Chennai has more than good chance for rains tonight and tomorrow

24th Forecast

Lets first see the postive factors
1. Dipping of Jetstreams – When a jet stream dips, it creates upper divergence and there by increasing convergence at lower levels. These rains are always intense and are associated with hails.
2. The upper trough is caught between two HPA and a valley like trough is created. The sharper the trough the more the intense the rains are.
3. CAPE – 4000 (J/kg) is available near Chennai. So we just need a TS over Chennai. The abundant energy will magnify the TS.
4. Moisture Content – No need to worry about this. You may already felt the sultry feeling. Moisture is available right from upper level to surface levels.

Negative factors.
1. All the above are assumed factors
2. The storms should not peak too early before coming to our Bermuda triangle
3. Chennai is located southern coastal part of India. This region not known to get rains in April.

I personally feel that we have more than good chance for rains in Chennai in next two days as the postive factors cannot be ignored.

1,505 thoughts on “Chennai has more than good chance for rains tonight and tomorrow

  1. Possibilities of rain well explained in the heading. Lets pray for the record breaking rainy day in April for Chennai.

  2. According to GFS – The TS is going to stay near Chennai for a While. Exicting day ahead.

    • As mentioned yesterday we will have only one view – i.e. just receive rain from tonight – rest does not matter

  3. Hal ap 49mm as per newspaper reports. Blore City 53mm. Would be interesting to see BBMP daily report today. Looks like storm passed almost exact east to west. Even west central blore has got good numbers. Areas on fringe of storm like mine got hail lot of wind and lightning show but significantly lesser rain.

    • Areas like hoodi garudachapalya which got heavy rains last week hardly got anything yesterday. Around 5mm. Rammurthy nagar horamavu just 0.5mm or even 0. Kasturi nagar was comparatively luckier. ๐Ÿ™‚

  4. This posting by RAkesh Rajan in FB -Heavy T showers forecast for Chennai, and many zones along SE India on friday evening, midnight.

  5. More “damaging” nor’westers ahead today for Bihar, Odisha and Bengal. Take care. #iwm

    • City has a lead of ~3cm over sahakarnagar nw…. and HAL AP is ahead of us too! Hebbal-Sahakarnagar belt has been pretty unlucky this month…. Our time will come soon ๐Ÿ™‚

      • My area is like a consistent performer.. Never topping but always getting some rains.. ๐Ÿ™‚

      • Radakrishna ward has got 13.5mm whereas my place could be arnd 7-8mm.rains gradually increased south of my place..

  6. OMG….models accurately predicted heavy rains for CAP-NAP on 24th. Today early morning CAP districts Krishna & Guntur and Khammam, Warangal (TS) got 20-30 mm thunderous rains.

    The above rain belt moving towards NAP and later it will weaken.

    NTN rainfall (Chennai) on 24th is in due. I expect these rains will come form N/NE/E (by inverted trough as partha mentioned??) by today evening/tomorrow early morning.

  7. Vela,

    Your point “more hail storms and poor SWM” is a valid point.

    More the hailstroms in pre-monsoon period is the indication of strong sub-tropical jet stream pattern (related moisture coming from mid-latitude westerly winds). Elnino (Lanina) will enhance (weaken) the strength of sub-tropical jet-streams.

    So when sub-tropical jet-stream patterns has more strength then Somali jet-stream (SWM-related) has to struggle get into action. If Somali-jet stream pattern is in weak position then it will result in poor SWM (in-terms of distribution of rainfall).

  8. By seeing positive factors by PJ…
    these positive factors are all synoptic factors for rain

    and all negative factors are common factors

  9. Alert….
    Elnino-2015 (forecast) will take the “Spring bite” just similar to Elnino-2014 failed forecasts??? Earliest indications look like that.

    • No need to worry about NEM-2015, which will be having better rainfall prospects than NEM-2014 even if Elnino in 2015 doesn’t establish according to the earlier forecast.

  10. Erode/Salem: Heavy rain accompanied by hailstorm lashed Salem bringing down the temperature while trees were uprooted in Erode district, officials said today.

    The hailstorm lashed Salem around five pm yesterday, much to the relief of people sweltering under the heat.

    In Erode, heavy rain accompanied by gale uprooted number of trees in Bharathy Nagar, Kollampalayam, Perundurai road and some other places, last night.

    A big Banyan tree was uprooted in Perundurai causing traffic disruption for more than three hours from 8 p.M, officials said.

  11. Heavy rain in kakinada…Tuni…
    hailstorms in araku and paderu
    Lammasingi recording 8 degree temperature with dense fog and heavy rain

      • kashmir of AP. Another name for this Lambasingi village is Korra Bayalu. Korra means ยดstickยด, Bayalu
        means โ€˜outsideโ€™, in the local language this means โ€œif some one stays
        outside the house in the open they will freeze like a stickโ€

  12. New thunderstorms extending towards the southern areas of west central bay of bengal…soon ongole prakasam nellore chennai may get favourable conditions.
    Though at present surface winds at 1000hpa are not favourable the winds at 700 hpa may dip down.
    large amount of energy available at nellore chennai belt…
    moisture content also favourable….
    needs close monitoring

  13. very late night Friday rains or very early mor rains too start..Chennai to rock in next 12 hrs, but some evening showers cannot be ruled out today..

  14. Palani (Dindigul Dist)


    Perundurai (Erode Dist), Salem (Salem Dist)

    6 each

    Dharmapuri pto (Dharmapuri Dist)


    Hogenekal (Dharmapuri Dist), Coimbatore south (Coimbatore Dist), Virinjipuram AWS (Vellore Dist)


      • The last hailstorm in n.blore (or sahakarnagar to be specific) happened 8-10 years back i think…. i vaguely remember it was a very heavy 15-20 min rain and the lawn in my house was painted white with hailstones ๐Ÿ™‚

      • On may 24th or 25th 2011 there was hail storm in my place.I remember it well.. I even collected it in my hands.but very small hails only though and also in April 2010 there was hail storm :)..In May 2013 many parts of Blore reported hail storms for twice..even imd reported once.. but there wasn’t in our areas.

      • Oh don’t remember these ๐Ÿ˜ฆ It may have been May 24th 2011 as from my RG archives i have written down that 37mm was recorded on that day…. And it was a working day, so high chances that I might have missed it….

  15. for one second KEA widget showed 37* and now in down ward trend, i think this is the highest temp. so far this month.

  16. Veppa salanama Shankaran. Why dont u ask Ramanan sir. Why there was no rain yesterday. Veppam was there la.

    Without dipping of trough, we wont get rains.

  17. i think IMD chennai is lazy enough to explain the scientific reason for rains they simply term it as veppasalanam

  18. @bhaskaran19:disqus Why don’t you believe what you see? Yesterday Kea recorded 35.8, IMD AWS recorded 35.3 only. But official IMD reading was 35.8 only.
    Today Kea recorded 37.0, where as IMD AWS recorded max of 35.3 only. This is still way above the 34 you are mentioning. I think official IMD reading will be around 36.5. Lets wait and see.

  19. See the Humdidity in pondy during evenning, it is 80%. It is going to be sultery this aft/ eve. Any comments on this

  20. Yes vela sir
    100% people interested only to enjoy rains
    50% people interested to observe how it rains
    20% people interested to investigate when and where it rains( but only in rainy season)
    10% people do it in all seasons
    Only 2% of the people like us always interested on climate and changes in weather in all seasons irrespective of places

  21. Doppler radar in Karaikal by May-end

    The Doppler Weather Radar Station located at Karaikal will be commissioned by May-end.

    It will be a state-of-the-art facility featuring the most sophisticated technology in Tamil Nadu and Puduchery region, said P.S.Biju, station director.

    It will be an-all weather radar and can register data on rainfall, cyclone detection, velocity of wind and it will track cyclone movement. It will gauge upper air wind, an important data input for flights operating from the Tiruchi airport and the airport to be set up at Karaikal

  22. I always believed imd had all the equipment to do forecasting … infact they have everything in their daily weather reports ….but for some reason they never take it to common man may be media is not supportive to do a weather report like cnn or bbc or al jazeera… fact is also 80 prrcent of the v population don’t want it. ..ramanan sir my request would be improvise the weather reprint take it to next level to the common man

    • It is time we take masses to next level on weather by the way how many noticed in sun tv news when they report on weather during rainy days they show old satellite picture completely irrelevant to current weather systems

  23. from the day i follow cyclone and rain updates through radio, when t.v was not popular, the functioning of Imd remains same, only late updates, those days technology boom is not their, but today?

    • No that’s because they don’t coordinate with media or vice versa … They have all the forecasts with them

    • imd has com a looong way since then! jst an example wat we all crave for every ten min update?? RADAR …no doubt imd is more sophisticated now but the prob lies with the country n infra….most ppl hav better things to do n survive every day than concern abt weather…

      • n media is not at all intrested to cover their seminars workshops etc, its oly durin the cyclone time they scurry to report tat too for competing with other media agencies who gets first.. pathetic ppl

  24. Watch out for an UAC forming by tomorrow evening near North Coastal Tamil Nadu, During easterlies when UAC forms over East of North Tamil Nadu Coast then it will hamper our chances, but this the winds are going to come from North and NNE on Saturday, so more rain expected on Saturday night.

  25. Partha,
    AP & Telangana states going to receive normal/above normal SWM-rains as against JAMSTEC-forecast (even IMD’s monthly rainfall forecasts indicate this good rainfall scenario for AP&TS).

  26. The following 3 factors are not in favor for Elnino-evolution in 2015 (though its early). One has keep an eye on the following 3 factors before end of spring (till may 31st) or at least end of June to see how forecasted elnino-2015 unfolds.

    (1) the SST-anomalies started warming again at A-box after slight cooling trend.

    (2) SOI oscillating around -4. It must show decreasing trend and stay at least below -5 before spring.

    (3) MJO avoiding date-line presence, which is not a good indication for keeping continuous WWB


  27. Till now Krishna, Guntur, Prakasam, anathapur, Warangal, Khammam districts recorded heavy rainfalls today morning.

  28. a low lvl circulation near comrin area is causing som ts developments for south and coastal tn near kkl n surroundings,

    looks a busy day for south too models again failed to pick..

  29. Still there is plenty of moisture distribution in the interior districts to cause thunder storm like yesterday….. Should see today’s evening developments

  30. From todays Blore IMD report:

    A squall has been reported at 18:07 hrs IST speed gusting 106 kmph from Easterly
    direction in Bangalore HAL Airport on 23.04.2015.


  31. also winds in vskp n machili radar is strong nw for us its starting to change now in upper lvls.. taking perfect 700 route

  32. PJ
    Great and a simple explanation on Jet Stream troughs above.Very well articulated and explained.Take a bow!
    But let us go slow on IMD comments…Let us progress with all.

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