North East Monsoon Onset likely

The much awaited rainy season of Tamil Nadu, the North East Monsoon is expected to set in and commence during the next 24 hours aided by favorable conditions. The first spell of rains with the onset is expected as a result out of a churning Low Pressure Area which continues to persist near Sri Lanka and the adjoining SW Bay. Heavy showers/thundershowers are likely along coastal districts of TN along with isolated places in coastal Andhra Pradesh and parts of the Andaman and Nicobar Islands. Meanwhile , in the deep waters of the Arabian Sea, the spinning mass of convective clouds, associated with a well marked Low Pressure Area is likely to intensify into a Depression during next 48 hours. With these Low Pressure systems around, the fishermen are warned to be cautious while venturing out into sea along and off TN coast and Lakshadweep. An Upper Air Cyclonic Circulation is seen to persist near NW Madhya Pradesh, alongside a Western Disturbance to the North. Hail/Thundershowers are likely in parts of East UP.

Chennai will see a day break with clouds all around. Rains to occur in several parts through the day. Maximum temp. will stay around 32 C.

Coimbatore will stay partly cloudy with a mild chance of rains and will see a day time high settling close to 32 C

Madurai to stay cloudy , with rains at pockets of the city and surroundings. Maximum may inch close to 33 C

Trichy to witness cloudy skies , with rains around at times. Temp will stay close to 33 C

Vellore will see cloudy skies as well, with occasional rains as well. Maximum will settle in the low thirties.

Low Pressure systems in the Indian Seas remains on a watch

The Low pressure areas over the Arabian Sea and the Bay of Bengal continues to persist. Meanwhile, conditions continue to be favorable for the onset of North East Monsoon rains over the southern peninsular region around the 28th of October. Under the influence of the Low Pressure system in the Bay, parts of Tamil Nadu and adjoining regions will experience rains. Fishermen are advised not to venture into sea along coastal TN and Lakshadweep owing to rough seas and bad weather in deep sea areas.The extreme north of India will see rains/snow associated with an active Western Disturbance in the region.


Chennai will remain mostly cloudy with rains occasionally at isolated parts of the city. Maximum will stay close to 32 C. Humid conditions will persist.

Coimbatore could remain partly cloudy with a day time high hovering around 32 C

Madurai will see cloudy skies with day time maximum settling in the low to mid thirties. Isolated pockets can see some rainfall activity.

Vellore will stay pleasant with partly cloudy skies with a day time max. inching to 32 C

Trichy to remain partly cloudy with a chance of few isolated showers. Maximum temperature will stay around 33 C

Battle of the Seas

The much awaited weak Tropical system in the Bay of Bengal will be battling another Tropical disturbance in the Arabian sea.The result could well determine the quantum of rains for TN for the end Oct /1st week Nov period. Current forecasts offer a clear advantage to the Arabian Sea System. Another variable in the form of a Western Disturbance (WD) will also determine the track of the weak BOB system. The Brewing system in the Arabian Sea is expected to give bountiful rain to coastal Kerala and substantial rain to southern tip of Tamil Nadu. Increase in rainfall activity will be witnessed in Tamil Nadu from Oct 27th.

As easterly waves are going to set in, Chennai is expected to receive some good showers within the next 3 days and rainfall activity would continue for 3 to 4 days. South Interior Tamil Nadu will have notable rain from Oct 28th. Showers and possibly some steadier, heavier rain moves across entire Tamil Nadu from Oct 28th..
The WD has given the first snowfall in Gulmarg and this will continue to see Rain or Snow at most places over J & K and few places over Uttarakhand. Isolated rainfall is expected in some parts of Maharashtra, East Uttar Pradesh

Chennai – Fair weather likely in day time with late night isolated shower at some places
Vellore – Cold start to Monday as cooler air returns. The Sunny weather will see Max temperature touching 32c
Madurai – Partly cloudy conditions expected in city. Max temperature may touch 31c
Trichy – Partly cloudy conditions expected in city. Mercury may touch 33c at noon. Drizzle expected in late evening.
Coimbatore – Morning clouds will give way to some Sun. Day time Temperature may like to touch 31c. No rain expected

North East Monsoon

Cyclone conceived on 28th Nov 1996 in the Bay of Bengal, crossed near Chennai around 2.30AM IST on 7 Dec 1996.The cyclone persisted for 9 days which is reported to be very long life compared to any cyclone in the Indian Ocean/Bay of Bengal. It caused severe damage to life and property.

Tropical Storm development likely in Bay

A disorganized area of thunderstorm persists to the east of Srilanka.This disturbance is showing some signs of intensification and  would  develop into a low pressure in the next one or two days. Computer models are slowly organizing this weak tropical feature into a cyclonic storm by the end of this week. Currently, conditions are somewhat favorable in south west bay for further development. This system is expected to move closer to TN coast around  October 27 and will bring widespread heavy rainfall to the coastal parts of TN triggering the onset of north east monsoon around that time.



Chennai: Maximum temperature is likely to move closer to 32C with mostly cloudy skies.
Coimbatore: City will see max temperature around 33C. Thunderstorm can be expected during early morning hours
Madurai: City is expected to be  cloudy with a chance of thunderstorm during early morning hours. Temperature will be around 32C.
Vellore: City will remain dry with temperature hovering close to 32C.
Trichy: Temperature to be in 32-33C. Sky will be cloudy with a chance of showers during night/early morning hours.

The NEM Show is round the corner

The Upper Air Cyclonic Circulation (UAC) near Sri Lanka has been triggering moderate showers for North TN yesterday and will continue to seed isolated heavy rains over South TN today. Rest of India will stay dry.
All eyes are on the possible System formation off the Sri Lankan Coast in the North Indian Ocean. Weather Models continue to build this system as the trigger for the North East Monsoon (NEM) Onset over TN. Computer models differ on the track, but there is some consensus on the fact that it will impact South and North TN from Tuesday next week.

Chennai – Maximum temperature would be around 32c and some parts of Chennai are likely to be overcast with drizzles.

Vellore – Temperature may be around 33-34c. Dry weather likely to prevail.

Coimbatore – City likely to have a light rains. Max Temperature to be at 31c.

Trichy – There is no significant rain expected today. Temperature could peak at 34c

Madurai – Day Temperature likely to around with 33-34c with partly cloudy skies.

TN to remain Pleasant & Dry

An Upper Air Circulation (UAC) has formed over SW Bay of Bengal near the Srilankan coast and extends up to 1.5 KM above sea level. Another UAC has formed over the Andaman Sea and extends 3.1 km above sea level. Yesterday’s UAC over Lakshadweep (0.9 KM above sea level) persists.


Rain or thundershowers likely in one or two places over South TN and in some parts of Kerala. Dry weather likely to continue for next 24-48 hours over North Tamil Nadu.
Weather Models are pointing to some action in the Bay towards early/mid next week which could herald NEM into TN. More clarity will be available towards the end of this week.

Chennai – Sky will remain clear, with temperature to be around 33C.

Coimbatore – Partly cloudy sky with light chances of rain. Day temp to be around 32 C.

Madurai – Day temp to remain moderate with temp touching 33C.

Tiruchirappalli – Partly cloudy sky expected with temp around 34-35C.

Vellore – Sky will be partly cloudy with day temp to be around 32C.

No rain threat for Chennai ODI, NEM rains expected to commence 2nd half of next week

Much awaited/delayed NEM is expected to start around 28/29th October. Despite the delay NEM of 1 week, NEM is expected to be normal this year.


Yesterday’s upper air cyclonic circulation over Lakshadweep area now moved away west wards. Another upper air cyclonic circulation lies over Comorin area and neighbourhood and extends upto 0.9 Kilometres above sea level. Dry weather is expected to continue.

Today’s maximum temperature will be between 33-34 and humid. There is no rain threat for today’s cricket match between India and South Africa.

NEM – The Wait Continues

An Upper Air Circulation (UAC) over Lakshadweep persists, causing moderate to heavy rainfall along the coastal regions of Kerala and few parts of South TN. This circulation is expected to move away West and rainfall would reduce gradually in the coming days. Another Western Disturbance is expected to affect Northern states by next week.
There is not going to be any significant activity in the Bay of Bengal as the much expected North East Monsoon (NEM) failed to keep up the normal date of arrival. Unfavorable conditions are likely to surface in the bay for the next 4-5 days. But the wait is not for long. Numerical weather Models continue to show favorable moist Easterly winds making a comeback after Oct 25th followed by a Low Pressure Area (LPA) in the Bay around 27th Oct. To cut the long story short, the much awaited NEM may wash ashore between 26-29th October. Conditions are closely been monitored by weather experts for the onset signs.


Chennai – Fair weather likely with few patches of scattered clouds. Max temp would be close to 33-34c.

Vellore – City will see a comfortable day and night with max settling near 32-33c.

Madurai – Partly cloudy conditions expected with moderate chance of thunderstorms in one or two parts of the city. Max temperature may touch 34c

Trichy – City might see clear skies along with warm conditions. Thermometer may touch 33c. One or two areas might see rainy showers

Coimbatore – Temperature may stick around 30-31c. Thunderstorms expected

South West Monsoon (SWM) bids Adieu

The SWM which started on June 5 has now completely withdrawn from all parts of India. A large subtropical high pressure has formed over Central India, signaling dry weather for most parts of the country in the days to come. A western disturbance persists over North Pakistan and its neighboring region which is expected to move eastwards bringing widespread heavy rainfall for the state of J& K and HP. Another disturbance persists in the Comorin Sea and its adjoining South TN which is likely to bring thunderstorms for South TN, coastal parts of Central TN and Kerala for the next 2 days. North TN will remain mostly dry with a chance of sporadic thundershowers in a few places of coastal region. Normally when SWM withdraws, North east monsoon (NEM) starts in a few days’ time, but this year there will be a delay in the onset of the NEM.
Chennai: Maximum temperature is likely to move closer to 34C. There could be some isolated showers during late night or early morning hours.

Coimbatore: City will see max temperature around 33C with a chance of rain during late night hours.

Madurai: City is expected to be partly cloudy with a chance of thunderstorm during evening/night. Temperature will be around 33C.

Vellore: City will remain dry with temperature hovering close to 33C.

Trichy: Temperature to be in 32-33C. Thunderstorms are expected in the evening hours.

Rains to continue in South TN & Kerala

An Upper Air Cyclonic Circulation (UAC) persists near the Comorin area and adjoining South TN. This would influence the lower level air rotation and the available positive vorticity can generate rain clouds in the region. These rain clouds can generate and extend rains in south TN, adjoining Kerala and some isolated parts of Central Coastal TN as well. Ghat areas bordering TN and Kerala can get some moderate to heavy showers during the same period. In the far north, an eastward moving UAC can generate rain clouds along areas of Jammu & Kashmir and parts of Himachal Pradesh.


Chennai’s day break will be filled with some patches of cumulus clouds with a bit of haze prevailing until the noon hours. Maximum temp. will settle down around 34 C

Coimbatore will stay partly cloudy with a maximum day time temp recording close to 33-34 C

Vellore will have a cloudy day with the max temp hovering around 33 C

Madurai could stay quite warm and humid along with infrequent patches of dark clouds. Maximum will stay close to 33 -34 C. Rain chance persists.

Trichy will stay sunny and max. temp will inch close to 33 C.