Friday, May 02, 2014

Monsoon Watch -3 2014 (Additional)...May 2nd 2014

The enhanced convective phase of the Madden Julian Oscillation is located across the western hemisphere and is gradually propagating eastwards. 
The presence of ITCZ is  in the northern hemispheric near equatorial region as well as the rainfall peak which occurred over the south peninsula. Hence, ITCZ  seems to have crossed the Equator, 8 days ahead of the normal date.

A lull in the passage of western disturbances across north-west India aided in the increase in day maximum temperatures to rise to their near / above normal values over north-west & central India.


Jet Streams: The core was located around Lat. 28°N with the wind speed varying between 90-119 kts around 200 hPa.

The Important Parameter of the LWD formation in the Peninsula (bringing in required moisture) is also well formed. It is giving good adequate precipitation in the Southern regions (See map below ) 


(Pradeep's Page gives the daily figures)

SSTs are warming in the Arabian Sea to around 31c off the Goa and Kerala coast and 30c in the Lakshdweep Seas. Mumbai off coast SST was 29c on Saturday (last readings).. But, sooner than expected, we see strong North winds along the Somali coast, which has commenced the Somali Current effect. SSTs along the Somali coast is 24c. 
Today's SST map is reproduced here to show the Sea temperature not falling sufficiently yet along the Somali coast. It is presently just about around 24c in spots.


Now, this difference with the Central Arabian Sea plays a key role in cloud formations off the Western Coastline of India in the Central Arabian Seas. The SST along the Somali coast will rapidly fall to around 18/20c in the next 10 days.
More on Somali current  here: 

The arrival date (Below) is calculated seeing today's position. Further from today, we presume the normal rate of progress of the Monsoon Parameters. 

This initial estimated dates are subject to some changes, and will be finalised around mid-May, when the puzzle pieces look well arranged.

As of today, there seems to be a slight advancement in the dates  in the Arabian Sea. Bay Branches of the Monsoon seems to be on normal dates. There could  be a advancement on the arrival date of the Monsoon in the Arabian Sea branch.
Bay branch needs to wait a few days for the High to fizzle out, and to get going. 

Arabian Sea Branch: Though there is some improvement in most of the parameters, and most parameters are on time, and are +ve.

(Dates in brackets are the normal dates of arrival).

On these calculations, Vagaries would  maintain the Monsoon to reach Maldives around the 22nd of May 2014 (20th May), Sri Lanka around 25th/26th of May (25th May).
Kerala by the 30th/31st May (1st June).

Regular Pre Monsoon thundershowers ( almost daily basis)  could start from around 1st June in Goa and South Konkan, and 3rd/4th June in Mumbai. Outer townships and Ghat regions can get pre monsoon thunder showers by around 2nd June 2014.

Hence, maintaining and presuming the normal rate of progress, Goa should get Monsoon rains by around 5th June (5th June).

Monsoon set in Mumbai by around 8th/9th June (9th June). 




Bay Branch: SWM should hit South Andaman Sea around 15th.May (12th May), and rest Andaman Islands by 18th-20th May 2013. NE States could get the regular Monsoon set in by 1st/2nd June this year.

Generally moves up (normally) the Bay at a sustained speed, and Kolkata should see Monsoon arrival by the 9th of June.

We stop at this initial progress, and work out further region wise progress at a later date  (as is the usual practice in Vagaries' MWs).

These Dates are worked out and estimated as per my personal calculations and may not be used for commercial purposes.The dates are not binding on anyone and no responsibility is taken if used for any purposes.





8 comments:

vishwas shinde said...

Thanksss

vishwas shinde said...

Thanks for the giving monsoon araival date...

Rohit Ghule said...

Sir when would u talk about quantum of rain for the season?

emkay said...

Thanks a lot Rajeshbhai, will speak yo you tonite. So it seems initial phase mein "acchey din aaney waley hain".

sset said...

Just wondering....
By blessings of God/nature will miracle of Cyclone Laila (2008) repeat over TN/SE India? Intense drought/ heat is overtaking.. Clouds are in bay but failing to produce any measurable rains...

sam khan said...

Rajesh sir, Are there any chances of (cyclone) forming in the Arabian sea this month.

sset said...

2005 was last year of excess rain recorded over TN. After that NE monsoons always kept decreasing and in recent 4 years have almost shown vanishing trend - chronic drought. IMD says TN highest probability of drough - every alternate can be drought but in reality TN is having 3 years of sucessive drought if this 2014 rains fails.....???

Wasim Athar said...

Having a powerful thunderstorm right away now in kolkata rajesh sir prediction bang on target