Thursday, 6 October 2016

Goa South West Monsoon 2016, The Final Analysis

The South West Monsoon Season 2016 in Goa, lasting from June 1 to September 2016 was normal this year. But the monthly rainfall showed wide variation in departure from Normal (%), except in the month of September.

Following Graphs and figures give a good picture of how the monsoon season unfolded in Goa this year.

Data is from IMD, Goa Center.

1) Daily Variation of Seasonal Rainfall (Graph from http://www.imdgoa.gov.in)


2) Monthly and Total Rainfall Figures June to September 2016:


3) Monthly Departure from Normal (%):


4) Seasonal Rainfall Recorded at major towns in Goa:





























Pernem in North Goa was the surprise wettest place in Goa this year. The usual wettest place, Valpoi, at the base of Western Ghats, received poor rainfall in June and as a result finished outside top five wettest places. Mormugao and Dabolim also made surprise appearance in top 5 places, mainly on account of strong showing in June.

5) Month-wise Seasonal Rainfall for Major Towns in Goa:



















6) Seasonal Rainfall recorded at Major Towns on Map of Goa:


7) Comparison of 2016 Seasonal Rainfall with past Years:





















From this graph we observe that during the last 4 years, except for the month of September, there is a great variation in the monthly rainfall amount YoY. Additionally, this year July lost the honour of normally being the wettest month of the year.

An excellent Final analysis of the performance of the SW Monsoon this year over India as a whole is given in the popular weather blog 'Vagaries of the Weather' at this LINK

According that analysis the Sub-Division of Konkan and Goa has the honour of being the wettest sub-division in the country this year.

The total All India Rainfall this year was in normal range finishing -2.87% below normal.

Though the official SW Monsoon season has ended, the withdrawal of the SW Monsoon has been limited to NW India till October 6, the date of writing this post.

Goa is expected to receive scattered light rainfall, till the monsoon withdraws completely by late second half of October.

Wednesday, 31 August 2016

Monsoon in Goa in August 2016 - Deficient rains bring the seasonal rains just below normal

The SW Monsoon continued its below normal performance from July into August 2016, but to a much greater extent.

Against a normal rainfall of 681 mm in August, Goa received just 497 mm this year showing a deficiency of -27%! 

This took the the seasonal rainfall this year from June 1 till August 31 to 2663.7 mm ( 104.9 inches) against a normal of 2691.5 mm (106 inches) i.e. -1% below normal from +8% above normal at the beginning of the month.

The SW Monsoon in Goa has continued to remain just around normal mainly due to the 35% excess rains it received in June '16, even though July rains were -13% below normal.


Inspite of the poor rains in August this year, the seasonal rains so far have performed better than in 2015 and 2013 and almost as good as in 2014, at this time of the year.

In the graph below, the rains for 2013 are for Panjim Center only, as IMD had not started the Average Weighted Area Rainfall for Goa that it adopted from 2014 onwards.


Overall in August this year there were just 6 days which had normal or above normal rains.

Source: IMD, Goa Centre
During August the interior areas, particularly at the base of western Ghats received heavier rainfall than coastal areas.


A number of rain centers crossed the 2500 mm and the 100 inch seasonal rainfall milestone in August.

Mormugao lost the top spot to Pernem and Valpoi and Sankhali continued to see late seasonal surge!



Though the S W Monsoon starts withdrawing from Rajasthan normally around September 5, Goa continues to experience fairly good monsoon activity throughout September.

The official SW Monsoon season ends on September 30, but the rains have been seen to be continuing in Goa and S India into October in recent years.

Though La Nina has been delayed, the overall deficiency is very low and a good spell of monsoon rains in September can turn the seasonal rainfall into excess!

So, we have a whole month to wait and watch!

Wednesday, 24 August 2016

Monsoon Rainfall in Goa crosses 100 inches mark - Posted August 24, 2016

After a long break of 10 days, SW Monsoon has again become vigorous over Goa since August 23.

This has given the final push for the Area Weighted Average Rainfall to cross the 100 inches milestone, on August 23, 2016.

Till 0830 hrs on August 24, 2016, Goa had recorded 101.4 inches (2576.1 mm) against normal of 102.1 inches (2593.4 mm) for this time, showing a departure of just -1% from normal.

The top five wettest towns have all crossed 100 inches.

Pernem          117.44 inches
Mormugao    114.54 inches
Sankhali        113.05 inches
Margao          102.39 inches
Dabolim         102.35 inches

August has seen heaviest rains in the interior areas of Valpoi, Sakhali and Pernem

El Nino has turned Neutral, but La Nina is expected only in later half of the year.

The monsoon season so far has been normal over India and as of August 23, 2016, is showing a departure of just -2% from normal.


Karala, Guajarat, Punjab, Harayana, and the NE States have received below normal rainfall, while Madhya Pradesh and Rajasthan have received excess. Rainfall has been normal over rest of the states.

The rainfall is expected to remain in the normal range for the rest of the season, as per IMD forecasts.

Monday, 1 August 2016

July 2016 - Monsoon turns laggard but stays overall above Normal!

Goa , received 13% less than normal rains in July 2016, but coming on the back of a bumper 35% above normal rains in June, the South West Monsoon has still managed to stay above normal for the Season so far by 8%!

As against normal rainfall of 1104 mm, July 2016 received just 948 mm, taking the seasonal rainfall from June 1 to July 31 to 2167 mm ie 85 inches.
In fact there were just 9 days with above normal rainfall in July, mainly due to the shift of the monsoon axis to the far north.
As per the records maintained by Vagaries Goa from the data published by IMD, Goa Centre, The rainfall in July 2016 is lower than that in July 2013 and 2014, but higher than in July 2015.


While the neighbouring coastal districts in North Konkan of Ratnagiri (1694 mm), Raigarh (1386 mm) and Sindhudurg (1255 mm) all figure in the top ten wettest districts of the country for July 2016, none of the two districts of Goa does, as per this post in the Blog Vagaries of the Weather.

The Top three wettest places in Goa in July were:

Pernem - 44.42 inches
Mormugao - 43.44 inches
Sankhali - 40.58 inches

Mormugao crossed the 100 inches mark for seasonal rainfall during July. Overall for the season from June 1 till July 31, 2016, the wettest places were:

1. Mormugao - 104.41 inches
2. Pernem - 97.27 inches
3. Dabolim - 93.33 inches

In Google Earth for geographic perspective and with rainfall in mm check this out:

India as a whole continues to have a good monsoon this year with the seasonal rainfall so far at the normal.


With half the monsoon season over and El Nino having ended, the rest of the season would appear to proceed in the normal path as per the latest forecast by IMD, released on August 1, 2016 and available here and extract from which is reproduced below:


We shall keep track of how the season unfolds in these very pages! Keep reading!

Thursday, 21 July 2016

Monsoon vigorous over Goa - Posted July 21, 2016

Goa has been experiencing heavy to very heavy rains since Monday, under the influence of a weak trough off the coast of Goa.

Area weighted average seasonal rain for Goa from June 1 to July 21, 2016 has reached 1890 mm (74.4 inches), which is 15% excess over normal, for this time.

Mormugao has a seasonal total of 2300 mm (90 inches) the highest in Goa so far.

Vagaries Goa rain gauge at Margao has recorded 85 mm each on Wednesday 20 and Thursday 21.

Heavy rains are expected to continue over parts of Goa over next two days.


(Source: http://www.imdgoa.gov.in)

Friday, 15 July 2016

Mid July 2016 - Monsoon takes a break!

After an explosive start in June 2016, when Goa witnessed one of the wettest month of June in recent years, (read this post), monsoon has slowed down in Goa and mid July, can be definitely said to be taking a break.

Meteorologists speak of the Monsoon axis having shifted far north towards Indian Plains and the base of the the Himalayas, as being the main reason for this beak. But this situation is expected to last at most for another week, before monsoon is supposed to resume with vigor.

Against normal rainfall of 512.70 mm, Goa has received just 394.1 mm during the first 15 days of July, showing a deficiency of 22%!

However due to the 35% excess rainfall received in June this year, the cumulative rainfall as measured from June 1, 2016, is still around 14% above normal!

Source: IMD Goa Center
The top three rain centres during the first half of July 2016 were:
1. Pernem - 23.14 inches
2. Sakhali - 22.48 inches
3. Valpoi - 20.91 inches

Poor rains during July first half, for the June leaders Mormugao and Dabolim, allowed Pernem and Sankhali to leapfrog over these coastal towns!

Top five centres with cumulative rain figures from June 1 to July 15, 2016 are:
1. Pernem - 75.99 inches
2. Sankhali - 71.76 inches
3. Mormugao - 71.14 inches
4. Dabolim - 67.24 inches
5. Sanguem - 63.52 inches

The monthly variation can be seen better in the following graph:

The monsoons have now covered the entire country. As of July 15, the rainfall was 1% above normal as whole for the country. Only Gujarat, Saurashtra, Bihar, Assam and Tripura have received deficient rains.


The satellite picture for July 15, 2016, too makes for happy viewing!


IMD has predicted that the SW Monsoons, will be good this year and the season may extend well beyond September!

Watch these pages as the drama unfolds!










Sunday, 3 July 2016

June 2016 - Monsoon performance over Goa

June 2016 saw Goa receiving the highest rainfall, amongst all other states in India, from both the pre monsoon and the actual South West Monsoons, even though the SW Monsoon was delayed and reached Goa only on June 10, officially.

Goa received area weighted average of 1215.9 mm (47.8 inches) of rainfall during this 30 day period, compared to 595.70 mm area weighted average rainfall for Kerala in the second place.

Thus Goa received nearly 35% above normal rains this year, which is also the highest total during June in the last 6 years.
Source: IMD, Goa Center




South Goa and North Goa also figure among the top five wettest districts of the country in June:
1. Udupi - 1322.00 mm
2. South Goa - 1307.80 mm
3. Sindhudurg - 1124.60 mm
4. North Goa - 1107.30 mm
5. Ratnagiri - 997.00 mm
(Source: The superb data presentation by GSB, at the website of the weather blog Vagaries of the Weather, which can be accessed by clicking on this link)

Mormugao and Dabolim centres topped with highest rain figures for June, mainly because of heavy pre - monsoon showers recorded. Surprisingly the the normally wettest place Valpoi received the lowest rainfall, as per IMD records.





















Coastal areas of Goa, generally got better rainfall than the interior areas.




















By June end SW Monsoon had covered almost the entire country. This year SW Monsoon is expected to be above normal for the country as a whole.


Of course we will continue to track the progress of the monsoons in the coming months!