Uncertainty Continues In Northern Indian Ocean Weather

MAY 21, 2017, SUNDAY

As the southwest monsoon marshals its forces for an Indian entry into Kerala, doubts remain as to what will be the arrival like. Will it be steady, undeterred by a tropical cyclone gulping away some of its moisture and stamina? Or will an Arabian Sea tropical cyclone snatch away some its momentum as it veers off tangentially to Oman?

A Bay of Bengal/Arabian Sea storm is beneficial for monsoon rains in India if the system makes landfall into the indian coast. It acts as a locomotive which pulls along the rains into the country. A cyclone going to Myanmar or Oman is not conducive for Indian monsoon. They suck away considerable amount of the monsoon's energy and from an Indian perspective counterproductive.

Meanwhile the numerical weather prediction (NWP) models are taking us on a wild goose chase. Not only are they not agreeing with one another but contradicting themselves in successive data output.

The GFS was indicating a Bay of Bengal storm yesterday, is predicting an Arabian Sea cyclone today. According to it the storm will start off as a low near the Kerala coast on May 30/31 then intensify into something awful and hit Oman by June 6.

Meanwhile even the stolid, European ECMWF with their much vaunted supercomputers too seem to be confused. Earlier it was predicting an Arabian Sea cyclone going to southern Oman/Yemen. Now it foretells a depression in the Bay of Bengal on May 31 near the Myanmar coast.

Presently the Indian Ocean is in a state of tremendous flux as the approaching rainy system is creating massive turbulence. The utter anarchy of nature is such that even the biggest man made supercomputers are unable to discern any pattern. Simply put the supercomputers cannot make head or tail out of the prevailing situation in the ocean.

That is why we are seeing ever changing contradictory forecasts by the NWP.

The GEFS (Global Ensemble Forecast System) believes monsoon will hit Mumbai on June 4, 2017

August 8, 2016: NOAA GFS Rain Forecast Maps, India

Related: Monsoon Forecast Update, August 8, 2016

August 8, 2016, Monday: The focus of attention is southern Rajasthan. The low pressure area will bring heavy rains to region and adjoining north Gujarat, Kutch in the coming days.

MICRO-LEVEL RAIN FORECAST FOR RAJASTHAN 

RAIN FORECAST TILL TUESDAY MIDNIGHT 

India NOAA 48 Hours Forecast Maps: August 7,8, 2016

NOAA FORECAST: TOTAL RAINFALL TILL TUESDAY, AUG 9, LATE NIGHT 

NOAA's GFS forecast expects heavy rains in parts of Madhya Pradesh spreading to southeastern Rajasthan till Monday morning as a result of the cyclonic circulation over Madhya Pradesh.

Heavy rains in southeast Rajasthan and parts of north Gujarat. The rain system which is now over Madhya Pradesh will move into north Gujarat-Kutch on Tuesday via southern Rajasthan.

European Forecast Model Hints At Heavy Rains In Andhra On June 8

JUNE 1, 2016

While the American GFS predicts heavy rains in Mumbai, Gujarat around June 10, 2016, the European ECMWF model is betting on Andhra Pradesh and Telangana on June 7-8.

It expects a low pressure area to develop on the Andhra coast on June 7, which will bring heavy precipitation to Andhra Pradesh, Telangana, Odisha and West Bengal.

Leading forecast models are thus disagreeing where the monsoons will change gears: West coast or east coast of India.

Keep in touch for updates.

LATEST NANAUK TRACK/PATH FORECAST: It will break up near Oman

XWF WEATHER PREDICTION MAP: Latest GFS forecast says Nanauk will not make landfall into Oman but dissipate mid-sea on June 16 (See the map)

Latest GFS forecast says the cyclone Nanauk will break up near the coast of northern Oman.

It will keep going towards Oman. It will reach the seas near north Oman on June 13, Friday. After that it will NOT MAKE LANDFALL. It will hover around then strengthen and then start moving first north and then northeastwards. It will then start breaking up and completely disintegrate by Monday June 16, 2014.

AS WE SAID BEFORE NANAUK IS TURNING OUT TO BE A VERY VOLATILE AND UNPREDICTABLE STORM. SO WE CAN EXPECT ANYTHING IN THE NEXT 48 HOURS.

The JTWC Predicts A Big Storm But Other Forecast Models Doubtful

The JTWC center has already declared the Arabian Sea storm as a tropical cyclone 02A. It further says that it is going to be a big storm. 

But in its bulletin it also says...

LIMITED NUMERIC MODEL GUIDANCE IS IN FAIR AGREEMENT WITH THE WESTWARD TRACK WITH SOME SLIGHT DIFFERENCES IN TRANSLATIONAL TRACK SPEED. BASED ON THIS, THERE IS LOW CONFIDENCE IN THE FORECAST. 

Put it simply it means that few forecast models agree that the storm is going to go westward towards Oman. Also forecast models disagree on the winds this system is going to throw up. So the JTWC itself says "....Based on this, there is low confidence in the forecast".

We have wait for what the JTWC says in its further bulletins to know how things stand. Further bulletins will be issued at 9 AM, 3 PM, 9 PM today and 3 AM tomorrow (all times GMT). We will keep updating you.

What do the major forecasts say?

GFS: It says the storm will intensify for a day or two then weaken. Then it will intensify again and then weaken into a low pressure area when it touches north Oman.

ECMWF: The storm will intensify a little and go NNW towards Gujarat and dissipate in 2-3 days.

CMC: The storm will intensify a little and go near the Gujarat coast then weaken into a low pressure area which will potter around in the sea.

NAVGEM: The storm will intensify into a tropical cyclone and hit north Oman on June 14, Saturday.

So, as things stand there is confusion and disagreement on what is to become of the present Arabian Sea storm. 

This storm has really left the weatherman totally confused. Is it why the met departments of different countries are keeping mum? Silence is golden, eh!

GFS: Cyclone Nanauk To Hit Oman Friday 13; ECMWF: Depression Will Break-up Mid-Sea

ARABIAN SEA STORM UPDATE: MONDAY, JUNE 9, 2014, 1100 AM GMT

The GFS forecast: The tropical storm thundering along on Wednesday, June 11, 2014

That is the story of the present Arabian Sea low pressure area.

On one side the GFS forecast says the low pressure area will develop in a tropical cyclone which on Wednesday will have howling winds of 100 Kph. The storm will then weaken and touch Oman on Friday, June 13, 2014. Weakened but even then it will pack a punch with strong winds and lots of rains.

On the other side is the venerable ECMWF forecast. Both the BBC and IMD follow its forecasts. The ECMWF forecast model says a deep depression will emerge from the present low pressure area and move north. But a few hundred kms from the Gujarat coast it will disintegrate. There will be no impact on Oman.

Hence the confusion. Who will be proved right? The GFS? Or BBC/IMD brigade with their ECMWF basis?

The coming days will tell.

What do we believe? We tend to be partial to the GFS model.

XWF-GFS rain prediction map: Accumulated Rainfall recorded from now till June 16, 2014 owing to Nanauk. The figures are in inches

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The Met Office Arabian Sea Storm Track/Path

 MET OFFICE TROPICAL CYCLONE GUIDANCE FOR NORTH INDIAN OCEAN

             GLOBAL MODEL DATA TIME 00UTC 09.06.2014

    TROPICAL STORM DEVELOPED IN THE MODEL ANALYSIS AT POSITION : 12.7N  66.8E

  VERIFYING TIME     POSITION     STRENGTH        TENDENCY

  --------------     --------     --------        --------

 00UTC 09.06.2014  12.7N  66.8E     WEAK

 12UTC 09.06.2014  14.1N  69.1E     WEAK        LITTLE CHANGE

 00UTC 10.06.2014  15.2N  68.6E   MODERATE  INTENSIFYING RAPIDLY

 12UTC 10.06.2014  16.4N  68.0E   MODERATE      LITTLE CHANGE

 00UTC 11.06.2014  17.3N  67.7E   MODERATE   WEAKENING SLIGHTLY

 12UTC 11.06.2014  18.4N  67.2E     WEAK     WEAKENING SLIGHTLY

 00UTC 12.06.2014  19.4N  66.9E     WEAK     WEAKENING SLIGHTLY

 12UTC 12.06.2014  BELOW TROPICAL STORM STRENGTH

Low pressure area to form in south Arabian Sea today. Birth of Cyclone NANAUK?

THE LOW PRESSURE AREA FORMS ON JUNE 8, 2014

The much dreaded low pressure area will form in the southern Arabian Sea on Sunday, June 8, 2014. Why I say dreaded is because such a system forming at this time of the year usually means trouble. Read that as a big bad cyclone.

I write this update with some confidence because three forecasts, GFS, CMC and NAVGEM confirm the formation of the low pressure area.

CMC and NAVGEM say outright that cyclone Nanauk is coming. The dates differ. NAVGEM says the cyclone is going to hit Oman on June 13, 2014. CMC gives a latter date.

The more trusted GFS model confirms the formation of a low pressure area but does not confirm that it will turn into a cyclone. Let us see what it says later.

June 11, 2014. The NAVGEM forecast model shows cyclone Nanauk hurtling towards Oman. 

Low Pressure Area May Grow Into A Cyclone In Arabian Sea: Or Monsoons Hit Mumbai June 15, 2014

June 13, 2014. The Arabian Sea Tropical Storm About To Hit Oman

A low pressure area has been spawned in the Arabian Sea. Area is 5 Degrees North, 68 Degrees East. This looks ominous. The timing is right. June. As we have said before the month of June is one when the North Indian Ocean gets restless and throws out a cyclone.

And when a low pressure area develops in the Arabian Sea in June. That spells trouble. The reliable GFS forecast seems to confirm our worst fears.

Yes.

A big bad storm has just been born. And the GFS forecast says it is going to grow into a big mean tropical storm. Where is it going to go? Oman.

The GFS forecast says that the low pressure area will gradually start moving northward along the Indian coast and gradually gain strength. Around the 10th of June, 2014, it will suddenly swing NW and hit Oman on June 13, 2014. The province which will face the brunt of the storm is Ash Sharqiyah.

May be Cyclone Nanauk is coming. After all.

But a word of caution. It is early days. The low pressure area may just fizzle out without developing into a significant storm.

Exploring this scenario further, if a storm fails to form, the monsoon system will move gradually up the Indian west coast and bring rains to Mumbai on June 15, 2015.

We will give you the latest forecasts and confirmation (Or otherwise) from various international sources.

Alternative scenario: No storm in Oman but monsoons reach Mumbai on June 15, 2014.

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MORE RAIN PREDICTION MAPS

 Alternative 1: Tropical storm hits Oman on June 13, 2014

Alternative 2: Monsoons hit Mumbai on June 15, 2015

Two Models Say: The Indian Ocean May Well Throw Up A Tropical Storm In First Week Of June

As we said earlier the southern Arabian Sea is in ferment. Two forecast models say the mass of clouds will throw up a tropical storm.

The CMC model says that a low pressure area will form in the southern Arabian Sea between the Horn Of Africa and Sri Lanka on June 1, 2014. This will then over the next few days intensify into a massive cyclone. It is expected to move in a WNW direction. It is the direction of northern Yemen-Southern Oman border. We have talked about the CMC forecast earlier.

The NAVGEM model says a low pressure area will form in the same area (8 Degrees North, 65 Degrees East) On June 2, 2014. What happens next? Latest (May 29, 2014, 1500 Hrs.) forecast from NAVGEM says it is going to be a full blown cyclone which may go anywhere. But it is generally agreed that the model is about 40% accurate. We will keep a close watch and keep you updated.

The god of all forecast models, the GFS, does not support these predictions. For now. Our hunch is the storm, weak or strong, will head towards the Gulf of Aden. Let us wait for further developments.

The big storm as predicted by the CMC Model on June 3, 2014. Seems to be a big storm.

The NAVGEM Model says it is going to be a full-blooded cyclone. Latest forecast map (May 29, 2014,  1500 Hrs.) shows the predicted position on June 5, 2014.

Satellite image of the Arabian Sea taken at 00.00 Hrs. GMT, May 30, 2014