances any where.

      Moreover SOI forecasted to increase after November 1st before again dropping from this weekend.

    • Not really Partha , SST @ 29 C is not less ….Thane formed and was surviving @ 26.5 C , very marginal value .
      They require SST >= 26.5 C

      • Partha , Thane had conditions of SST , almost between 26 C and 28 C in the beginning an later close to 26 and 27 C . For ur Ref.

      • Partha,

        Cyclones are usually believed to form when SST >= 26.5 C , that is the minimum SST required . This is one factor needed among several factors . But systems have even formed at SST lesser than that .
        So we cannot completely say that if SST is below 26.5 C , it is not conducive.
        A lot many factors play a crucial role …

      • Gokul,

        IOD is neutral and BOB SST is around 26.5 oC, then how the moisture comes for intensification, that too in December last week (ridges settle firmly around 5N-7N)???

        Unbelievable if we see the intensity??

  28. Meteorologists have attributed the warmer days to cloudless skies. “It is not unusual to see dry spells in between spells of rain during the northeast monsoon,“ said former India Meteorological Department (IMD) deputy director general Y E A Raj. “Unlike during the southwest monsoon, when hardly a day goes by without a wet spell, the northeast monsoon is usually associated with a more dry weather,” he said. These ‘dry’ periods could last up to seven days at a stretch, with the normal maximum temperature hovering around 30°C.

    Weather blogger Pradeep John said the trend of warm days and cool nights was likely to reverse with a low pressure area brewing over the Andaman sea in Bay of Bengal. “The next spell of shower is heading towards Tamil Nadu and we will see rain by Tuesday night or Wednesday morning,” said John. He said, overcast skies could result in days becoming cooler and nights warmer.

    http://epaperbeta.timesofindia.com/Article.aspx?eid=31807&articlexml=As-city-awaits-rain-nights-turn-cool-11112014003034

    Two things to be noted in the above TOI newspaper link today. One is as usual our blogger friend Pradeep John gets mention.
    Second the first paragraph of the post content answers or explains NEM rain phenomenon with breaks in between by Dr. YEA Raj (Retd IMD) where in he has compared SWM rains and NEM rains..a week back i had posted about how a city like Bombay fares during SWM even if there is a break in monsoon period..You hardly get to see a clear blue sky days during SWM rain break period and one tends to see at least some passing showers with some cloud cover there almost on a daily basis…This is not the case here and most of us tend to lose patience and and look for the next spell with lot of anxiety..Susa in fact had posted a nice compilation of NEM rainfall pattern with how the city gets rains in divided spells with good breaks in between..Expecting daily rains during NEM thus is not fair as our rain season follows a pattern.

  29. alert…

    99W will travel all the way in perfect westward direction till the coast.

    Slight intensification will make little NW-track just before landfall.

    • Are you kidding me? Not bad?? That’s awesome! Like atleast 26C SSt is needed for cyclone formation, 28 is the prerequisite for severe cyclones

  30. One more reason is why 99W will not become cyclone, the upper level winds are weaker and discontinued, at around 10 knots and goind to be weaker for next 4 days. This is also another reason.

    If it becomes cyclone, the big advantage is that the mid level ACC is over north bay and the movement of dry is from east to west till 14N, hence the system will move towards Central TN, but the conditions are not favourable.

    The Ridge and Upper Level Winds are the villains at the moment.

  31. RS Rao,

    For the case of Thane , not only SST was low, but even TCHP was below the conventional value.
    We cannot conclude using one or two factors like IOD value or any other factor etc..

    • Exactly gts.. thane enjoyed very favorable shear but sst was around 26.5 to 27.. tchp value was around 20 but still managed to survive n sustain it’s intensity.

    • SOI played dramatic role in combination with MJO (phase 5, maritime continent with amplitude 1.5-2)

      SOI is abnormally very high (+23.0) at pre-thane days in December.

      MJO & SOI favorable conditions made Thane-2011 as a furious cyclone even when IOD, SST, TCHP are unfavorable. This type of cyclones for TN, that too in December last week are very very rare.

      November 1st: +13.8
      December 1st +23.0
      January 1st +9.4

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