Saturday, June 30, 2007

The system 04B has along its way dumped some unusually high amounts of rain,especially in Maharashtra. For the records, some of the rain amounts on 29th. and 30th. in cms were,
on 29th.;
Mahad -50, Mhasala -36, Poladpur -34, Mahabaleshwar -31, Tala -29, Murud, Gaganbawda -25, Margaon - 24, Bhira - 23 Roha-22, Alibag -20, Pali, Harnai -17, Shrivardan -16, Pen -15, Khalapur -13, Matheran -12, Uran, Ratnagiri-11,

Ghats : Dungerwadi-30, Koyna(P), Dwadi, Tamini, Bhira - 20, Shirgaon - 17, Lonavala(O) -14, Lonavala (T) -12,

and on 30th.:
: Mahad -42, Poladpur -35,Murud-33, Mahabaleshwar -32,Mhasala -30, Margaon - 27, Roha-25, Shrivardan, Bhira, Dahanu-21, Tala, Vaibhavwadi-19each, Santacruz, Pali, Harnai, Kankavli, Ratnagiri-17each,Uran, Alibag, Pen-16each, Colaba-15,

Ghats : Koyna(N)-45, Koyna(P)-33, Dungerwadi-26, Tamini-22, Dharavi-25, Shirgaon - 11, Dawdi-16, Ambone-9.

Very heavy rain in two days !

Some city totals for the month of June this year with the variations in brackets:

Mumbai (Colaba): 803 (+265)
Mahableshwar: 1529 (+650)
Goa: 1077 (208)
Pune :233 (+122)

Shows most cities in Maharashtraare way above normal.
In the case of Mumbai, the total has crossed 800 mm after 16 years, last was in 1991, and it is only the 8th. time, it has crossed 800 mm in June in the last 29 years. Noteworthy is the fact that in Mumbai, the monsoon set in on 18th. and most of this 800 mm is in the last 8 days !

Friday, June 29, 2007

Monsoon Watch - 29

The monsoon has set in over Delhi on 28th.June, a day ahead of the normal date.In fact now the monsoon has covered all parts of the country except Rajasthan.This means, the monsoon has reached most of the North India on the normal date,in spite of the delay in the Central parts.In the exterme west,the monsoon has rolled into South Pakistan too, and the Western Himalayas in the extreme North it is ahead of schedule.

After the passing of 03B, 04B is now taking charge.At present,on Friday morning, it is a deep depression, about to gain cyclone strengh (no name),and cross the Orissa coast by Friday noon.Its track north west will pour torrential rains in Central India,and in Maharastra. I feel,by the time it reaches Gujarat, it will have weakened,and just be a normal low,and dry out in the Thar desert (may not give rains in Sindh).The JTWC has issued a tropical cyclone warning for Orissa coast.
The coast of Maharastra,and interior Maharashtra,can get heavy rain Friday through Sunday.
A approaching North India on the 30th.The possible effect of the two systems(W.D. & 04B) could be that large parts of North India, and at the same time, all of Central India,could come under a very wet spell.So, in the interaction of these two systems, all parts of Orissa,.A.P.Chattisgarh,Maharashtra,Gujarat,Goa and the North West of India can experience a wet spell in the next 2/3 days.
Rains will be heavy in Mumbai during the weekend.In the South,the rains may continue to be sparse.
The ECMRWF and a few other model predictions have forecasted, the remnants of 04B could form another low in the bay,around 3rd.July.If true, this would mean a continuous wet spell for central and North India at least till 10th. July.

Monday, June 25, 2007

Tropical Storm 03B after crossing into the Arabian Sea has started intensifying, and is already a "no name "cyclone. It is now off the Sindh coast, about 110 nm. south of Karachi. On intansifying, 03B, will take the last of the 3 options ,mentioned in my last blog. It seems it will cross the Pakistan coast, between 62E and 63E on Tuesday night. Karachi, being on the outskirts, will be spared the heavy rain, and can get moderate rain, but certainly will get very breezy. But the danger from this storm will be floodings, due to heavy rain, in South-West Pakistan and North-East Oman.

On passing into the Arabian Sea, 03B has poured torrential rains in Maharashtra on Saturday and Sunday. Some interesting rain amounts in mms for 24 hrs. on Saturday in Maharashtra/Gujarat:
Bhira – 47o, Koyana(n) – 27o, Koyana (p) -25o, Dungerwadi – 21o,Mhasala - 30o, Colaba - 28o, Vaibhavwadi-25o, Alibaug, Pali, Mahableshwar - 23o each, Poladpur - 22o, Santacruz - 21o, Roha, Tala - 19o each, Matheran, Sawantwadi - 17o each, Panaji-16o, Mangaon, Pen, Mevad, Kolhapur - 15o each, Harnai, Kankavali - 14o each, Devgad – 13o, Khalapur, Ratnagiri - 12o each, Karjat, Veraval - 10o each. And for Sunday :Ambone -180, Tamini -130,Alibag -170, Igatpuri, Mahabaleshwar -150 each.

Having just moved into Gujarat, the monsoon may again delay its northward movement, as the winds in the Arabian Sea are once more pulled into the cyclonic spin.The rains in the east of India too were sparse due to 03B. The west coast (including Mumbai) will experience a sort of lull in the rains for a few days, till a new system activates the winds back to the south west direction.

However, a fresh low has been predicted in the Bay by the 26th. The ECMWF sees this system intensifying into a possible cyclone, to cross Orissa coast, by Friday.

This system will activate the monsoon in the eastern parts of India,and a north-westerly track of the new system will bring the monsoon into Delhi region.

Your views please at ;

Friday, June 22, 2007

I would rather call this piece the "03B" watch.

As estimated, the deep depression, or a weak cyclone ,crossed the east coast of India, by Friday afternoon. By then it had poured 320 mms of rain, in 24 hrs. over a few places in A.P. and on Friday, during the day, only in 9 poured out a massive 245 mm of rain in Kurnool (A.P.).

The forecast was, rightly, that this 03B would bring excessive rains along the heartland of India,with some flooding in A.P. and along its path. the west coast too is to get excessive rain, upto 300 mms from saturday.

But, according to me, the latest images do not show as much of a strenght maintained by 03B, or so it seems to me. It seems to have weakened faster inland.

Now, the future course. Models predict that the system will re enter the Arabian Sea. Ok, so far. One view says of the system getting stronger and heading along the sea to, yes, Oman again !By the 25th.
Another view suggests the system on entering the Arabian Sea goes north along the west coast of India and after hitting the gujarat coast, going into Rajasthan, again by the 25th.

And yet, another model of forecast does suggest of the re entering of the system in the Arabian Sea, and going for the Sindh coast in Pakistan. Ok, fairly close to the second, forecast.This too could be around the 26th.

Well, model predictions have shown that they can be a little off the course, and nature has always proved it can take its own course.

Anyway, one of the estimates will surely prove correct.

Tuesday, June 19, 2007

Monsoon Watch - 28

Monsoon has moved into Mumbai today, 18th. June, as per the statement by the IMD.

The monsoon,though set in, is still a weak current over Mumbai, and rainfall still sparse along the west coast north of Goa. Even below Goa, it is not the usual monsoon downpour.

An estimate is made by the ECMWF of a low being formed in the bay by the 20th. A bold forecast is made of the progress of this low. It is estimated that this low will travel from the coast off A.P. through India right upto Gujarat, by Friday/saturday, and along its path, heavy rain is expected. If this forecast holds good,( I do not trust the behaviour of the monsoon this year), it will be extremely beneficial to the parched areas of the northern region of the Indian peninsula.

Another confusing GSM numerical forecast is a hint of a low pressure (tropical depression or even cyclone) showing up over the eastern Arabian Sea late in the week.

It is a bit difficult to exactly understand the actual happening, only can guess that the weather is set to become increasingly unsettled.

Positive signs : Good south westerly flow in the Arabian Sea, trough of low pressure along the west coast.
Negative signs : low day temperatures in the northern region of the sub continent. Day temperatures as low as 10 c below the normal, heavy rain all along the north, and heat low area shrinking in the desert region of India/Pakistan.

Saturday, June 16, 2007

Monsoon Watch - 27

The monsoon current is seen progressing very slowly in the Arabian Sea branch,but the bay branch shows fast westwards movement along the northern and eastern areas of India, with it having almost reached Lucknow by the 15th.June. Delhi recieved heavy pre monsoon rain on 15th/16, along with the entire northern areas of the subcontnent and some heavy rain in north Pakistan too. The result is a good fall in the day temperatures. The map shows the variation from the normal,and is clear that the entire northern belt is pleasantly below ythe normal. (Sharp contrast from two days ago).
This has occured , contrary to my forecast of the heat returning, as the rain bearing "easterly wave'' remained sort of intact, resulting in pre monsoon showers all along the U.P.and Bihar regions.

This COLA forecast indicates moderately heavy rains along the west upto Mumbai, but very little inland till 23rd. June. From 23rd to 1st. july the forecast indictes heavy rain along the west coast and rain spreading to the north India too. Should happen, as ECMWF and the IMD have predictede a low to form in the bay around the 20th. June.( please refer previous MW too).

But the past 12 hrs rain accumalation , as on today shows very little rain inland in the peninsula India,except a patch in the east, as seen in this image.

So, the estimate of much rain along the west coast from the week of 10th. of June by computer models has again been betrayed, due to cooling of the northern belt, by the prevailing easterly wave there, and thus preventing the jet stream easterlies of the southern peninsula from moving north. The jet streams have been stuck at 10N location,near Chennai,but are expected to move north by 16th.

Yes, as per the conditions now, the positive side is the south west winds formation intact, the jet stream moving up, and" fairly" good clouding along the west coast, and the negative sides are average sea temperatures, low day temperatures in the India/Pakistan northern areas( highest in the area was 45 c, compared to 52 c , 3 days ago), no low formed yet in either sea, very little wind strenght in Mumbai and coastal regions today. IMD has predicted monsoon to advance further up the west coast today. But , it could be today, tomorrow or three days, I should not venture out with a forecast at this stage of this year's monsoon.(Unpredictable and irregular performance as yet by any standards).

Wednesday, June 13, 2007

Monsoon Watch - 26

The heat wave in the northern sub continent last few days has set up a perfect heat gradiant for the monsoon to advance northwards. The heat low gradiant helps the alignment of a suitable pressure difference from the south, where Thiruvananthpuram is at 1010 mb. and to the northwest where Rajasthan/Pakistan desert areas are at 992 mb. now.

This low pressure area spans now from Arabia to northwest India, and the surface winds from the Arabian sea to the Indian peninsula are as they should be now. The IMD has confirmed the monsoon's further advance into south Konkan.

Thelinks of the monsoon requirment are in place now, and the monsoon confirms this by its advance into the coastal Maharashtra region today. Though monsoon rains are not in full strenght yet, the south west winds are never the less pushing ahead, and rain intensity should increase along west coast initially, and later inlands. For this, the Arabian Sea or the bay has to form a low, or warm up a bit more as mentioned in MW-25.

Mumbai has been uncomfortable with a temperature range of 35c as high and 30 c as low with high humidity levels. But the city should get the monsoon by Friday, as there is now no hindrance to stop the movement. But the initial strenght( amount of rain) and inland thrust of the monsoon will depend on the early formation of a low in the bay.

As mentioned , northern areas of the sub continent may see a revival of the heat wave in a couple of days.


Tuesday, June 12, 2007

Monsoon Watch - 25

The monsoon continues with its progress in the eastern parts of India and is advancing well due to an "easterly wave " from the far east (the one causing excessive rain in eastern China).The low pressure area off the coast of Orssa seems to be evolving,with some heavy rain expected over Orissa region.
In fact , this wave has resulted in easterly winds in the northern plains, causing some rain and a relief from the extensive heat. But the hot northwesterlies will resume once this wave dies out, in a couple of days.

The latest positive sign I can visulise for the monsoon to move north along the west coast of India is the development of the well formed seasonal heat low over northwest India and extending into Pakiastan.With this ready, the monsoon currents need not wait for a low in the Arabian Sea to move north.As mentioned in my previous "MW's", this heat low is a very crucial component for the monsoon advancing, and I have always stressed upon this development.The ideal pressure gradiant to help the northward thrust of the monsoon is also there, and conditions are ready for the monsoon clouds to penetrate further north substantially in 2/3 days.

It is only hoped, that predictions and forecast estimates do not change this time, as much of the sub continent plains and the west coast need the rains, stalled near Goa, since14 days now. During this period after the initial monsoon burst, forecasts and calculations have gone haywire twice, once with Gonu taking the monsoon away from the Indian coast, and again with the south westerly winds suddenly getting strong, and then getting weak equally fast, as the expected low in the Bay did not form in the second week of June. Another point worth noting, is that proir to Gonu, I have always mentioned that the sea temperature is perfect at 31-32 c for the quick formation of monsoon clouds. But post Gonu, it is observed that the Arabian sea temperature dropped to 28 c (but slowly heatinf again), and this does not hasten formation of substantial clouding.

We can only calculate, forecast or observe the weather, not control it.

For your views:

Monday, June 11, 2007

Monsoon Watch - 24

The progress of the Arabian Sea branch of the monsoon is held up due to the lack of sufficient wind "push" from the rear. This is evident from this streamline (IMD). It indicates a weaker wind north of Goa coast, and lack of any formation of a low.Clearly now a couple of days more delay of the northward approach of the monsoon along the west coast ?Earliar the forecast arrival for Mumbai was 8th.June.

The bay arm is active ,and made up for the delay in onset time. Its progress, now towards Bihar is maintained, and the winds above the trough have turned east.

Even the ECMWF, European model, has been indicating the formation of a low in the bay since the past few days. When formed, this could surely hasten up the flow of the monsoon along the west coast of India.
Models show the anticipated low to form around the head of the bay( already behind forecast schedule).This low ,when formed, must be followed by weather observers, as it would interact with the monsoon flow (that is winds from the Arabian sea would get stronger), and scale up the rain along the west coast and into Gujarat and interior Maharashtra,and central peninsula .

ECMWF also sees another low along the south east coast of India. This, if it forms, should also be obsereved, as its inland movement could mean good rain for the peninsula.When these low's form and what happens is to be seen and followed as no amount of forecasting seems to hold true.(One reader asks ,"is the monsoon behaviour crazy this year ?). I say ,No, only we are not able to understand the weather and monsoon systems !

Meanwhile there is no respite from the heat wave in the northern parts of the sub continent. Its getting hotter and even hotter. This temperature map shows the various 50' s and a single 52 across Pakistan. Most of the norhtern plains of India reel under temperatures between 45 - 48 c. The north Indian hill station, Simla had a high of 31.2 c, reching 31 after 12 years, and Srinagar in Kashmir was at 34.5 c (+6 c).

Contact for your views:

Sunday, June 10, 2007

Todays Readings of the extreme heat wave in the sub continent are worth noting:

Sibi,Larkana and Mianwali (all Pakistan): 51c
Bannu and Sargodha (Pakistan) : 50c
Ganganagar(I),Jacobabad and Nawabshah(P): 49
Faisalbad,DIKhan ,Bhawalnagar(All P) :48c

With several many towns in India and Pakistan between 45-47c.

To my knoweledge, the temperatures above 48 c were the hottest spots on the earth today.

Exceptional night temperature again was Gwalior with 36.3 c

Saturday, June 09, 2007

Monsoon Watch - 23

With Gonu having crossed the Oman coast, its pull has diminished over the Arabian Sea. The monsoon south westerlies have once again picked up in strenght.Normally it would have taken a bit longer for the winds to re-group, considering the massive intensity of Gonu.But the kinetic energy has been recouped, and the monsoon flow is once again dominating the Arabian Sea.(See last blog).

The forecast model NCMWRF cites an increase in sea level pressure gradiant along the west coast of India.This means strenghening of the monsoon flow over Arabian Sea, peninsula India, and the Bay branch of the monsoon current from Saturday. So now the monsoon can advance up into coastal Maharashtra and the northeastern states (already announced by IMD), from Saturday onwards. Taking a look at the satellite image of the sea, and the force it is generating, I think the monsoon will be in an active phase along the west coast from early next week. Mumbai may see heavy rains commencing Sunday/Monday onwards.

This is matched by an intesifying of the heat wave all over the northern sub continent. The highest temperature today was at Larkana in Pakistan at 50 c, and 48.8 c at Nawabshah, 48 c at Sibbi. (Last year the first 50 was on 26th. May at Jacobabad). Today, in India 46.6 c was recorded at Ganganagar, 45.8 at Amrisar,and several places at 45 c. Gwalior had an unbelievable minimum temperature of 36 c !Delhi was low at 33.5 c !

Wednesday, June 06, 2007

The center of Cyclone Gonu has moved away from the coast east and northeast of Muscat. Meanwhile, at the Seeb International Airport, near Muscat, the latest weather observations show very heavy rains 6th.June almost throughout the day, with storms and low visibility, strong winds and thunder. As Jim(Accuweather) says correctly," the waterfront is much stormier, maybe with winds causing structural damage and felling trees." Estimated highest winds are at 75 knots, or 140 kph--a Category-1 hurricane on the Saffir-Simpson scale.

Now, Gonu should weaken with the inflow of dry desert air, and within the next 24hrs., show up as a normal rain area east of the Straits of Hormuz.

Danger to life and property is surely possible, from excessive rainfall and flash flooding wherever the storm winds and rains are driven against the highlands off the coast of Oman

The Arabian Sea has become bereft of any significant cloud formation, as of today. But,as is possible, regrouping of the monsoon current can start in 2 days, and the west coast of India should see increase in rainfall subsequently.Till then, for the next few days, the occasional thunderstorm will pop up and dot the interior s of Maharashtra,Karnatak and the southern peninsula India. The west coast areas will too have the odd thunder activity.

For your views:

Tuesday, June 05, 2007

This satellite image of Gonu from DSRS( 1800 hrs.UTC of 4th.) says it all !

Gonu has intensified into a "super cyclone",with an estimated core pressure of only 920 mb,and core winds of 160 kts/hr. This is phenomenal, and landfall at this intensity (if maintained) could be damaging. One cannot rule out unusually wet and windy weather for Oman, Dubai and parts of Saudi Arabia in the next 2 days.

Gonu is now moving north-west and as expected can strike the Oman coast (mostly the north-east coast) by the evening of 5th. But its further intensificaton is in doubt, as the waters it now enters will be not as warm as the current path. Even, on crossing the land, the cyclone should weaken rapidly,as it will be encountering dry air of the Arabian Peninsula.

Monsoon Watch - 22

Gonu has sapped up all the energy available from the Arabian Sea, and redirected the winds towards its centre.
The satellite image also shows a band of monsoon clouds forming south of the cyclone, and not attached to , around the centre of the Arabian Sea, between India and the African coast. Maintaining the stand that regrouping of the monsoon clouds can start after the cyclone crosses land, we can presume the regular monsoon to regenerate force by the 7th.As required (see prevoius blog), a ridge is established over the northern sub continent. Northward movement along the west coast of India can resume from the 8th. and the schedule for Mumbai could be kept for the 8th. or 9th. A fresh monsoon surge may not take more than a day or two more to progress into Gujarat and interior Maharashtra.

A friend has asked about the heat in Delhi. Well, presuming the north gets hot now onwards, the monsoon should be on time in Delhi, by the end of this month !

Sunday, June 03, 2007

The Arabian Sea today hosts a"severe Cyclonic Storm"-Gonu.

The result is that this severe system is attracting more and more of the moist westerly flows, meant for the regular monsoon, and is further intensifying itself, as mentioned in the last blog. It is now moving west-north-west. Most likely "Gonu" will strike the south Oman coast by Monday evening. As was expected, the monsoon flow will get temporarily halted as a result. Forecast models show that the monsoon winds should take a couple of days to re-group after the cyclone crosses the coast and halts pulling the winds towards its core. Hence the northward march of the monsoon may start after 6th. June, and enter Mumbai only around 8th.June. Further movement into Gujarat and interior Maharashtra can be around 10/11 June.

Bay Region
Now,the seasonal trough which had formed around central India on May 7th, has been pushed to the foothills of the Himalayas.The seasonal trough can then get converted ,with the arrival of regular mosoon flow, into an east-west trough and get activated .This can create a trough, or even a "low" at the head of the Bay, and trigger in the required monsoon activity in the eastern region. This means the monsoon may enter the North East also around the 8th.June.

Meanwhile the heat has started intensifying with 47c in Pakistan and a few 45c in India.

Friday, June 01, 2007

Monsoon Watch - 21

Is the situation favourable for the further advance of the monsoon into Goa and Maharashtra, or is it not ? This is the very complicated question that every forecast model is facing, and as Jim from Accuweather aptly puts it -" Given that rainfall is often poorly handled by numerical forecast models," unquote, it is one of the most complex situation in recent times.

The monsoon has advanced upto Karnatak coast in the west, and upto the Andaman Islands in the Bay. Now in the west, today ,a depression has formed, which has all the possibilities of strenghtning and going upto the cyclone stage. Good enough to pull the monsoon up the west coast. But due to a ridge axis on the sub continent, the system is forecasted to move North west, away from the west coast and towards Southern Oman. That means, energy will be absorbed towards the system, and the winds will twirl around the cyclone, leaving little for the monsoon to advance up the west coast.In this eventuallity,further movement of the monsoon can be delayed,by 4/5 days, till the clouds regroup again. As a result, even the IMD has delayed the further advanve of the monsoon by at least another 3 days.

But the above mentioned ridge, or high aloft is necassary to attract the monsoon upwards after the passing of the Arabian Sea system.This ridge is exactly the opposite of a W.D. In fact, due to this, the temperatures in the North have started heating, with 4 places at 46c in Pakistan today and 2 places with 45c in India today. So it is better the system moves away from the west coast.

As ,if this Arabian Sea system, does not move North West, then its moving north will surely bring rain to the west coast, but will only mean that the much required mentioned above ridge is not effective. And further it will only be a passing phase of rain, as then a W.D. will prevail, and absorb the system, and bring delays in the monsoon by upto a week.

The Bay segment seems to be still dormant. No further advance is seen in the next few days, and development of a system in the Bay has to wait till a "pulse" imerges from the far east, or from the Bay itself.After the cyclone "Akash", the Bay waters did cool down a lot, and heating again is required to start some activity.

But ,overall, the assessment has been quite on target. Since the MW-1 on 1st. April, through April, it has been maintained that the monsoon should hit Kerala in the "last week of May''
or "ahead of schedule". Throughout May, the sea tempertaures and heat waves and pressures were observed, and the targets for the monsoon date was being mentioned in the MW's, and Mumbai's pre monsoon shower was indicated way ahead on 8th. May. As I always write, we have to only observe,we cannot control. One can observe and put in views, but one can never actually control the actual weather event.

In the next few MW's I shall also try to analyse the quantum of rain expected during the rainy season. Please give your views and comments on this at