Thunderstorm Season Notches up a Gear in Tamil Nadu

Though Chennai missed out on rains as expected by us yesterday many parts of Tamil Nadu got good rains with some places in the Delta Districts, Ariyalur, Perambalur, Tiruvannamalai & Cuddalore districts getting moderate to heavy thunderstorms yesterday.

Two particular highlights need to be mentioned, the first one being Coimbatore AP which got 48 mm all of it fell between 5:30 PM and 8:30 PM.  While the other being Adirampattinam which got about 10 cms in two hours between 9:30 to 11:30 PM in a spell of intense thunderstorms that lashed the delta and surrounding areas like Ariyalur & Perambalur districts.

The thunderstorm season flexed its muscles yesterday and is expected to notch up another gear today in anticipation of what could be the defining spell of August in the next couple of days.  Today also we are likely to see fairly widespread rains at many parts of Tamil Nadu with possibly North Interior Tamil Nadu and parts of North Coastal Tamil Nadu between Pondicherry and Chennai favorably placed for some heavy duty action.  Hopefully with some luck and clearer skies during the day Chennai could join the party as well.  Keeping fingers crossed.

  • New Post UPdated http://wp.me/p6Y3od-1wY

  • aman @ Guduvanchery

    Good clear morning here, and rains will continue for TN and South India, some places in interior TN will show very huge numbers today. For Chennai late night rains possible.

  • SrikanthK
  • SrikanthK

    STorms have stayed in the same place for more than an hour

  • Malakrishnasamy

    Good morning.
    happy to know that widespread rain happened.

    • Malakrishnasamy

      Nilgiris erode Salem dharmapuri districts had negative departure before yesterday’s rain. Hope it had improved todays chart.

      • SrikanthK

        Nilgiris has got some rains, Salem got very good rains, parts of Dharmapuri got some decent rains, not sure of Erode

        • Malakrishnasamy

          Yes anna. Me too not sure about erode data. But rain happening in batches not widespread..

  • SrikanthK

    Today after the morning spell we should keep our expectations low

    • Leo Michaelraj

      Is the storms moving away from us like yesterday

      • SrikanthK

        Yes they are moving ENE I think

    • gargara

      Today actually forecast for heavy rains from one of the models that I follow for areas west of Chennai. So 50-50 if they could move in later today.

      • SrikanthK

        Purely from what I have observed, not checked the charts yet

        • gargara

          So how come these storms are not influenced by day time heating ? Clearly several categories of storms to be studied and analyzed.

          • SrikanthK

            Agreed, the storms over Rayalaseema were expected to happen last evening but happened around midnight.

            • gargara

              Instability conditions in interiors have sustaining power than over coastal areas. Coastal areas appear to be dissipating instability easily. Thoughts ?

  • SrikanthK

    Tiruvannamalai 74 mm

    • Leo Michaelraj

      Here only moderate rains

  • SrikanthK

    North of Chennai must be seeing cloud burst conditions

    • Leo Michaelraj

      Yesterday evening also they got good rains

      • gargara

        Tirupati Renigunta as well.

        • Leo Michaelraj

          Yes SAP also getting good rains. But Chennai…,

  • Leo Michaelraj

    How the storms are moving

  • Yaamesh

    Raining for about 10 mins in Avadi… A bit heavy now

    • SrikanthK

      HVF has got about 25 mm

      • Yaamesh

        Sooper…Still heavy

  • SrikanthK

    Look at Rayalaseema

  • SrikanthK

    Super intense storms near Chennai

    • Ajith Kumar K

      Will that reach porur?

      • Ajith Kumar K

        Good some moderate rains

  • Vivek

    Finally East BANGALORE is getting its share.Steady showers for 15mins

  • Mani Manivannan P

    Good rain receiving in tiruvannamalai.

  • Vivek

    Coimbatore district is slowly turning into an arid region.I can understand Tamilnadu is on the leeward side of western ghats but despite being located on the Palakkad Gap why the SW monsoon winds are not showing any mercy to this region ?

  • Siddhart

    Most models predict rains for Chennai from 2.30am -4.30 am and conditions are favourable. Pop ups finally near yelagiri. Hope reaches us!!

  • Siddhart

    certainly some convergence around tiruvannamalai..chennai’s faith !!!!

  • Siddhart

    could we see a repeat of monday’s unexpected thriller…decision can be made around 11.15pm..

    • SrikanthK

      You can never rule out

      • rohit n

        yes, i feel the same way

    • Siddhart

      yes afterall nothing can be expected how in the next 15 minutes storm’s going to be!!!

    • ~Prince~

      May be no surprise if it move towards Chennai but it should not fade away when entering Chennai !!!!!

      • Siddhart

        lets hope we are lucky.BY GOD’S GRACE!!!

      • rohit n

        true, as of now no sign of weakening ..let’s keep our fingers crossed when it comes within 50 kms from chennai

  • rohit n

    storm near tindivanam …

    • Siddhart

      it is not going to bloom.going to sea…

    • Siddhart

      in and around cheyyar could receive some showers!!!!

  • SrikanthK

    Slow movement order of the day

  • rohit n

    once again like a couple of days back an intense storm near cudallore has been having a northward movement for a while now

    • rohit n

      let’s not keep our hopes high …would be a miracle if it hits chennai

      • SrikanthK

        This may not reach us. Look our for the KRG one

        • rohit n

          i’ve been watching that too…not a lot of movement from it

    • ~Prince~

      Storms moving NE !!!

      • rohit n

        yes…mostly will hit cudallore

        • ~Prince~

          Lets see if storms forms around TVM or not !!!!

  • SrikanthK

    Puzhal has got 53 mm from the evening spells

    • gargara

      We discuss these days offline but maybe you should let people know of the significance of using better models that do incorporate accurate land use and how it influences atmospheric flows.

      Why Puzhal got rain and Nungambakkam or Adyar did not etc

      • SrikanthK

        I think it’s time to have an offline platform as well so that we can share some of the thoughts for better understanding. Once people understand the concepts they can relate future events better

        • What kind of a offline platform do you have in mind?

    • Mani Manivannan P

      Sir, Tiruvannamalai rain ?

  • SrikanthK

    Yercaud ISRO showing 123 mm

  • SrikanthK

    Another rocking day at Delta

    • Mani Manivannan P

      Sir, tiruvannamalai district rain??

      • SrikanthK

        Some storms near Krishnagiri could head your way

      • Mani Manivannan P

        Thank u sir

  • gargara

    http://satellite.imd.gov.in/img/Chennai.gif

    So this is 6.30 pm IST and if people ask why this sounding means no rain or bonus for Chennai.

    In simple words if you ignore the English words and numbers on the right hand side what you are looking at is a rather stable atmosphere.

    You want the green line to be farther away from the blue line with open circles and if the green line can get closer to one of the red lines that would be the best case scenario. Right now that is not happening.

  • Selvakumar(Raijin)

    Going to end up as another great day in terms of rainfall for interiors https://uploads.disquscdn.com/images/3e5d33d7e9a3a4eb963fb8fd6ac043b7a88ebf083c82d1964ebf108ab96d0c54.png

    • Selvakumar(Raijin)

      Coastal delta is in line for rains from interior thunderstorms

  • rohit n

    another day of disappointment for chennaities ..with almost all parts of tamil nadu receiving widespread rainfall chennai has not received anything other than few passing showers ! hope it’s the last day of unluckiness for us

    • SrikanthK

      Let’s wait till Friday that’s when things change for us

  • SrikanthK

    All action happening around Salem / TV Malai

  • Anjur Viswanathan Subramanian

    Chennai has been unlucky for the last few days, something is not working out at the last moment, can’t figure out …

    • gargara

      SWM rains are a bonus for Chennai which is usually gets NEM rains from Oct thru Dec. Interiors are getting better moisture flux and instability in westerlies because of closer proximity to West coast.

      • Venkit PS

        Hello Mr , personally it is the bonus that makes my life much much more fruitful than monthly salary. So what I want is bonus. Salary will anyway come.

        On a side note, I am an illeterate weather blogger. I would please request you to write in terms of my level or illeterate level so that everyone understand things. But overall you are doing a good job.

        • gargara

          Thanks for your vote of confidence. I understand your feelings about bonus and salary. But when dealing with the atmosphere everything is a bonus. There is no salary as such. Ask not and thou shall definitely get

          Regarding level of understanding things -Everyone has to start off somewhere. I told Ajith Kumar the other day that if you learn meteorology as a separate science then it is very hard. However if you learn by associating it with simple phenomena you learned as a kid then it is easy.

          These days I talk a about dew point but you can do some simple experiments at home to see what it is . And others stuff like vortices which can be created at home. Then meteorology will surely lighten up easily.

          • Venkit PS

            I would then think why not you join IMD Sir. We need capable people like you to make the “so called” announcements that will be 100% true. Please think about it.I am still looking at my Bonus as my salary will anyway come.

            • gargara

              I have already had training as a scientist in India and abroad in a field similar to atmospheric science. Joining IMD well I am not sure I would be the right person for that. I grew up in the private sector and I would like to remain there.
              But you don’t hesitate to let me know when I am being obtuse in any thing I say and I will spend the cycle of time to explain the idea to you.

      • Anjur Viswanathan Subramanian

        Hopefully, we get some decent rains to increase the water table levels and also fill up the reservoirs adequately

        Goverment helping public is a good day dream and only nature should help us..

  • Selvakumar(Raijin)
  • Siddhart

    Today most likely there won’t be rains in night for Chennai.Cuddalore pondicherry chances for storms!!!

  • SrikanthK

    Wanted to catch some storms from above on my way to Hyderabad but things looks dull

    • mahamood ali

      Storm Taken a Awkward Diversion , Heart Breaking one 😛

      • narayanan_ky

        If you are tracking chennai storms you will get many such heartbreaks and at times it can give rains when you least expected too…!!

        • Ajith Kumar K

          That’s the unique nature of Chennai unexpected happens sometimes😂

      • SrikanthK

        Arasiyalla ithellam saatheanamappa

  • SrikanthK

    Salem district getting very heavy rains

  • ~Prince~

    New Cell formed in West !!!!

  • ~Prince~

    Storms seem to move North or northeast according to VVP(V)

    • Leo Michaelraj

      So moving away from us

    • ~Prince~

      Very cool winds from North

  • Leo Michaelraj
    • SrikanthK

      Not like North of north Chennai

      • Leo Michaelraj

        Areas around Redhillls and Tamaraipakkam

    • rohit n

      lucky people

  • SrikanthK

    Going away from us possibly

    • Ajith Kumar K

      Being a Spectator last few days nothing in Porur

    • Karthik Bhatt

      Mylapore is bone dry! In fact sky has brightened

      • SrikanthK

        Yes nothing happened in the city area the storm never moved inside Chennai district boundary

        • Karthik Bhatt

          Chances later tonight?

          • SrikanthK

            Models indicate some late night activity but strangely Rayalaseema seems quiet

            • ~Prince~

              Storms can reach from SW also???

              • SrikanthK

                Yes to the storms are strong they may move on their own

  • ~Prince~

    Storm is growing !!!! Getting big

    • ~Prince~

      Now Clouds moving more North to south

      • mahamood ali

        Yup it growing and make it as a Ball

  • rohit n

    Still not much movement from the storm…

  • narayanan_ky

    Wunderground prediction:
    Expect occasional thunderstorms to continue for the next several hours. Enjoy!!
    Thunderstorm chances has become 80 to 90% all over chennai and suburbs.

  • Leo Michaelraj

    Heavy rains here now

    • mahamood ali

      So the storms are moving

      • rohit n

        The actual storm is still stationary.. Some tiny intense pop ups forming around it

        • SrikanthK

          Basically around the edges new cells are forming

          • rohit n

            Would be interesting if it starts moving SE

          • mahamood ali

            Got it Sri

    • narayanan_ky

      which place is leo from?

      • SrikanthK

        Ayanawaram

        • narayanan_ky

          Thanks.
          So today Avadi to kilpauk has got some spells now..

  • SrikanthK

    The storms are just staying in the same place

  • rohit n

    Anna nagar getting battered right now…. Heavy downpour

    • Leo Michaelraj

      But here no rains

  • SrikanthK
    • Leo Michaelraj

      How the storms moving

      • SrikanthK

        Unable to see regularly to understand clearly

  • rohit n

    The imd site has been very poor today in updating radar images.. Wonder what’s wrong

    • narayanan_ky

      yeah we are unable to track today the images show different than reality

    • SrikanthK

      Every time rains are near Chennai we will ensure the site starts choking 🙂

  • SrikanthK

    North suburbs could get good spell

  • SrikanthK

    Once again storms have intensified closer to coast

    • mahamood ali

      Yup it intensified much

      • SrikanthK

        How is the rains in your side

        • mahamood ali

          Just the Drizzle has started Sri , By looking at radar i think Rain Rate will be much Higher

    • narayanan_ky

      It looks good for some 50 mm + there…SRP thundercell is the hope for the central and south chennai probably.

  • gargara

    http://satellite.imd.gov.in/img/Chennai.gif

    This is the latest sounding and I think the latitude/longitude are proper Chennai.

    The dew point mixing ratio is 15 which is quite high. What that means is for 15 gms of water vapor in 1 kg of dry air. Which is quite significant.

    So once you eliminate the inversion normal service can be restored.

    • SrikanthK

      The inversion is far better compared to morning

      • gargara

        That and the dew point curve is touching the pseudo saturated adiabat(red line)

      • gargara

        At the level of LCL both the dew point mixing ratio and the saturation mixing ratio of ambient air are about 15. So that is significant.

  • Yaamesh

    moderate rains for about 15 mins in avadi…

    • SrikanthK

      Super. Finally some rains for the western suburbs

  • Narasimhan Sankaranarayanan

    Any possibilities of TS for pondy?

    • SrikanthK

      Yes there are some storms brewing to your west

      • Narasimhan Sankaranarayanan

        Thank god

  • SrikanthK

    Good set of thunderstorms moving in

    • mahamood ali

      Hope it continues to rain , by back to back storms 🙂

    • narayanan_ky

      Completely cloudy in southern suburbs now.

  • narayanan_ky

    Thundercell south west of tambaram may hit southern suburbs or its fringes soon.

  • SrikanthK

    4 mm in Nungambakkam

  • SrikanthK
  • music starts @ kilpauk..good downpour

    • SrikanthK

      Good enjoy

  • SrikanthK

    Some super intense storms in south Karnataka

    • Malakrishnasamy

      So monsoon revived there? Will that extend for few days?

  • SrikanthK

    Looks like radar is not working again

    • ~Prince~

      only long range radar working !!

      • SrikanthK

        Now SRI is also working

  • SrikanthK

    Parts of Bangalore has got some rains today

  • Super windy here.. Sureshot overhead pop ups @ Kilpauk

  • SrikanthK

    The storms have just bloomed in the sea

    • Areas close to coast might still have got something..

      • SrikanthK

        Some light rains reported

        • Karthik Bhatt

          Drizzled for about 5 mins..

  • Lot of overhead development happening @ Kilpauk

      • gargara

        http://satellite.imd.gov.in/img/Chennai.gif

        So this is about two hours old. Can you say at what time you saw these clouds move in ?

        • An hour or so. Not beyond that… Was gloomy but potential clouds like above was seen only an hour back and it’s still the same

        • mahamood ali

          How the suppressed Chennai is getting rains now , need to know

          • SrikanthK

            Things change constantly if e observe the sounding charts regularly can find the pattern

          • gargara

            It is two hours old. Plus the sounding is not of Chennai. Please check the latitude and longitude first. Sounding is not a forecast. It is a observation. Obviously keeps changing that is why I asked people yesterday to report cloud sightings when a sounding is put up.

            • mahamood ali

              Ok

  • SrikanthK

    Light rains around Yelahanka in Bangalore

    • SrikanthK

      Increasing in intensity as we travel North

      • gargara

        may you keep traveling north

        • SrikanthK

          Yes all the way up to Hyderabad 🙂

  • ~Prince~
  • Vivek

    Any rain forecast for Bangalore ? I haven’t had a sight of sun since morning

    • SrikanthK

      It’s cloudy in Bangalore. On my way to airport possibly north areas getting some light drizzle. Next couple of days Bangalore is well placed I think

  • SrikanthK

    Late night rains are the only possibility fit Chennai in my opinion

  • Ramasamy Prs

    Now saaral mazhai at Erode.

  • barath rakesh

    Pattukotai-13cm

  • gargara

    http://satellite.imd.gov.in/img/Chennai.gif

    Now again DPI marginal. Atmosphere not really unstable at the moment.

    • Shed some light on DPI please… Dew point index? I only see Cape and cin when referring to sounder images

      • gargara

        Dew Point inversion. See the blue line with thick circles. That is the dew point temperature as you goes up the atmosphere. Normally moisture decreases as you go up the atmosphere. When you have a dew point inversion you have moisture increasing as you go up. So that is a dew point inversion.

        In the mid latitudes dew point inversion are usually observed at night but here we are seeing them in the day time as well.

        I posted this old reference the other day – http://journals.ametsoc.org/doi/pdf/10.1175/1520-0450%281968%29007%3C0206%3ADTI%3E2.0.CO%3B2

  • Ramasamy Prs

    Looks like October month sky at Erode.

  • Vivek

    Good afternoon COMK bloggers. I am following COMK for more than an year and decided i should also join as a blogger.

    • barath rakesh

      Welcome

  • https://uploads.disquscdn.com/images/34b10d3b4cf24fa6e587226123d93e650f0a9ca15566f0522b4685f00e28150a.jpg https://uploads.disquscdn.com/images/41d544893e7648f5a4e2ab7b26dcffab5a2b18c8d317b1a3b2d48dce807facc0.jpg

    OPTIMUM SNOWFALL REGION

    – This discusses where the heaviest snow typically falls in association with a mid-latitude cyclone.

    – The two charts that will be discussed to use and what to look for will be the 850-mb analysis chart and the 500-mb analysis chart.

    – First, the 850-mb chart will be discussed.

    – In the 850-mb pressure surface depiction below, the position of the center of the low pressure system and isotherms are shown.

    – The heaviest snow tends to fall just to the northwest of the track that the low pressure is on and where the temperatures ranges from -2 C to -6 C at 850-mb.

    – In this region is the greatest combination of lift and a temperature profile that will support snow.

    – This will tend to produce the heaviest snow is a band-like feature as the low pressure system propagates.

    – It helps to have a moisture source the low pressure can tap into. In the diagram there is moisture advection into the low from the southeast.

    – This moisture wraps up and around the low to supply the fuel for the heavy snow on the northwest side of the low pressure system.

    – Next, the 500-mb chart and where the heaviest snow tends to occur will be discussed.

    – The depiction below is the 500-mb trough.

    – Drawn on the diagram is where the position of the center of the surface low would be.

    – Just like on the 850-mb chart, it is showing the optimum heavy snow region to the northwest of the low.

    – Notice that when looking at the 500-mb trough, the optimum snow is occurring on the right side of the trough axis.

    – This is the same region that will experience upper level divergence from positive vorticity advection and potentially jet streak divergence also.

    – Thus, the region of optimum heavy snow often occurs at the position it does with a mid-latitude cyclone due to the numerous lifting mechanisms that can overlap in this region, a temperature profile that can support snow, and a location where moisture advected into the low pressure system is forced upwards.

    – Strong lifting + abundant moisture + optimum temperature profile = heavy snow.

  • barath rakesh

    Huge numbers of tanjore

  • Prabhu Vishwa

    Isolated thunderstorms on many places of kolar,chittoor, nellore, Vellore and Krishnagiri districts https://uploads.disquscdn.com/images/ba5e4959f46b438c9c5a9c0bc3c93ea2365a7c263b8db7bd038cf19be5bd72ca.png

  • SrikanthK
  • SrikanthK

    Interiors also getting active

    • gargara

      Think when interiors get active Chennai gets suppressed.

      http://satellite.imd.gov.in/img/Chennai.gif

      See the DPI is steep again.

      • mahamood ali

        From Interiors storms only we use to get rain , the condition can change in just a matter of time.

        • gargara

          You tell me. I am only looking at Chennai soundings from this month.

  • SrikanthK
  • ~Prince~

    Towering storm clouds in NW

  • rohit n

    why aren’t the imd radar images getting updated ?

    • SrikanthK

      Not working after 10 AM I think

    • ~Prince~

      now its working !!!

  • gargara

    This sounding looks much better. DPI slope reduced. Some low level lift. And CAPE is high.

    http://satellite.imd.gov.in/img/Chennai.gif

  • Selvakumar(Raijin)

    Great day for Many parts of Tamilnadu…Widespread rains… list is longer

    http://www.imdchennai.gov.in/rf_daily.pdf

  • Akshay

    Wow. -ENSO SSTA signature across Tropical Pacific with Warm Pool in WPAC. https://uploads.disquscdn.com/images/04b38945893b2673456d14f0f36963aef9338ab42b3b6b00fe65ec4cebfabed6.png

  • SrikanthK

    STorms have intensified closer to the coast convergence once again playing a role

    • ~Prince~

      Storm movement west to east ???

  • SrikanthK

    Weak thunderstorms moving towards the coast

  • Selvakumar(Raijin)

    Mini Heat wave in Tokyo area today… Today’s max till Noon is 36.8….Finally Summer kick started here

    • SrikanthK

      Almost summer end time isn’t it

      • Selvakumar(Raijin)

        August is the peak summer month… So it’s the start only

  • gargara

    http://satellite.imd.gov.in/img/CHITTOOR.gif Note how the green bends down just a little bit.

    At last a sounding without DPI and any wonder over night rain ?

    https://trmm.gsfc.nasa.gov/trmm_rain/Events/ATLA/latest_big_half_hourly_gridded.jpg

  • barath rakesh

    Pondy-18mm

  • barath rakesh

    Athirampattinam-12cm,pattukottai-11cm,kallukudi-10cm

  • barath rakesh

    Good morning comk bloggers

  • ~Prince~

    Weak Storms west of Nagiri ????

    • SrikanthK

      Yes those are the remnant storms from last night

  • SrikanthK
    • gargara

      Look at the massive DPI . So do not get carried away by the large CAPE and humidity at lower levels. All of that vapor is directed downwards.

      • SrikanthK

        Interesting Point

      • SrikanthK

        This seems to be the pattern on a regular basis, possibly we need to check some of the interior places on a regular basis if similar pattern exists there

        • gargara

          I checked for Nellore, Chittoor, even Bengaluru rural yesterday.
          They all have it during the day i.e. we have day time dew point inversion. So hand that off to upper level forcing
          Kindly note monsoon and MJO are reviving.

    • Malakrishnasamy

      Anna, not even single rainfall data from erode district available?? Any updates?

      • SrikanthK

        Thalavady has got about 25 mm