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North India 2014, much dust, more heat, late rain

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The sweltering of North India, aggravated by manic urbanisation, just as manic use of personal automobiles, the steady thinning of tree canopies, and small businesses forced to buy diesel generators – in the tens of thousands, each emitting hot fumes that further trap already heated layers of sooty air – is an annual pre-monsoon epic that no-one has the energy to write.

This panel of four maps shows us where India baked during the last week of 2014 May (and now, Delhi has experienced a record its residents did not want). The high temperature belts (top left map), 40-45 Celsius, covered most of central and north-western India (Maharashtra, Madhya Pradesh, Gujarat, Rajasthan, Gangetic Uttar Pradesh, Haryana, Punjab and Delhi). Minimum temperatures (top right), 20-15 Celsius, are seen in two pockets – south interior Karnataka and in the North-East over Manipur and Mizoram.

These temperature maps may be read with the rainfall for the same period, 2014 May 25-31, to correlate particularly the temperature anomalies (how much higher or lower the normal maxima and minima have departed) with where it has rained. The rainfall map (lower left) shows rain having fallen over south Karnataka, but also north West Bengal and eastern Bihar, coastal Odisha and southern Haryana. These appear to relate to a group of anomalies (lower right): the first being interior Tamil Nadu, north-eastern Karnataka and adjacent Andhra Pradesh; the second being eastern Uttar Pradesh and adjacent Bihar. [You can get the four maps in this zip file.]

Read these from top left - 21, 22 and 23 June. Lower row - 24, 25 and 26 June. The green shading is the rain-bearing cloud cover. After 20 June the peninsula will have rain in most meteorological zone but North and north-west India will still await the monsoon system.

Read these from top left – 21, 22 and 23 June. Lower row – 24, 25 and 26 June. The green shading is the rain-bearing cloud cover. After 20 June the peninsula will have rain in most meteorological zone but North and north-west India will still await the monsoon system.

What these don’t show, but which the longer range forecast Indian Institute of Tropical Meteorology (Pune, Maharashtra) has on record, is that monsoon 2014 will not touch northern India until the fourth week of June. Rain-bearing cloud and wind systems will cover, in this forecast, peninsular India by around the 16th or 17th of June, but it will be another week before they deliver some relief to the cemented and asphalted surfaces of the National Capital Territory and its parched surroundings.

These very helpful maps are used by the Pune-based met researchers as part of their monsoon monitoring and forecasting partnership with several international climatoloigcal research institutes, chief amongst them the National Oceanic and Atmospheric Administration (NOAA) of the USA through its Climate Prediction Centre.

The Tropmet – as the Pune group is usually called – has bequeathed to us a definition (perhaps for this season only, subject to revision when climate change asserts itself) of monsoon rain that is in part scientific and in part geographic, which I think is a good sign (the Indian Meteorological Department will disagree, but we know better). The faster Tropmet decides to communicate in language appreciated, and understood, by Bharatiya citizens, the more said citizens will find an interest in correcting the misconceptions of scientists.

Tropmet says: “Rainfall within the summer monsoon season is mainly punctuated by the northward propagating monsoon intraseasonal oscillations (MISOs) with timescales of 30-60 days that manifests as spells of heavy rainfall and periods of quiescent rainfall, instead of a continuous deluge.” In the Konkan, we like our continuous deluge and the old-timers would have sixteen names for different sorts of deluge (and an equally rich chest of monsoon nouns for other sorts of rain).

Preparing for Cyclone Phailin

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RG-Phailin-eastern_India_rain_peak_201310Update4: The water carried over land by Cyclone Phaillin has now travelled northwards and west. Daily monsoon system monitoring by the Centre for Ocean-Land-Atmosphere Studies – COLA (a scientific research centre to improve understanding and prediction of Earth’s climate variations) now show the danger from very heavy rain to districts in interior Odisha, eastern Madhya Pradesh, Chhattisgarh, Jharkhand, Bihar and eastern Uttar Pradesh.

The soil moisture in these regions is already high – as it should be at the end of the south-west monsoon – and very heavy spells of rain approaching 20mm in three hours will cause widespread flooding. The National Disaster Management Authority and the armed forces will continue to have to be on the alert for flood-related rescue calls from these regions.

Update3: It is very worrying to find that:

(a) satellite images shared by a global meteorological community are showing that Cyclone Phailin crossed the Indian coast between 1800 and 1900 (6pm and 7pm) but until well after 1900 (7pm) the Indian Meteorological Department told television news channels it was still approaching, and

The NOAA image dated 12 October 2013 and timed at 1400 UTC which shows the eye of Phailin having crossed the Indian coast in Srikakulam district, Andhra Pradesh.

The NOAA image dated 12 October 2013 and timed at 1400 UTC which shows the eye of Phailin having crossed the Indian coast in Srikakulam district, Andhra Pradesh.

(b) that hourly data from the automated weather stations on the eastern coast are not visible – no explanation as to whether they had been knocked out by the cyclonic conditions or whether the data links were down.

Update2: The armed forces and para-military and disaster relief and rescue teams are reported to be ready. Two Indian Air Force IL-76 aircraft have taken teams and equipment to Bhubaneshwar, Odisha. The Indian Air Force is on stand-by at various bases including Raipur, Nagpur, Jagdalpur, Barrackpore, Ranchi and Gwalior. At least 28 teams of the National Disaster Response Forces have been mobilised.

Fishermen moving fishing boats (above) to safe places following a warning about Phailin cyclone in Srikakulam district. Photo: The Hindu/Basheer. The Phailin data sheet at IST 1100 on the Tropical Storm Risk website (below).

Fishermen moving fishing boats (above) to safe places following a warning about Phailin cyclone in Srikakulam district. Photo: The Hindu/Basheer. The Phailin data sheet at IST 1100 on the Tropical Storm Risk website (below).

The East Coast Railway has cancelled or re-scheduled passenger trains between Visakhapatnam and Bhadrak on the Howrah-Chennai Main Line route, PTI News has reported. Among these trains are Puri-Cuttack-Puri passenger, Paradeep-Cuttack passenger, Cuttack-Paradeep passenger, Puri-Gunupur-Puri passenger, Puri-Rourkela passenger, Puri-Cuttack passenger, Bhadrak-Cuttack-Bhadrak passenger and Cuttack-Palasa-Cuttack passenger trains.

PTI News has reported that Odisha has opened control rooms for the cyclone. The helpline number of the Odisha Central Control Room is 0674-2534177
The district control room numbers are: Mayurbhanj 06792-252759, Jajpur 06728-222648, Gajapati 06815-222943, Dhenkanal 06762-221376, Khurda 06755-220002, Keonjhar 06766-255437, Cuttack 0671-2507842, Ganjam 06811-263978, Puri 06752-223237, Kendrapara 06727-232803, Jagatsinghpur 06724-220368, Balasore 06782-262674, Bhadrak 06784-251881.

In Odisha, 200 trained ham radio operators have been put on alert to help with rescue work. Eight stations have been put on ‘active alert’ while there are 28 stations as back-up around India.

Via Twitter:
Google Person Finder has readied a service in response to cyclone Phailin to help find friends and loved ones (thanks to @GautamGhosh)
Phailin is forecast to strike at IST 1730 (5.30 pm) local time. Trust Foundation has a status page (thanks to @nitabhalla)

Also consult the Tropical Storm Risk site for frequent updates on the course and strength of Phailin.

Update1: For those in coastal Odisha and Andhra Pradesh, check TV and radio broadcasts for weather alerts and conditions in your district for as long as there is electricity. The government weather websites – India Meteorological Department and Mausam – have become very unresponsive probably due to high traffic.

Use the #Phailin hashtag on Twitter to find news and alerts near where you are. See useful examples like these:
Odisha Control Room numbers: Ganjam 06811-263978; Puri 06752-223237; Kendrapara 06727-232803 (thanks for this info to @aditya_manocha )
@debasis3: “Here we go. Rains have started in Bhubaneswar”
More Odisha Control Room numbers: Balasore 06782-262674; Bhadrak 06784-251881; Mayurbhanj 06792-252759; Jajpur 06728-222648 (thanks for this info to @ketan72 )

A new map of Phailin and its possible pathways from the Global Disaster Alert and Coordination System (GDACS)

A new map of Phailin and its possible pathways from the Global Disaster Alert and Coordination System (GDACS)

Important advice from the National Disaster Management Authority of India – If you are in the cyclone danger zone: check the house; secure loose tiles. remove dead wood or dry branches close to the house. Anchor movable objects like piles of wood, tin sheets (these are deadly when sent flying during a cyclone), loose bricks, rubbish bins (whose lids can fly like dangerous missiles in high wind), unbolted sign-boards.

Keep a few wooden boards, nails and a hammer ready to board up glass windows if they are in danger of shattering inwards. Keep emergency lighting ready. Ensure mobile phones are charged. Keep battery-operated torches ready batteries handy. Store boiled or filtered water for drinking. Keep dry food (such as biscuits) at hand if conditions worsen and you can’t cook a hot meal.

Zee News (television and online) has reported that in Odisha “thousands flee to shelter homes stocked with emergency food supplies and medicines”. National Disaster Response Force (NDRF) teams have reached Bhubaneswar (capital of Odisha) as evacuations have begun in Odisha and north Andhra Pradesh. Union Defence Minister A K Antony has asked armed forces to be ready to move in to Odisha and Andhra Pradesh.

NDTV (television and online) has reported that five districts “are preparing for the worst impact of the cyclone: Srikakulam in Andhra Pradesh and Ganjam, Puri, Khordha and Jagatsinghapur in Odisha.” Helicopters and food packages are ready for areas that are likely to be worst hit. A minister in the Andhra Pradesh state government has reportedly said that 64,000 people are being evacuated from Srikakulam, Vishakhapatnam and Vizianagaram and are being shifted to cyclone shelters.

The forecast six-day path of cyclone Phailin.

The forecast six-day path of cyclone Phailin.

The state of Odisha is preparing for Cyclone Phailin as it approaches from the Bay of Bengal. Consult the new map of Phailin and its possible pathways from the Global Disaster Alert and Coordination System (GDACS).

My reading of the forecast path of the cyclone – using the map sets from the National Centre for Medium Range Weather Forecasting (Earth System Science Organisation, Ministry of Earth Sciences) – is that in Odisha the districts of Ganjam, Puri, Jagatsinghpur, Kendrapara, Bhadrak, Baleshwar, Kordha, Jajapur, Cuttack, Nayagarh and Gajapati will be in the cyclone’s path beginning with increasingly heavy rain and fierce winds from Saturday morning 12 October 2013; in Andhra Pradesh the districts of Srikakulam, Vizianagaram and Visakhapatnam and in West Bengal the districts of Purba Medinipur will be in the cyclone’s path.

RG-Cyclone_Phailin_day3_sectionThe series of stacked rainfall forecast maps above show the approach of Cyclone Phailin from 11 October.

Look for the deep blue circle in the left panel from the first pair (top left, 24 hours) – extending out ahead of the cyclone core is the rain storm, which will cross the northern coast of Andhra Pradesh. In the second pair (top middle, 48 hours), the blue circle has moved closer to the coast – rainfall from the vast gyre of clouds around the approaching cyclone will extend far inland, in a great spike through Andhra Pradesh, parts of Madhya Pradesh and north into western Uttar Pradesh.

In the third pair (top right, 72 hours), the cyclone has made landfall with Odisha in the centre and affected districts in Andhra Pradesh to the south and West Bengal to the north – this is when the disaster management teams in the districts will be taxed to the utmost, having already been battered by heavy rain and unrelenting high-speed winds for two days.

RG-cyclone_districts_20131011In the fourth pair (lower left, 96 hours) the cyclone is still very active as it moves north-west to sweep across Odisha. In the fifth pair (lower middle, 120 hours) the cyclone core has finally weakened (no longer coloured deep blue) but has moved into Jharkhand, Bihar, West Bengal and eastern Uttar Pradesh. In the sixth pair (lower right, 144 hours) the cyclone’s force has dissipated leaving rain in its wake across eastern India.

Orissa Dairy has reported (‘Phailin upgraded to super cyclone’): “The very severe cyclonic storm Phailin, expected to make landfall at Gopalpur in Odisha, moved closer to the state and lay about 600 km southeast of Paradip, as the government sought the help of defence forces to boost its preparedness, official sources said on Thursday night.”

RG-Cyclone_Phailin_day4_sectionThe Hindustan Times has reported (‘Cyclone Phailin: deep depression over Bay of Bengal intensifies further’): “A morning bulletin of Bhubaneswar meteorological department on Friday said the cyclone would move north-westward and cross Andhra Pradesh and Odisha coast between Kalingapatam (Andhra Pradesh) and Paradip, close to Gopalpur, by Saturday evening as a very severe cyclonic storm with a maximum sustained speed of 205-215km per hour.”

DNA has reported (‘Odisha braces for Cyclone Phailin’): “The state government said it was making adequate preparation to deal with the disaster that expects to cause large scale devastation mostly in state’s coastal southern districts. Durga puja festivities in Odisha have been cancelled as the state prepares for Cyclone Phailin which could be the worst since 1999 when 10,000 people died. The Air Force, Navy and national disaster management team have already been put on stand-by, while the rapid action force has deployed its forces on the ground. People in the low lying areas of the state will be evacuated by Saturday evening.”

Monsoon mysteries, mundane mathematics

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Rainfall averages for the months of January to August 2013, nicely arranged in one handy panel.

Rainfall averages for the months of January to August 2013, nicely arranged in one handy panel.

June, July and August 2013 are behind us and India’s understanding of the south-west monsoon – and also of climate change during monsoon and outside the monsoon months – has scarcely improved.

Other than the announcements from the Indian Meteorological Department, which are unintelligible to anyone with even the smallest interest in monsoon and climate, there is little in India’s media or from official sources that helps turn an embarrassing scarcity of understanding into knowledge.

The IMD, I was told about two years ago by a senior crop scientist, is queried every day by officious underlings from New Delhi wanting to know weather conditions for wherever their bosses are to visit, and this means the ministers of the cabinet, sundry senior and junior ministers, all variety of politicians and all their scheming cronies and hangers-on. That is why the IMD has so many special forecasts for New Delhi on its website. For the Indian Meteorological Department, India outside Delhi seems to be an annoyance.

IMD-rainmap_imagedummyThere are science institutes, such as the Indian Institute of Tropical Meteorology, which is, as far as I can make out, the seat of the scientific inquiry into monsoon and climate. The communication about its work however is either dismal or absurdly comic. Scientists long ago realised that to be of use to society, they had to make their questions and answers understood by those whom they wish to serve.

In such a spirit, India’s monsoon and climate scientists and researchers ought to have begun their careers with a session before their grandmothers – could they explain their work to their grandmothers? If not, they ought not to have been accepted in their present jobs (and their grandmothers should be inducted instead, for the wealth of their traditional knowledge).

And this is why we have gobbledygook such as this – from the IMD, about the 2013 September forecast:

“The 5-parameter PCR model was also used to prepare probability forecasts for the pre-defined 3 (tercile) categories of rainfall during the second half of the monsoon season. These are below normal (<90% of LPA), near normal (90-110% of LPA), above normal (>110% of LPA). The tercile categories have equal climatological probabilities (33.33%  each).  The  forecasted  probabilities  for  the  September  2013  rainfall  over  the country as a whole in percentage for the above tercile categories are  31%,  53%, and 16% respectively.”

Can the Director General of Meteorology – who is the head of the IMD – explain this to his washerman, his gardener and the chap who sells him vegetables? If not, he ought to make way for someone who can, because India understands the DG of M not at all, and we’re not paying his salary and departmental budget from our taxes to be misspoken to about the rain.

Just so that you know, this verbally challenged gentleman is assisted in his duties by five Additional Directors General and by 20 Deputy Directors General. And when I examined where this chatty group is deployed, the Delhi obsession (or fear thereof) became immediately clear, for of the five Additionals, four are in Delhi (the fifth is in Pune), and of the 20 Deputies, ten are in Delhi (the others are over the capital’s horizon, toiling somewhere in the torpor of the sub-continent.

The IMD runs six regional meteorological centres – each ruled by a humourless Deputy Director General, all morbid conversationalists – and these are to be found at Mumbai, Chennai, New Delhi, Kolkata, Nagpur and Guwahati. Then the IMD has what it importantly calls ‘operational units’: meteorological centres at state capitals, forecasting offices, agro-meteorological advisory service centres, flood meteorological offices, area cyclone warning centres and cyclone warning centres. All important centres, all equally incoherent about their work, all equally clueless about how to speak simply with those who need the forecasts the most.

But the disease of obscurantist climatic communication is to be found also in the Indian Institute of Tropical Meteorology, to wit: “However, the extended range predictability arises from Monsoon Intraseasonal Oscillations (MISOs) which are the quasi-periodic northward propagating large-scale convective cloud bands that manifest as the active/break spells, as described earlier.”

What will it take to get these scientists and researchers to understand that monsoon, rain, weather and climate are of great interest to most adults amongst the country’s 1.25 billion-strong population, and that by mumbling only to each other in equations and formulae they continue to do us a mis-service, and in fact shirk their main duty?

The 6 June water event that our planners have missed

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This was in January 2013, in Mysore district, Karnataka. Can these women even reach the little island today?

This was in January 2013, in Mysore district, Karnataka. Can these women even use their coracle today?

In just under six weeks from today, the water available per head in India from our major reservoirs will drop under the 100 litres per day mark. This will happen on or around 06 June 2013, give or take a day.

Two charts with water levels for half the 84 major reservoirs, early February to late April 2013. Data taken from CWC

Two charts with water levels for half the 84 major reservoirs, early February to late April 2013. Data taken from CWC

For India’s 59 cities with populations of over a million (this will be so in mid-2013, see ‘India in 2015 – 63 million-plus cities’) this will mean an ever more frantic and dangerous race to secure water stocks by urban water mafia, who plunder public water storage and groundwater aquifers alike.

In the largest of these cities, their water boards claim to supply between 160 and 200 litres per capita per day (lpcd). This amount is roughly in line with what residents in comparably large East and South-East Asian cities are supplied, and is well above the lower end (100 lpcd) offered by the World Health Organisation as the minimum ‘optimal’ daily water stock required by an individual to maintain health and hygiene (100-200 lpcd is the band).

That’s the WHO view, but even in the Tenth Five Year Plan (2002-07) it was recommended that in India’s largest metropolitan cities the minimum must be 150 lpcd and in large non-metro cities the minimum must be 135 lpcd.

But six weeks from now, judging by the rate at which water has been used in 2013 from the 84 major reservoirs, we are not going to have, per head per day, even 100 litres of water. (Also see ‘Big dams, scarce water, thirsty India, uncertain monsoon’.)

Two more charts with water levels for the rest of the 84 major reservoirs, early February to late April 2013. For both sets of charts, the trendlines describe water volume as a per cent of the full reservoir volume. Data taken from CWC

Two more charts with water levels for the rest of the 84 major reservoirs, early February to late April 2013. For both sets of charts, the trendlines describe water volume as a per cent of the full reservoir volume. Data taken from CWC

How did we get here, so quickly and so dry? On 14 February 2013, the total water stored in the 84 major reservoirs was 68.718 billion cubic metres (bcm). Over the next ten weeks, until 25 April 2013, that total has dropped steeply to 42.304 bcm.

The Central Water Commission monitors the levels of and volumes in these 84 reservoirs, which if they all were full would store 154.421 bcm. These 84 reservoirs, says the CWC, represent 61% of the country’s water stored in reservoirs, which is altogether 253.388 bcm.

Judging by the same rate of water drawal from these 84 reservoirs, we have used over 43 bcm from all reservoirs in ten weeks, depleting our reservoir stock from 112.6 bcm to 69.3 bcm. This also means that in early February 2013, each of us were (notionally) holding a water stock of about 247 litres per day, a stock that was shrinking at a rate of about 1.3 litres per day to reach 152 litres per day in late April. And remember this is notional water stock per head from reservoirs, water that is used for agriculture and industry too.

What will happen between now and 06 June, when that individual stock drops under 100 lpcd? The Indian Meteorological Department has claimed (the usual bland and bored claim, as if monsoon was just another filing cabinet) that we will have a normal monsoon. As usual, the IMD has made no effort to link water with our alarming depletion of litres per head per day (it does link monsoon with GDP though, typically correct politically, typically unconcerned about human, animal and ecosystem need).

And what if the monsoon is late, scanty or erratic, as has happened with every monsoon since 2009? The IMD doesn’t know, your city’s PWD and municipality don’t know. But the water mafia do, and they’re getting very busy.

Written by makanaka

April 27, 2013 at 18:06

What ails the South Asian monsoon?

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Rainfall in India’s meteorological sub-divisions for the 2012 monsoon. The India Meteorological Department (IMD) has finally admitted that this year will be a drought, as it has forecast rainfall for August and September as “below normal”. Map: IMD

This set of images helps explain the worrying 2012 monsoon season in South Asia and why drought conditions are emerging in more districts with every passing week.

We are coming up to the eight-week mark of the 2012 monsoon (taking the 04-06 June date as the ‘normal’ for the monsoon to become active over south-west India, after which the climatological system slowly advances over the peninsula and up into northern India).

The Indian Meteorological Department (IMD) has not helped, by maintaining a scientific detachment between forecasting science and the dire situation of farmers and consumers. With emergency drought programmes new being rolled out in many states (more than a month late), the IMD’s refusal to speak plainly to those who need the information the most is unpardonable.

Worse, the Department on its website and its communications walls off its forecasting behind a very unfriendly science interface (see this commentary for a detailed explanation), and appears oblivious about its responsibilities to those for whom it exists – the citizens of India who are waiting for rain.

This set of images (strips below, you can click on the images for the full-size versions) describes what the IMD ought to be disseminating (but stubbornly refuses to). These are 24, 48, 72 and 96 hour regional forecasts for South Asia of accumulated precipitation and temperature extremes.

Day 1 – 02 Aug 2012

Day 2 – 03 Aug 2012

Day 3 – 04 Aug 2012

Day 4 – 05 Aug 2012

The four regions you see in the panels are Peninsular India and Sri Lanka, Western India and Pakistan, Northern & Central India and Nepal, and Eastern India and Bangladesh. These are from the monsoon forecasting sub-site of the Center for Ocean-Land-Atmosphere Studies – of the Institute of Global Environment and Society (IGES) – which processes and synthesises data from the NOAA/NCEP, which is the National Oceanic and Atmospheric Administration (NOAA, the US government agency), National Centers for Environmental Prediction. These regional weather forecasts are presented as a running four-day ensemble of images showing daily forecasts of 2-metre temperature minima and maxima and accumulated precipitation covering the four sub-regions.

Will it or won’t it? India’s monsoon forecast gamble

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Assam flood refugees. Photo: Alertnet

The India Meteorological Department (IMD) has released the long-awaited update of its long range forecast for the 2012 monsoon.

Stripped of its scientific jargon, this is what the update has said. There is a July model and an August model. For both months, there are three forecast categories: below normal in which rainfall in less than 94% of the long period average (LPA), normal in which the rainfall is between 94% and 106% of the LPA, and above normal in which rainfall is more than 106% of the LPA. Under the three categories, the forecast probabilities for July are (in the same order) 36%, 41% and 23% and for August they are 42%, 36% and 22%. Under any combination of probability therefore, this means that both July and August are going to be drier than usual, and coming on top of an unusually dry June, the scenarios for water availability and for agriculture come early September are all looking tough.

Arunachal Pradesh district rainfall for three weeks

The volatility of the 2012 monsoon over north-eastern India can be seen in the images of the district weekly rainfall deviations for those states. Please bear in mind that with the late beginning of the 2012 monsoon, the week of June from 07 to 13 was for all practical purposes the first monsoon week. The colours signify major deviations – red for 50% of the average and below, green for 150% of the average and above. In Arunachal Pradesh, for the first week the average rainfall in districts was around 45%, the second week it was 41% and the third week it shot up to 124% – red is evenly scattered through the districts in the first two weeks and green districts appear in the third week.

Assam districts rainfall for three weeks

In Assam, the first week’s average for all the state’s districts was 65% of the long period average, with red dominating. In the second week the average was 103%, with ‘red’ districts declining and a few greens appearing. In the third week the average zoomed to 184% with most districts being ‘green’. In neighbouring Meghalaya, the average for the districts in the three weeks was 63%, then 51% and then a steep rise to 225% in the third week. In stark contrast Nagaland and Manipur have for the duration of these three weeks seen a combined district rainfall average of 33% and if we remove the ‘green’ districts from both states of the third week, we get a dismal 15% average – it is of course quite likely that there are data anomalies in the numbers that IMD has collected from the north-east region, as automated weather stations that actually work are likely to be fewer in number than in ‘mainland’ India. (There is a spreadsheet for this data. If you want the data till date please write to me here: makanaka at pobox dot com.)

The first three weeks of monsoon 2012 in district averages for Nagaland, Manipur, Mizoram and Meghalaya

In the update, there is also a separate set of forecasts and probabilities for four major regions of India – North-West India, Central India, South Peninsula and North-East India. There are small variations for each of these in the definitions of below normal, normal and above normal. Here are the forecast probabilities for the regions:

The list of states in each of these four geographical regions is:
Northwest India: Jammu and Kashmir, Himachal Pradesh, Punjab, Rajasthan, Haryana, Chandigarh, Delhi, Uttaranchal and Uttar Pradesh.
Northeast India: Arunachal Pradesh, Meghalaya, Assam, Nagaland, Manipur, Mizoram, Tripura, Sikkim, West Bengal, Bihar and Jharkhand.
Central India: Gujarat, Madhya Pradesh, Chattisgarh, Maharashtra, Goa and Orissa.
South Peninsula: Andhra Pradesh, Karnataka, Tamil Nadu, Kerala, Lakshadweep and Andaman and Nicobar Islands.

Alarming reds and yellows over southern, central and northern India, threatening blues in north-eastern India (Bangladesh has been hit hard by floods). Graphic: IMD

The first stage forecast for the nation-wide season rainfall was issued on 2012 April 26 and this update was issued on 2012 June 22. The summary of the first stage forecast is:

“Southwest monsoon seasonal rainfall for the country as a whole is most likely to be Normal (96-104% of Long Period Average (LPA)) with the probability of 47%. The probability (24%) of season rainfall to be below normal (90-96% of LPA) is also higher than its climatological value. However, the probability of season rainfall to be deficient (below 90% of LPA) or excess (above 110% of LPA) is relatively low (less than 10%). Quantitatively, monsoon season rainfall is likely to be 99% of the LPA with a model error of ± 5%. The LPA of the season rainfall over the country as a whole for the period 1951-2000 is 89 cm.”

The IMD has said that it has taken into account the experimental forecasts prepared by the national institutes like Space Applications Centre, Ahmedabad, Centre for Mathematical Modeling and Computer Simulation, Bangalore, Center for Development of Advanced Computing, Pune and Indian Institute of Tropical Meteorology, Pune. Operational/experimental forecasts prepared by international institutes like the National Centers for Environmental Prediction, USA, International Research Institute for Climate and Society, USA, Meteorological Office, UK, Meteo France, the European Center for Medium Range Weather Forecasts, UK, Japan Meteorological Agency, Japan Agency for Marine-Earth Science and Technology, Asian-Pacific Economic Cooperation (APEC) Climate Centre, Korea and World Meteorological Organization’s Lead Centre for Long Range Forecasting – Multi-Model Ensemble have also been taken into account.

India lowers its 2011 monsoon forecast

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India’s meteorological department has issued its second long range forecast for the 2011 monsoon and has lowered its estimate. Rainfall will be 95% of the 50-year average in the June-September season, which are the monsoon months. In April, the Indian Meteorological Department predicted a monsoon that would be 98% of the long-term average. Normal precipitation is considered to be 96%-104% percent of the long-term average.

India’s agriculture-dependent population has been hoping for adequate rainfall to harvest good quantities of foodgrain and lentils for a second year and bring down inflation, which has led the Reserve Bank of India – the central bank – to raise rates for a 10th time in 15 months. Agriculture accounts for 14% of the economy and a reduced harvest can further lower rural incomes and send food inflation higher than it already is. Inflation in India is the highest among Asia’s major economies.

Bloomberg reported that the wholesale price index in India accelerated 9.06% in May after having increased 8.66% a month earlier, according to official data released on June 14. An index measuring wholesale prices of farm products including milk and lentils rose 8.96% in the week ended June 4 from a year earlier, according to the commerce ministry. India imported record quantities of sugar, lentils and oilseeds in 2009 following the weakest monsoon that year since 1972.

The IMD’s ‘long period’ is 1951-2000 and the department considers probabilities for the country (all-India) and four major regions: north-west India, central India, north-east India and south peninsula. “Over the four broad geographical regions of the country, rainfall for the 2011 Southwest Monsoon Season is likely to be 97% of its LPA over North-West India, 95% of its LPA over North-East India, 95% of its LPA over Central India and 94% of its LPA over South Peninsula, all with a model error of ± 8 %.”

The IMD also employs a six-parameter statistical forecasting system to prepare probability forecasts for five pre-defined rainfall categories. These are deficient (less than 90% of LPA), below normal (90-96% of LPA), normal (96-104% of LPA), above normal (104-110% of LPA) and excess (above 110% of LPA). The forecasted probabilities for the 2011 southwest monsoon season based on this system in percentage for the above 5 categories are 19%, 37%, 37%, 6% and 1%

The department’s ‘Summary of the Update Forecasts for 2011 Southwest Monsoon Rainfall’ has said:

(1) Rainfall over the country as a whole for the 2011 southwest monsoon season (June to September) is most likely to be below normal (90-96% of LPA). Quantitatively, monsoon season rainfall for the country as a whole is likely to be 95% of the long period average with a model error of ±4%. The Long period average rainfall over the country as a whole for the period 1951-2000 is 89 cm.

(2) Rainfall over the country as a whole in the month of July 2011 is likely to be 93% of its LPA and that in the month of August is likely to be 94% of LPA both with a model error of ± 9 %.

(3) Over the four broad geographical regions of the country, rainfall for the 2011 Southwest Monsoon Season is likely to be 97% of its LPA over North-West India, 95% of its LPA over North-East India, 95% of its LPA over Central India and 94% of its LPA over South Peninsula, all with a model error of ± 8 %.

According to Reuters, government officials played down concerns that lower rainfall could fan inflation and dampen growth. “There is no need to press the panic button, as June rains are still above normal,” said Shailesh Nayak, the top civil servant in the ministry of earth sciences which controls the country’s weather office.

While rains could be slightly lower than normal in July, India’s chief forecaster said distribution was key. “There are chances the monsoon will pick up after July 15 once it covers the entire country,” said D. Sivananda Pai, director at the state-run National Climate Center. “Don’t go by the numbers, it is the distribution (of the rains) which we are still hoping to be good.” The weather office predicted 27 centimetres of rain in July compared with long-term average rainfall of 29 centimetres, and rains at 24 centimetres in August, when seeds start maturing, compared with long-term averages of 26 centimetres.

Weather office chief Ajit Tyagi remained optimistic. “Ninety five percent is a good forecast,” Tyagi said. “Had it been 90% of the long-term average then it would have been a cause for concern,” he said, adding that in the past slightly below normal monsoon rains had also seen adequate farm output because they were well distributed in the major crop growing regions.

Explaining climatic conditions over the equatorial Pacific and Indian Oceans, the department’s second long range said moderate to strong La Nina conditions that prevailed in the equatorial Pacific during mid-August 2010 to early February 2011 weakened during subsequent months and dissipated to neutral conditions around mid-May 2011. The latest forecasts from a majority of the dynamical and statistical models indicate strong probability for the present ENSO-neutral conditions to continue during the current monsoon season and the remaining part of 2011.

It is important to note that in addition to El Niño and La Niña events, other factors such as the Indian Ocean Sea surface temperatures (SSTs) have also significant influence on India monsoon. However, the latest forecasts do not suggest development of either a positive or a negative Indian Ocean Dipole event during the 2011 monsoon season. In the absence of strong monsoon forcing from both Pacific and Indian Oceans, intraseasonal variation may become more crucial during this southwest monsoon season and lead to increased uncertainty in the monsoon forecasts.