Monsoon To Enter Kerala By May 30, Mumbai By June 8

MAY 23, 2017, TUESDAY 

Looking at forecast charts by global Numerical Weather Prediction models one can safely say that the southwest monsoon is set to arrive in Kerala by May 30, 2017. Our estimate is it will hit Goa by June 4 and Mumbai by June 7-8.

The monsoon onset we are talking about as decided by parameters set by the indian Meteorological Department. If we were to go by amount of rainfall alone, heavy thunderstorms will start lashing Kerala in the next 3-4 days.

According to accumulated rainfall forecast charts by the European agency, ECMWF, by June 1, parts of Kerala will have received a whopping 334 millimetres of rain. Monsoon is expected to cover coastal Karnataka by June 1 itself.

After the Kerala onset, the rains will clamber up the latitudes quickly and reach Mumbai by June 8. Fortunately for Indian monsoon this year there have been no depressions/tropical cyclones in either the Arabian Sea or Bay of Bengal which suck away its energy and throw it in another direction, thus slowing down its progress.

There is little possibility of a storm in the seas except for a Bay of Bengal upper air cyclonic circulation which may intensify to a low pressure area/tropical storm by month end. But even that is expected to move into Bangladesh/Indian northeast, thus it will actually hasten monsoon's entry into eastern India.

According to the ECMWF forecast rains will be knocking on Goa's doorsteps by June 2.

Monsoon arrival means massive changes in upper atmosphere winds, some 12-13 kilometres high in the air. This June 1 forecast map shows the monsoon winds are already blowing over peninsular India. The perennial easterly jet stream has been pushed northwards into Tibet. This occurs every year during monsoon time.

There is sobering news for those expecting a bumper harvest this year. In it's latest forecast the Bureau of Meteorology says the Indian Ocean Dipole may not be so positive in August. In fact the European model predicts a weak IOD this year.

Similarly NASA and the ECMWF says El Niño may rear it's ugly head by August. Only NOAA paints a rosier picture. Be prepared for poor rains in August-September unless of course the picture changes by then.

Positive Indian Ocean Dipole To Intensify Monsoon 2017

APRIL 22, 2017, SATURDAY

There is good news for India this year. The European forecast model ECMWF has predicted that the patron saint of South Asian monsoon, the Indian Ocean Dipole (IOD) is going to start turning positive from June 2017. And it is going to become even more stronger by September. We all know that a positive IOD means good monsoon rains in India, especially the Arabian Sea wing of the monsoon.

What is the Indian Ocean Dipole? This is a coupled phenomenon where the eastern and western parts of the Indian Ocean get alternately hotter or colder than the other part. When the western part gets warmer than the eastern part, it is called positive IOD. The coast near Africa Somalia gets warmer, throws out more thunderstorms and rain clouds into the Arabian Sea ultimately.

The Arabian Sea was impotent in 2016 because it was a negative or neutral IOD year. That is why there were no tropical cyclones in the sea last year. The Arabian Sea wing of the monsoon in 2016 was almost non-existent.

Not this year.

This year as IOD turns positive by June 2017, the Arabian Sea is going to turn into a vigorous stud, hurling thunderstorms, depressions, cyclones and what not.

The CFS model has confirmed that the sea is going to turn over-active in June. Watch out , Gujarat, Sindh, Oman. The Arabian Sea is going to marry IOD in June and going bear many storms.

Lastly we have to mention that there is going to be a worm in the monsoon 2017 soup. El Niño is going to turn positive by August. The fate of the monsoon this year will be decided by the tug-of-war between IOD and El Niño. Who will win? If IOD wins, we will have a good monsoon. If El Niño wins we will have a poor August-September monsoon.

Indian Monsoon 2017 Forecast: Mixed Signals

MARCH 29, 2017

The bad news for India where the summer monsoon 2017 is concerned is that the hated villain, El Niño, is going to come back by August this year. We all know when El Niño comes visiting the rains dry up considerably.

That is why private weather forecaster Skymet has portended deficient rainfall for India this year. It says 95% of normal ( +\- 5%).

But there is some good news too. The knight  in shining armour, IOD, Indian Ocean Dipole is going to turn positive by August 2017. That means lots and lots of rains in South Asia.

On the whole, we think monsoon 2017 is going to be good for India and South Asia. The CFS (Climate Forecast System) too is pretty bullish, predicting good rains in August-September-October. There is a chance of a storm/ depression in the Bay of Bengal in May and in the Arabian Sea in June going by its predictions.

Good rains are expected on the Indian west coast in June according to ECMWF forecasts.

Most forecasters paint a nightmare scenario for Indian monsoon when El Niño is imminent. They are pessimistic about the Indian Ocean dipole being able to negate it's ill effects. But an article in the journal of American Meteorological Society points out that "it was found that the IOD also acts to weaken the El Niño–induced drought over India".

And the IOD is going to be strongly positive this year, hence we are hopeful of  good rains this year.

THE POSSIBILITY OF EL NINO IN AUGUST IS ONLY 50%. WE FEEL THE THREAT HAS BEEN OVER-RATED

FORECAST MODELS SUGGEST EL NINO WILL COME BY AUGUST 

IOD, INDIAN OCEAN DIPOLE WILL TURN STRONGLY POSITIVE BY AUGUST 

Meanwhile thunderstorm activity has started in Indian North Eastern states early this year. A good sign.  And this will continue right till the arrival of monsoons, especially in the states of Manipur, Nagaland and Mizoram.

The NMME (North American Multimodel Ensemble) model expects a depression/cyclone to bring good rains in Gujarat/Sindh in June. This model predicts a dismal rainfall picture for monsoon 2017, but it is to be taken with a pinch of salt. Almost all its forecasts for 2016 went off target.

The CFS model hints at thunderstorm activity starting in Kerala from May 10-15, 2017. Mumbai will receive its first showers by June 8, Saurashtra-Gujarat by June 12.

No Cyclone For Now In Arabian Sea

There is disappointing news for cyclone enthusiasts. Latest forecasts indicate that the possibility of a storm developing in the Arabian Sea is receding.

We had earlier portended that cyclone Chapala was imminent in the Arabian Sea on September 20, 2015. Latest data from the GFS model rules out this possibility.

The European Model denies even a low pressure in the Arabian Sea.

But a low pressure in the Bay of Bengal is very much in the cards. This low will be born within a couple of days. The ECMWF model is bearish on this system. It might throw down a lot of rain in Andhra and Telangana but then it expects it to fizzle out.

The GFS model is much more bullish. We stand by our earlier forecast of the Bay of Bengal low moving across Andhra, Telangana, Maharashtra and then rejuvenating in the Arabian Sea on September 20, 2015.

So lots of rain on Konkan coast and Mumbai around then. The low in the Arabian Sea will then move to coastal Saurashtra around September 22, but the chances of this low developing into a cyclone seems remote for now.

But what we say now may change in the coming days, so taking today's forecast as gospel truth would be a mistake. We are just reporting the trends. Anything can happen on September 20, 2015.

We notice another low developing in the Arabian Sea around September 25. A cyclone perhaps? But more on that as the situation develops.

Now some good news and some bad news.

The bad news is bad boy El Nino is still very strong even in September. It screwed up the Indian monsoon rains in 2015.

The good news is Indian Ocean Dipole (IOD) is strongly positive presently. A positive IOD means good rains and storms in North Indian Ocean.

Bad news. El Nino is still strong in September

Good news! Indian Ocean Dipole very positive presently

EQUINOO Will Bring A Good 2015 Monsoon For India?

NOAA has said that there is a 90% chance of El Nino staying late summer, 80% chance that this unwanted guest would linger on throughout 2015. We all know El Nino is a bad guy who adversely affects the Indian Monsoons.

Well that was the bad news.

The good news? EQUINOO. You might say what on earth is that?

The full form is Equatorial Indian Ocean Oscillation. The so-called Indian Ocean Dipole (IOD). What is it?

It is a phenomenon that influences the Indian monsoon. It involves the Indian Ocean waters near the coast of Somalia and also near Indonesia. If the Somalian waters are warmer and stormier than the Indonesian waters then it is called a Positive IOD.

THE INDIAN OCEAN DIPOLE (IOD)

A positive IOD is good news for the Indian monsoons. And it is positive now. The coast near Somalia has been stormy for quite many days and it is likely to stay that way for many more days. (SEE FORECAST CHARTS BELOW)

So a bad El Nino might be nullified by a positive IOD and we will get a bumper monsoon.

Below are the Indian Ocean Dipole forecast charts for June, August and October 2015. They are expected to be most positive in October. Heavy rains then?