Goa Monsoon 2014 Analysis - Happy Ending!

The South West Monsoon Season brings the bulk of the rains to Goa every year.

The Monsoon season lasts from June 1 to September 30th.

Monsoon season 2014 started with the scary prospect of deficient rains! There was a talk everywhere of an El Nino in August - September. And to compound the problem, arrival of the rains in Goa was delayed by 5 days. From June 1 to June 30 Goa received nearly 46% deficient rains. But it was the copious rains that Goa received in July and August which turned the tide! Check these blog posts for details of June 2014 Monsoon Analysis,  July 2014 Monsoon Analysis,  August 2014 Monsoon Analysis

In 2014 in the final analysis, from June 1 to September 30, Goa received Area Weighted Average Rainfall of 3057.2 mm (120.36 inches) against normal of 2971.7 mm (117 inches) showing a surplus of 3%! The pattern of rain during the four months is brought out in the IMD Goa prepared daily average rainfall graph in Figure 1, the Monthly Rainfall and total Rainfall graph in Figure 2 and the cumulative rainfall graph in Figure 3 below.

Figure 1

Figure 2

Figure 3

IMD Goa maintains daily records at 13 Rain Stations across Goa. It was again Valpoi at the base of the Western Ghats in the Eastern Interior Goa which retained the title of the wettest place in Goa for 2014! Valpoi received 4111.4 mm (161.87 inches) of seasonal rains. It was closely followed like last year by Sanguem, also at the base of the Western Ghats but more to the South. Sanguem received 3950.2 mm (155.52 inches) of seasonal rainfall. Margao, Canacona and Sakhali also made it to the top 5 wettest spots. See Figure 4.

Figure 4

The rains decreased from the interior towards the coast and the Port town of Mormugao with 2460.3 mm (94.74 inches) and the Airport town of Dabolim with 2337.8 mm (92.04 inches) occupied the bottom of the table. In fact these two places were the only places which did not cross the Century of Seasonal Rainfall in inches. Rest all places crossed 100 inches of rainfall.

A graphical depiction of the seasonal rainfall in Google Earth shows the variation quite well.

Figure 5

Rainfall in September 2014 was almost entirely restricted to the first half of the month.

Vagaries Goa Rain Gauge which is located at Margao brought this out well as seen in the daily rainfall readings in Figure 6.

Figure 6

The last few days of September witnessed  thunderstorms in the late afternoons associated with retreating monsoon. The thunderstorms which start in the interior from the east and proceed towards the west and the Arabian sea, brought increasing rainfall in the interior. Figure 7 shows the September 2014 rainfall pattern across Goa.

Figure 7

Margao monthly rainfall in Figure 8, is representative of the rainfall pattern this year across the state of Goa.

Figure 8

So even though the seasonal monsoon rains in 2014 were less than 2013, the fears of El Nino did not materialize and the copious rains in August were just enough to turn the deficit into a 3% surplus rainfall season for Goa!

Just for comparison Figure 9 shows the Sub-division wise average rainfall across India. Thus India as a whole showed a deficit of 12%! For a more detailed look at the performance of Monsoons in India for 2014 check this post at the weather blog www.vagaries.in.

Figure 9

Though the Monsoon season ends on September 30, the withdrawal of monsoon from Goa usually gets prolonged till mid October. And so the monsoon magic continues!

 

SW Monsoon is now withdrawing - posted September 29, 2014

The South west Monsoon has now started withdrawing from India beginning from west Rajasthan and progressively from Gujarat, west M.P., west U.P., The Punjab and the rest of the country.

IMD has officially indicated the withdrawal in the map below as on September 28.

Monsoon normally withdraws from Goa between Obctober 1 and 15. This year is no exception and during last two weeks Goa has been experiencing isolated thunderstorms in the late afternoons and evenings, typical of withdrawing monsoon.

The day maximum temperatures are expected to be around 33-35C with lower humidity than normal due to winds blowing from the East and North.

Likelihood of rains this week - posted Monday September 22, 2014

Goa continues to enjoy a fine mid September spell of occasional rains and plenty of sunshine as forecast in the last post !

However things may change later this week. Retreating monsoon season would see late afternoon and evening showers accompanied with thunder from Wednesday 24th onwards till around Friday 26th. This would be particularly true towards the hills in the interior of Goa. Coastal areas may experience overcast skies. As explained by the weather blogger Mr Rajesh Kapadia in his blog The Vagaries of Weather at http://www.vagaries.in  in THIS POST a Line of Wind Discontinuity (LWD) will form on 23rd from around Satara in Maharashtra to interior Karnataka, and a low will form at the same time in interior Karnataka. This low is expected to travel west and fizzle out in the Arabian Sea off the coast of North Karnataka.

Goa will be benefitting from the rains from this system!

Quoting further from the Blog Vagaries of Weather "Monsoon has withdrawn from west Rajasthan and Kutch and begin gradually withdrawing from Punjab and (rest of) Rajasthan by 23rd".

Goa has received normal rain with just 4% excess as seen in this graphic from http://imdgoa.gov.in

However overall deficiency for SWM 2014 over India remains -11%

Things are not expected to change much over rest of the monsoon season which officially ends on September 30!

Update September 15, 2014 - Monsoon Withdrawal Symptoms?

Update September 18,2014, 1800 hrs:

Break Monsoon like conditions returned on September 17 and Vagaries Goa recorded zero mm in 24 hrs ending 0830 September 18. Check here. September 19 saw heavy downpours in some parts mostly towards the interior, but largely the coastal belt remained dry. Vagaries Goa recorded zero mm during 0830 - 1800 on September 19.


Update September 16, 2014, 1800 hrs

 

As if to prove wrong the GFS forecast mentioned in the post below, most parts of Goa remained heavily overcast from September 16th morning and experienced scattered heavy downpours throughout the day. Vagaries Goa recorded 20 mm from 0830 to 1800 hrs on September 16th, and the rains continued at the time of this update. This development tied up with formation of low pressure area in westcentral Bay of Bengal and adjoining Coastal Andhra Pradesh and Associated upper air cyclonic circulation.

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Last year in 2013, September saw an almost dry period in Goa for the first 15 days, followed by one of the wettest 15 days period in September in recent years. Checkout this post on September 2013 Monsoon Revival

However this year in 2014, the last fortnight may well signal that the Monsoons are finally withdrawing.

GFS forecasts for Goa are all pointing to atleast a dry week ahead till September 21/22. The SW Arabian Sea winds are also weak with low moisture.

These Rains in First half of September have helped Valpoi cross the 150 inches mark and retain its role as the wettest place in Goa. Sanguem is however, not very far behind:

Mapusa, Mormugao and Dabolim are the only rain stations in Goa which have not crossed the Century rainfall mark in inches as of 15th September.

As of September 15, 2014 the Area Weighted Average rainfall for Goa has reached 2961.9 mm (116.6 inches) against normal of 2845 mm (112 inches), which is a surplus of +4% as on September 15!

You can check out the pattern of Rainfall in Goa from June 1 to September 15, 2014 in Google Earth and also monthwise graphically HERE

And you can check the daily rainfall pattern for my hometown Margao HERE

Are we going to end Monsoon 2014 in surplus after all? Watch this space!!

SWM 2014 a Review so far - posted September 6, 2014

The official South West Monsoon season in India lasts from June 1 to September 30. The forecasts for this year's SWM were grim, what with the possibility of La Nina being predicted to bring poor rains to the country.

We are now one week into September and with just three weeks to go before this year's SWM season ends, its worthwhile taking a look back on the SWM 2014 performance so far.

Weather Blogger Rajesh Kapadia has done just that and his blog entry dated September 6, 2014 at www.vagaries.in is reproduced in full below after the graphics below.

The graphics indicate that a super duper spell in late August across the length and breadth of India has brought the deficiency down to just -12% as on September 6. Most of the country has received Normal rains, while J&K and S.I. Karnataka have received excess rains. Orange colour indicates deficient rains. There are no sub divisions with scanty rainfall records as on September 6, 2014! However the situation can change if the rains take a break for a few days in September!

Till September 5, NW India was the worst performer followed by East & North East and Central India. Punjab, Haryana, H.P. and Delhi NCR along with Marathwada remain the worry areas. However the excellent rains in Karnataka as a whole, has helped South Peninsula to show a deficiency of just -5%!

For Goa the situation is much better as on September 6, than what it looked like earlier. June '14 end the deficiency was -49%, July '14 end the deficiency was -17%, but by September 6, 2014, Goa had received +4% more than normal LPA, mostly due to the extremely heavy spell in the last week of August!

As the article by Rajesh Kapadia reproduced below indicates we may have a better year than 2009 after all!

SWM 2014 thus far. An brief Review....6th September - By Rajesh Kapadia (www.vagaries.in)

From a threatening -47% down to -12% today. The country has received 655 mms against a normal of 765 mms till date. Thats the overall All India Monsoon Position. Thanks to massive rains in Jammu Kashmir and Punjab last few days, the overall deficit has come to almost reasonable and "civilised" levels.In fact, a few more % points reduction and the dubious label of "drought" will be wiped out. IMD considers a drought year if the deficit falls below -10%. Seems likely to be covered this year.
India normally receives 890 mms in the 4 months of SWM season as a long term average.
Situation is far better than the worst year 2009. That year, the deficit at the end of the season was -23%.
But, still there are a few areas of concern. Punjab, UP and Marathwada amongst them. I would put it like this: the situation in these few regions is still far from being "drought free".Marathwada may see very good rains next few days from BB-8.
However, thinking positively, the late surge of rains in Punjab and Rajasthan and NW India, will benefit the rabi season immensely. It will be saturating the soil with sufficient soil moisture.

But, the water position may not be as comfortable. The overall water reservoir stocks is below normal,except in Central India. North ndia, which has seen the maximum shortage of adequate rainfall, sees the stock of reservoirs at 79% ( 93% last year) of full capacity. Eastern India stocks show 68% (75% last year) of full capacity. Western India 70% (76%) of capacity and South India 68% (81% last year. Central India is the lone zone seeing better than last year levels at 74% (58% last year).
The Overall country average is 71% ( 87%) of capacity against full level.