Southwest monsoon reaches Kerala

FROM BLOG EDITION - http://www.downtoearth.org.in/content/southwest-monsoon-reaches-kerala

As of now, conditions are favourable for its progress

Progress of southwest monsoon over India (Courtesy: IMD)
 

After a delay of four days, the southwest monsoon finally arrived in Kerala on Friday, June 5. According to a press release by India Meteorological Department (IMD), the southwest monsoon has advanced over the entire south Arabian Sea, some parts of central Arabian Sea, Lakshadweep, Kerala, parts of coastal and south interior Karnataka, Tamil Nadu and some parts of Bay of Bengal.

As of Friday afternoon, the Northern Limit of Monsoon (NLM) or its northern boundary was passing through Mangaluru (Mangalore) and Mysuru (Mysore) in Karnataka and Salem and Cuddalore in Tamil Nadu. The onset of monsoon was delayed in Kerala and southern India by five days even last year. 

This year, the monsoon reached the Andaman and Nicobar Islands region on time, but lost its momentum and lingered around Sri Lanka for more than a week. Thus, it missed both its normal onset date and the date forecast by IMD (May 30). 

It is also running late in the North East and eastern India as the Bay of Bengal branch of the monsoon hasn't made any significant progress when compared to the Arabian Sea branch. 

Despite this delay, India is seeing a "good opening" of the summer monsoon season. From June 1 to 5, rainfall in India was 4 per cent more than normal, thanks to a combination of a western disturbance in the north, pre-monsoon showers in the south, monsoon showers in the Andaman and Nicobar Islands and multiple localised thunderstorms in other parts of India. 

The monsoon has another 118 days (till September 30) to perform in India. Factors such as the state of El Niño Southern Oscillation, Indian Ocean Dipole and frequency of monsoon depressions will influence its performance. 

Arabian Sea low pressure to boost monsoon's progress

Monsoon could regain its lost momentum because of a low pressure system in the Arabian Sea. For the onset of the monsoon in Kerala, it's important for a few atmospheric parameters such as rainfall and wind to achieve threshold values. This low pressure helped build clouds near Kerala which brought widespread rains to the region. Plus, its presence influenced the wind speed and direction and made them favourable. In this way, the low pressure helped pull the monsoon that was stuck over Sri Lanka to southern India. As of the afternoon of June 5, this low pressure system was situated off the west coast of Kerala-Karnataka and had lowest mean sea level pressure of 1004mb. 

Initially, multiple weather models showed that this system would intensify into a tropical cyclone and move parallel to the western coast of India. This could have led to a June 2014-like situation of monsoon's bizarre progress due to Cyclone Nanauk. But as per the present weather model runs, this system would marginally intensify and head almost northwards in a curved path. As of now, the probability of formation of a cyclone like Nanauk is very low. This system would dissipate in the northern Arabian Sea by June 11 and, hence, there is no threat to India. 

To some extent, monsoon is expected to progress faster along the west coast as compared to the interior areas of southern India till June 10. In this period, the western coast (including Mumbai, Pune) will witness rainfall with windy weather due to this system. The Arabian Sea will see rough conditions due to the low pressure. It is expected that the monsoon will arrive in more parts of Karnataka, remaining parts of Tamil Nadu and, possibly, southern parts of Andhra Pradesh by June 8. Mostly dry and hot weather will be witnessed in northern India during this period. 

IMD forecasts deficient monsoon

IMD downgraded the monsoon forecast, from 93 per cent to 88 per cent, dashing hopes of relief from drought in many parts of India. Thus, the forecast is now of deficient rainfall instead of below normal rainfall. (Note that the error range for these estimates is +/- 4 per cent.)

IMD also gave a region-wise forecast in this update. It said that northwest India will receive 85 per cent of LPA (LPA stands for Long Period Average or the average rainfall recorded from 1951 to 2000). Central India will receive 90 per cent of LPA, south peninsula will receive 92 per cent of LPA and northeast India will receive 90 per cent of LPA. All these figures are subject to an error of +/- 8 per cent. 

A decrease of 5 per cent in the rainfall forecast is significant. Monsoon rainfall in India exhibits a large spatial variation and, hence, this 5 per cent decrease can bring a significant decrease in rainfall at many places in India. For example, in 2014, IMD had forecast a rainfall of 94 per cent of LPA for central India. The observed rainfall was 90 per cent of LPA, but the monsoon rainfall in places like Marathwada in Maharashtra was 42 per cent below normal. 

Likewise, rainfall in north-west India was forecast at 85 per cent of LPA. The observed rainfall was 79 per cent of LPA, but a strong rainfall deficiency was seen in the region. Haryana-Chandigarh-Delhi and western Uttar Pradesh recorded 56 per cent below normal rainfall. This is why IMD's downgraded forecast 

Monsoon reaches Andaman & Nicobar Islands

FROM THE BLOG EDITION: http://www.downtoearth.org.in/content/monsoon-reaches-andaman-nicobar-islands

But with experts predicting 90 per cent chance of El Niño, uncertainty looms over monsoon's overall performance

Map showing the advance of south-west monsoon 2015. (Courtesy- India Meteorological Department)

India's much-awaited annual visitor, the south-west monsoon, has arrived at its first destination—Andaman and Nicobar Islands. On Saturday, May 16, the India Meteorological Department (IMD) announced that the monsoon advanced over south Andaman Sea, Nicobar Islands, some parts of south-east Bay of Bengal, north Andaman Sea and Andaman Islands (see image above). As per IMD, as of May 18 afternoon, the northern limit of monsoon continues to pass through 05.0°N/ 86.0°E, 10°N/90.0°E, Long Islands and 15.0°N/98.0°E. Usually, the monsoon reaches south Andaman Sea by May 15, and hence, as expected, it has arrived on time in Andaman and Nicobar Islands region.

For declaring the monsoon onset in Andaman Sea and Andaman and Nicobar Islands, IMD considers some basic conditions such as rainfall in these areas and direction of near surface winds. A nice flow of the near surface winds has been established between the southern Indian Ocean and northern Indian Ocean (particularly, Bay of Bengal). My previous blog explained how the monsoon winds originate in the southern hemisphere, cross the equator and then move towards India. Such a textbook flow is called cross-equatorial flow which is well established now and will be strengthening in the coming days. This will enable the monsoon to cover more parts of the Bay of Bengal region in the coming three to four days.

Weak onset predicted for Kerala

On May 14, IMD issued a press release  on monsoon's onset in Kerala. The Met officials are expecting the monsoon's arrival in Kerala on May 30 (onset window between May 26 and June 4). For declaring the monsoon's onset in Kerala, IMD has well-defined criteria. As per the present situation, the wind field parameter isn't in the acceptable range till May 30. But, the long range weather models indicate improvement in the situation from around June 1. Hence, if IMD decides to strictly follow the onset parameters, onset in Kerala would be declared by June 4. However, a weak onset phase is anticipated in Kerala and nearby areas.

El Niño intensity

Weak to moderate El Niño conditions are well established now in the equatorial Pacific Ocean as per Climate Prediction Centre (CPC) of USA's National Centers for Environmental Prediction (NCEP). As per Bureau of Meteorology of Australia, early stages of El Niño are appearing. Unlike last year, the Pacific Ocean and atmosphere above it are "in sync" now. Both Australian agency and CPC-NCEP agree on this. 
The sea surface of equatorial Pacific Ocean has been warmer than normal (positive sea surface temperature anomaly), mostly since last year. But the present temperature anomalies are greater than that of previous year.
  
On Thursday, May 14, CPC and International Research Institute for Climate and Society issued their monthly diagnostic discussion on El Niño Southern Oscillation (ENSO). According to this discussion, there is an approximately 90 per cent chance that El Niño will continue through the summer 2015 in Northern Hemisphere. Also, there is a greater than 80 per cent chance that El Niño will last through the entire 2015.

The image below shows various projections of the sea surface temperature (SST) anomalies in the Niño 3.4 region in the coming months. Niño 3.4 region lies between 120°W-170°W, 5°N-5°S and sea surface temperature anomalies for this region are mainly considered in ENSO forecasts. On the vertical axis, SST anomalies in degree celsius for this El Niño 3.4 region are represented and on the horizontal axis, groups of three months (for example, MJJ stands for May-June-July). Various curves indicate projections of various models (listed on the right side in the image), which are of two types—dynamical and statistical. Dynamical models are based on the usage of present weather conditions for forecasting. Statistical models give projections by applying statistics to past observations. Hence, dynamical models perform better than statistical models for ENSO forecasting.

As per the image, most of the models (both dynamical and statistical) are in agreement of warmer than normal SST in the Niño 3.4 region. Most of the curves tend to increase in the coming period, which means a possibility of strengthening of El Niño conditions. The average of dynamical models (shown as thick yellow coloured curve) shows that the SST anomalies in Niño 3.4 region would be between 1°C to 1.5°C in the coming period. That's why such a high percentage of possibility of El Niño conditions has been forecast for the coming months.

Plume of ENSO forecasts. (Courtesy- IRI/ CPC)

But there is catch, and it's due to the ongoing spring season. At this time of the year, seasonal transitions take place (like summer to monsoon for India). Likewise, a transition in the phases of ENSO also takes place in the Pacific Ocean. The phases like El Niño/ La Niña peak during Northern Hemisphere's winter season. During next year's spring season they are in transition. Suppose that we had an El Niño/ La Niña which peaked in the previous year's winter, then at present El Niño/ La Niña conditions would be weakening in the Pacific Ocean. Even an El Niño might be under the development in this period and hence there is a huge uncertainty in what the models expect about the status of ENSO in the coming months. Technically, this spring period in which models have a tough time in making forecasts is referred to as "spring predictability barrier". The discussion of CPC which has given a high percentage for El Niño conditions also mentions "there remains considerable uncertainty about how strong the El Niño event may become". 

Depth of warm water (shaded yellow/orange/red) in the equatorial pacific ocean as on 13th May 2015. (Courtesy- CPC)

India's summer monsoon season will be officially commencing from June 1, 2015.The Indian Ocean Dipole is anticipated to remain in the neutral stage as per Bureau of Meteorology, Australian, and this definitely wouldn't be a good news for the monsoon. Also, it is certain that El Niño or El Niño like conditions will be present at least till the half of the monsoon season.

The above image shows the location and depth of warm water in the equatorial Pacific Ocean. Yellow/orange/red shades indicate warmer water and the depth scale is given on the vertical axis. It is clear that a large pool of warm water has spread till a depth of about 250-300m in the central Pacific Ocean. It is even deeper in the eastern equatorial Pacific Ocean (east of 100°W). So, even if we assume that in the coming months no fresh heating of the surface water takes place through direct ways, this pool of warm sub-surface water will in itself be sufficient to keep the surface water of Pacific Ocean warm in the months to come. This would keep the atmospheric circulation affected and hence the monsoon also would remain affected.

In a nutshell, as per the present scenario, a weaker than normal monsoon is expected in at least first half of the monsoon season. Rainfall situation wouldn't be good in areas of Maharashtra like Marathwada.

Akshay Deoras is an independent weather forecaster

Countdown to monsoon arrival starts

4

BLOG EDITION : http://www.downtoearth.org.in/content/countdown-monsoon-s-arrival-starts

Will the southwest monsoon arrive on time over the Andaman and Nicobar Islands?

Normal dates for onset of southwest monsoon over India (Photo courtesy: India Meteorological Department)

As May begins, the countdown to the onset of the southwest monsoon in India has started. As per the standard timetable, it is normally expected to reach the Andaman and Nicobar Islands region about two weeks from now. Usually, by May 15, monsoon reaches the south Andaman Sea. By May 20, it covers almost the entire Andaman and Nicobar Islands. By May 25, it covers most of Sri Lanka, some parts of Myanmar and by June 1, it arrives in Kerala, most of Tamil Nadu and southeast Andhra Pradesh. 

However, it's not that easy for the monsoon to follow a strict timetable, just like we find it hard to do so in our daily lives. There are many factors which determine not only monsoon's performance, but also its timetable in a given year. The monsoon onset dates (shown in the image above) have been calculated by India Meteorological Department (IMD) based on rainfall recorded decades ago.

People often say that when they were children, monsoon used to arrive over the mainland of India on time, but they have been seeing variability in the onset of monsoon over the last few years. As a result of the natural variability in the monsoon system, these onset dates rarely hold true now (the southwest monsoon used to reach central India around June 10 earlier, but it doesn't anymore). Hence, there is a strong need to follow new monsoon onset dates or a new timetable. Weather factors are also responsible for the variations in the onset date. 

Monsoon arrived late over the Andaman and Nicobar Islands in 2005, 2011, 2012. But it also arrived before time in this region in 2007, 2008 and 2010. Let us assume the southwest monsoon is like a train going from the Andaman and Nicobar Islands towards Pakistan, stopping at several stations on the way. We have seen how a train reaches its final destination on time even if it has turned up late at the intervening stations by making up for lost time. The same thing happened in 2012 when the monsoon was "running" late near the Andaman and Nicobar Islands, but it reached Pakistan on July 11, before the normal date of July 15. 

But sometimes, the monsoon tends to stall at some places on its way across the Indian subcontinent. An on time or early arrival at the Andaman and Nicobar Islands doesn't guarantee a timely arrival in the rest of the country. 

It has been observed that low pressure systems (such as cyclones) in the Arabian Sea and the Bay of Bengal during May and June can interfere with the onset of the monsoon. The position, intensity and timing of such low pressure systems determine whether their presence would help the monsoon or not. Monsoon's bizarre progress in 2014 due to Cyclone Nanauk is a classic example. It helped the monsoon progress along the west coast of India, but couldn't help its progress in the interiors. 

There are so many possibilities every year that the accuracy of a long-term forecast of monsoon onset dates is always low. 

The monsoon journey in 2015 

In my previous blog, I had explained how some basic parameters play a vital role in the monsoon's performance. 

The first thing to look at will be the status of Mascarene High or the "powerhouse of monsoon". The above image of April 30, 2015 of the higher latitudes in the southern hemisphere shows "H 1028" written in a red circle. H 1028 means a high pressure region having mean sea level pressure of 1028 millibar (we consider 1013 millibar as standard mean sea level pressure) and theoretically, this is the position of Mascarene High. It must also be borne in mind that no two monsoon setups can be exactly similar and hence, some variation occurs. However, this year's setup is fairly impressive if one compares it with that of last year when the monsoon had reached Andaman and Nicobar on time. 

Last year, on the evening of May 1, a strong high pressure region was powering the winds in the southern hemisphere. This high pressure region can be seen here as a whitish patch off the southwest coast of Australia. Its highest mean sea level pressure was 1036 millibar. The star-trail like features from the west coast of Australia are monsoon winds which need to be fast enough to reach the equator and, then, come towards India. This high pressure region shifted westward and on May 5, 2014, it was located southeast of Madagascar as can be seen here. 

If we look at the situation on the evening of May 1, 2015, the star-trails (the winds) seem to be moving much slower as compared to last year. 

The good news as of now is that long range weather models show the possibility of an improvement in this setup in the coming days. They also show an increase in the rainfall activity in the Andaman and Nicobar Islands towards May 15 with better organisation of surface winds. But such long range weather models fluctuate a lot and, hence, blindly believing them will not be a good idea. 

As of now, the probability of an on-time arrival of the monsoon over the Andaman and Nicobar Islands is higher. In the coming days, we can expect to get a better picture of the expected status of El Niño and the Indian Ocean Dipole during the monsoon period and a close monitoring of conditions will help us have a better idea about this year's monsoon. 

Akshay Deoras is an independent weather forecaster

The Great Indian Monsoon System

BLOG EDITION : http://www.downtoearth.org.in/content/great-indian-monsoon-and-its-friends

A look at the association between the southwest monsoon and its companions

Henry Ford, the founder of Ford Motor Company, once said, "My best friend is the one who brings out the best in me."

This fact is observed not only in our daily lives, but also in the case of the Indian summer monsoon's (also called southwest monsoon) performance every year.
The southwest monsoon is so powerful that its performance from June to September decides the state of agricultural productivity in India, which in turn, decides the state of the economy. Thus, it is no less important than the finance minister himself.

The monsoon affects a region comprising nearly 25 countries and its influence stretches across a distance of 18,000 kilometres (from east to west) and 6,000 kilometres (from south to north).

Just like the performance of the monsoon is often compared to a game of cricket, one can also compare it to friends (here it means various atmospheric and oceanic conditions).

We gauge only the performance of the monsoon, but in reality, its friends are also working round-the-clock in the background to bring out its best performance. 
However, the twist in the story is that some of monsoon's friends are prone to changes. They can even become its enemies in a particular year and bat on behalf of the opponent team.

It is this mutability which causes variations in monsoon's performance and hence, no two monsoons are similar in nature.

Five special conditions
The Earth System Science Organisation (ESSO) and the India Meteorological Department (IMD) take into account five conditions while making forecasts about the monsoon in April every year.

These special conditions are as follows:

1) The Sea Surface Temperature (SST) gradient between the north Atlantic and the north Pacific (conditions during December of the previous year and January of present year)
2) SST of the equatorial south Indian Ocean (conditions during February and March of the present year)
3) Mean Sea Level pressure in east Asia (conditions during February and March of the present year)
4) The surface air temperature over northwest Europe (conditions during January of the present year)
5) The warm water volume of the equatorial Pacific Ocean (conditions during February and March of the present year)

Here are some friends of the Indian monsoon which are responsible for its existence and good performance over the years.

Mascarene High: monsoon's best buddy
The figure shows how Mascarene High works as the powerhouse of monsoon winds. Shades as per the scale represent the mean sea level pressure and the arrows indicate the direction of surface winds (Credit: Penn State Meteorology Department, ESRL, Philip Lutzak page)
The southwest monsoon derives its name from winds which blow from a south-westerly direction in the Indian subcontinent. We often read about "southwest winds" in various news reports or weather forecasts. But rarely do we think about the "source" of these winds. These come from a powerhouse located more than 4,000 kilometres from India. This powerhouse is known as the Mascarene High. This high-pressure region is located between 25°S-35°S and 40°E-90°E near theMascarene Islands in the southern Indian Ocean. 

Normally, this high-pressure region starts forming by mid-April and its strength is an important factor which determines the intensity of monsoon in India.

A stronger high pressure will produce stronger winds or monsoon current. If there is a delay in the formation of Mascarene High, there is also the possibility of a delay in the onset of monsoon in India. Mascarene High has been a subject of research for many years. Most research says that its strength is determined by the happenings in the Antarctic region.

But overall, this factor is not often held responsible for delays and poor performance of the monsoon in India. As a result of its punctuality, Mascarene High is considered its best buddy.

Coriolis Force: monsoon's trusted lieutenant
Winds from Mascarene High head in a north-westerly direction towards the east coast of Africa (Somalia). (See image 1)

Here, the topography of Somalia deflects the winds towards the east. Also, after crossing the equator, these winds experience the Coriolis Effect.

Coriolis Force is a pseudo force which exists only because of the Earth's rotational effect. Rotational motion observed in a tropical cyclone is also due to this force. Hence, these monsoon winds get deflected eastwards and now they blow from south-west to the north-east direction. They split into two branches—the Arabian Sea branch and the Bay of Bengal branch.

See the motion of these monsoon winds on June 21, 2014, here. 
In this graphic, the green-coloured moving star trail-like features are the winds at the surface level. Notice how they come from the southern hemisphere and then get deflected eastwards in the northern hemisphere. As the Earth's rotational velocity is constant, the Coriolis Force experienced at a given latitude by a given parcel of air having a definite velocity is also constant.

That is why the Coriolis Force is monsoon's trusted friend.

Indian summer: monsoon's guide 
The figure shows the mean sea level pressure during July 2014. The purple colour shows regions of low pressure whereas the yellow-shaded regions over the Indian Ocean show areas of higher pressure (Credit: earth.nullschool.net)
A mechanism is needed to attract the monsoon winds from the Arabian Sea or the Bay of Bengal. We keep reading about tropical cyclones or troughs or low pressure regions which are great attractors of winds in the Earth's weather system.

Winds flow from high pressure to low pressure areas. We all are familiar with India's summer season or pre-monsoon season as defined by the IMD. The Himalayan range plays a vital role in summer heating by restricting the intrusion of cold air from the north and allowing heating to occur. It is during this season that the land of India, particularly Rajasthan and surrounding areas (Gujarat and also Pakistan) heat up extensively. The seas surrounding the country also see a temperature rise. As a result of the differential heating rates and capacities of air over the sea and the land, we observe a gradient between air pressure over the sea and that over India (especially Rajasthan). The air pressure over India is lower than that over the southern part of the Arabian Sea and the Bay of Bengal. This acts as an attractor mechanism for the monsoon winds.

Thus, the summer season of India acts as the monsoon's guide.

El Nino Southern Oscillation: the undependable friend

El Nino Southern Oscillation (ENSO) refers to the oscillatory mode of the sea surface temperatures near the equatorial Pacific Ocean in which a warming (El Nino or cooling (La Nina) or neutrality is observed. Due to its mostly unpredictable nature, ENSO has been a big challenge for forecasters since a long time. Even trusted models have failed many a time.

Take the case of last year. Right from February-March, there were many instances during which the models indicated a moderate to high probability of El Nino formation, but it did not turn up till almost the end of 2014.

This was because the atmosphere and the ocean could not synchronise in most of the cases.

But things started getting organised better as 2015 kicked off and El Nino conditions started appearing in the western and central equatorial Pacific Ocean since February.

As a result of this, the Climate Prediction Center/NCEP/NWS and the International Research Institute for Climate and Society issued an El Nino advisory in March 2015.

Their April discussion suggests that "there is an approximately 70 per cent chance that El Nino will continue through Northern Hemisphere summer 2015 and a greater than 60 per cent chance it will last through autumn".

ENSO has been a driver of global weather (particularly in countries surrounding the Pacific Ocean) as it affects atmospheric circulation.

The El Nino concept became more popular in the Indian media after the drought of 2009. At the time, India received 21.8 per cent less than normal rainfall (Long Period Average of 89 cm). In fact, the major droughts of 1982 (-14.5 per cent rainfall), 1987 (-19.4 per cent rainfall), 2002 (-19.2 per cent rainfall), 2004 (-13.8 per cent rainfall) and 2009 (-21.8 per cent rainfall) were accompanied by a full-blown El Nino. However, there have been many El Nino years during which India received near normal or above-normal rainfall such as 1983 (13 per cent), 1994 (12.5 per cent), 1997 (2.2 per cent) and 2006 (-0.4 per cent).

Thus, ENSO is monsoon's undependable friend.

Indian Ocean Dipole: monsoon's latest friend
The image shows phases of the Indian Ocean Dipole and its impact on India's weather (Credit: WHOI/NCU (Obtained from Introduction to Tropical Meteorology, 2nd edition)

In 1999, N H Saji of Japan's University of Aizu and others discovered an ENSO-like phenomenon in the Indian Ocean which they named the Indian Ocean Dipole (IOD).

Like ENSO, IOD also has three phases—positive, negative and neutral. During the positive phase of IOD, sea surface temperatures are warmer in the western Indian Ocean (which gives a boost to monsoon winds) as compared to the eastern Indian Ocean—hence a dipole nature.

The reverse happens during IOD negative and no gradient is observed during the IOD neutral period.

It has been observed that during the period of positive IOD, the Indian summer monsoon rainfall is considerably good as compared to the negative IOD period. Despite 1994 and 2006 being El Nino years, India did not witness a drought as IOD was significantly positive. Thus, in some ways a strong positive phase of IOD tries to counter the negative effects of El Nino. But the relation between IOD and monsoon rainfall is still being debated and has not been fully comprehended.

Compared to the roles of Mascarene High, Coriolis Force, India's summer season and ENSO, IOD's role has been discovered recently.
It will be interesting to see how these parameters evolve in the ongoing pre-monsoon period. 
 

Akshay Deoras is an independent weather forecaster

Double trouble heading for Jammu and Kashmir

BLOG EDITION- http://www.downtoearth.org.in/content/double-trouble-heading-jammu-and-kashmir

*** THIS IS A PARTICULARLY DANGEROUS SITUATION *** 

*** Considering the approaching rainfall event, we advise the people to suspend their travel to ‪#‎Srinagar‬, ‪#‎Kashmir‬ till April 6th *** 

*** This is a brief pause of rains. People should not get misguided by it and ignore warnings as similar weather conditions will start from Wednesday, 1st April 2015*** 

After a brief pause, heavy rains will resume on Wednesday

March started with a bang. It will also end with a bang. More rains are on the way for Jammu and Kashmir. The anticipated western disturbance and upper air trough have produced heavy rainfall in the state, particularly in the Kashmir valley and in and around Jammu.

In the past 24 hours (till 8:30 am IST on March 30), Katra had received heavy rainfall, measuring 139 mm. It was followed by 124 mm at Batote in Ramban district, 98.1 mm in Jammu, 72 mm in Banihal, 70 mm in Qazigund, 58 mm (precipitation) in Pahalgam, 50.6 mm in Srinagar, 40.1 mm in Gulmarg and 65.8 mm in Bhaderwah in Doda district . While the absolute amounts seem too low to trigger floods, the topography of the state makes it more vulnerable to flooding.Urbanisation has led to the collapse of natural drainage systems in Srinagar, causing an increase in water logging.

Reports of floods are emerging from Srinagar and other areas. Many areas in Jammu have been waterlogged due to rains. Mudslides have been reported from areas like Budgam and the state government has declared a flood. Two teams of 100 personnel of the National Disaster Response Force have been sent to Srinagar and hundreds of people have already been evacuated. Landslides have also been reported on the Jammu-Srinagar highway. It has remained shut today for the third day in a row. To make the things worse, Jhelum river has started swelling due to heavy rains. On Monday morning, it had crossed the danger level in Srinagar and Sangam areas of south Kashmir, as per reports. Schools have been closed for two days and board and university exams have been postponed. 

The effect of western disturbance is, however, receding. At the time of writing this post, Srinagar and Jammu were reporting a partly cloudy weather. As per the GFS weather model, the weather in the state will continue to remain a little cloudy on Monday and Tuesday. Light rains or drizzle can be expected in the state. This brief pause in rainfall will help in the receding of water from places like Srinagar.  Even the water level of Jhelum will decrease a little due to the absence of rains.

But come Wednesday and rains will once again commence in the currently affected areas. Rainfall will continue in periods till April 6. According to current estimates, western Jammu and Kashmir will witness heavy rains on Wednesday and Friday. Rains will decrease from April 4. 

This will likely bring back water logging and cause an upsurge in the water level of the Jhelum. As the river is already seeing an upsurge, even a little rainfall is likely to make the river exceed the danger level again. The authorities claim that, after last year’s flood, they strengthened the embankments and no breaches have been reported so far.

There will also be heavy snowfall in the higher reaches, causing landslides and avalanches in prone areas. This will keep the Jammu-Srinagar highway closed during the period from April 1 to 6. Srinagar airport may also see disruptions during this period due to water logging.

People living in these areas must stay alert. Following are the precautions people must follow: 

• Keep with you water (at least a 5-day supply), food (at least a 5-day supply of non-perishable, easy-to-prepare food), flashlight, battery-powered radio, extra batteries, first aid kit, medications (7-day supply), cell phone with chargers, family and emergency contact information, extra cash, emergency blanket, tools/supplies for securing your home, extra clothing, hat and sturdy shoes and rain gear.
• Listen to area radio and television stations for authentic details. 
• Be prepared to evacuate at a moment’s notice. Stay away from landslide- and avalanche-prone zones. 
• When a flood or flash flood warning is issued for your area, head for higher ground and stay there.
• Stay away from floodwaters and the river Jhelum. If you come upon a flowing stream where water is above your ankles, stop, turn around and go another way. Six inches of swiftly moving water can sweep you off of your feet.
• If you come upon a flooded road while driving, turn around and go another way. If you are caught on a flooded road and waters are rising rapidly around you, get out of the car quickly and move to higher ground. Most cars can be swept away by less than two feet of moving water.
• Keep children out of the water. They are curious and often lack judgment about running water or contaminated water.
• Be especially cautious at night when it is harder to recognise flood danger.

Akshay Deoras is an independent weather forecaster

Disturbance from West ceases, mercury set to rise

BLOG EDITION- http://www.downtoearth.org.in/content/disturbance-west-ceases-mercury-set-rise

Relief in sight for states in the grip of swine flu

State-wise rainfall in India between March 1 and March 11, 2015 (courtesy IMD)

Latest data of the India Meteorological Department (IMD) confirms what most Indians already know from experience. The data shows rainfall received between March 1 and 13 in most areas (coloured blue in the India map) has been in excess of 20 per cent or more. In this period, India normally receives about 9.8mm rain but this time it has received 33.2 mm rain.

The figures in the map may not appear alarming but it’s important to note that these are the weighted average values (weighted mean). In this method of averaging, proper numerical weights (numbers) are assigned to every observation and then their weighted mean is calculated. Rainfall measurement is done in a similar manner as explained by the National Oceanic and Atmospheric Administration (NOAA) of the US. As per this technique, India reported a strong 239 per cent departure (from normal) in rainfall in this period. The weather eventwhich lasted between February 28 and March 3 has been the major contributor in this rainfall amount.

Swine flu’s link to weather events 
These back to back rainfall events not only damaged the crops but also kept a lid on the maximum temperatures at many places. Such a condition is usually favourable for the swine flu virus which has been causing a havoc in India. Maximum impact of swine flu is being reported from Rajasthan, Madhya Pradesh, Telangana, Uttar Pradesh, Maharashtra, Delhi and Gujarat. State-wise per cent rainfall departures (March 1 to March 11) in these states are astonishing. The per cent rainfall departures (from normal) in Gujarat is 42,811;  2,757 for Rajasthan; 932 for Madhya Pradesh; 1,240 for Delhi; 720 for Telangana; 1,554 for Maharashtra and 750 for Uttar Pradesh. The rainfall amounts will be even more when the data from past week weather outbreak is considered.

District rainfall departure map for north-west India for the period March1-March 11 (courtesy IMD)

After these havoc-causing events in the initial two weeks, weather in India has started to stabilise. Going by the projection of weather models like Global Forecast System (GFS), it looks like some significant heating is possible over the next couple of days. This is likely to kick off the summer season in India. The meteorological seasons in India, as defined by IMD, are pretty strange. According to its definition, India has a winter season which lasts between January and February but it doesn’t have a summer season. Most of India (except for parts of southern India) witnesses winter conditions mostly from November. IMD defines the October- December period as a post monsoon period. It calls the period of March to May (when India sweats due to significant heating) as the pre-monsoon season.

As per GFS, no western disturbance is expected in India for (at least) one week. Plus, the upper air is also expected to remain stable as no trough is expected over India in the next few days. Hence, the weather is likely going to stay clear at most of the places which would be an important factor in increasing the heat and hence the temperatures--maximum and minimum. Even the swine flu-affected states are going to witness significant heating which would likely result in a drop in the number of swine flu cases.

Expected mean surface temperature in India over the next few days (courtesy: IGES/COLA)The above image gives an idea of the expected heating. Top map shows the expected mean surface temperature (in degree Celsius) between March 18 and 26, 2015. The scale is given to the left side. Bottom image shows the expected temperature anomaly (in degree Celsius). The long range forecast (March 26 to April 3) given in the middle image may not be that reliable right now but it is possible that the heating will continue in April first week also. Reddish regions in much of India indicate higher than normal temperatures. Below is what can be expected till March 26, 2015.

Initially, places in Rajasthan would be getting a maximum temperature around 35°C and it may rise even further in the next week. Maximum temperature in Jaipur is expected to remain near 32-33°C in this period. Gujarat is also going to get higher maximum temperatures in the coming days. Significant heating is possible due to which maximum temperatures will likely stay in the 35-40°C range. Maximum temperatures at places like Vidarbha in Maharashtra are likely to near 40°C. Other places like Marathwada will also witness maximum temperatures around 35°C in the coming period. Mumbai should be staying at around 35°C. Delhi, too, will start experiencing heating as maximum temperatures will touch 30°C initially and then will rise above 30°C in the coming period. Places in Madhya Pradesh and Uttar Pradesh will also be warm. Many places in Telangana are already reporting a maximum temperature of around 35°C. The weather is likely to be similar in the coming period.

Akshay Deoras is an independent weather forecaster

Severe western disturbance to hit North India

BLOG EDITION: (http://www.downtoearth.org.in/content/severe-western-disturbance-hit-north-india)

Heavy rains and snowfall predicted in Jammu and Kashmir and Himachal Pradesh

Western disturbances or the areas of "disturbed air pressure" travelling to India from the west are a regular feature through the winter season. These are basically "extra-tropical storms" or low pressure systems originating outside the tropical regions. The rain and snow they bring in their wake to north India and neighbouring regions is formed from the moisture they carry from the Atlantic Ocean or the Mediterranean Sea.

This winter season's most powerful western disturbance is all set to hit north India from this Wednesday (January 21). The countdown for its arrival has already started.

Expected impacts

Monday afternoon's infrared satellite image from India Meteorological Department shows the approach of the western disturbance.

Every western disturbance is different from the previous one due to the differences in intensity. Following is what can be expected from this system.

Tuesday, January 20: Clouds due to this western disturbance will start arriving (mostly from evening) in Jammu and Kashmir and western Punjab. No severe weather threat expected on this day.

Wednesday, January 21: Western disturbance will start impacting north India. Increasing cloud cover will be seen in Jammu and Kashmir, Himachal Pradesh and in the plains of north India. Rains or snow will start in Jammu and Kashmir, Himachal Pradesh; it will turn heavy from evening onwards.

Up to four feet (1.22 metre) of snow (snow depth) is expected to accumulate in eastern Kashmir valley (Pahalgam included) on this day. About 14 inch (36 cm) of snowfall is expected in northern Himachal Pradesh; remote areas likely to get cut off.

Rainfall is also expected in Punjab, Haryana, Chandigarh, southern Gujarat and eastern Rajasthan. Overnight rains possible in Delhi-NCR with reduction in fog from Wednesday due to increasing cloud cover.

Thursday, January 22: A wet and cool day for almost entire north India. Rains expected to cover more parts of north India plains. Heavy snowfall will continue in the higher reaches of Jammu and Kashmir and Himachal Pradesh on this day. Srinagar is likely to receive the first snowfall of the season in the early morning hours of Thursday. Freezing rain shall continue in the later hours of Thursday. Moderate snowfall for Ladakh forecast on this day.

Due to snow accumulations, Jammu-Srinagar highway may get closed on this day along with minor disruptions in the flight schedules at Srinagar and Leh. Disruptions expected in the rail traffic in Jammu and Kashmir.

Reduction in the rain/snow from late night hours, but it will give way to extreme cold weather in these areas.

Friday, January 23: Light snowfall can be expected in higher reaches of Jammu and Kashmir and Himachal Pradesh. Dense fog expected to return to the plains of Punjab, Haryana, Chandigarh, Delhi-NCR and Uttar Pradesh.

The weather will clear up after this.

Some tips on how people in Jammu and Kashmir and Himachal Pradesh can make themselves weather ready:

• Store sufficient heating fuel. Store a good supply of dry, seasoned wood for your fireplace or wood-burning stove.
• Keep adequate dry clothing and blankets, stock of medicines and food.
• Bring pets/companion animals inside during winter weather. Move other animals or livestock to sheltered areas with non-frozen drinking water.
• * Minimise travel and stay indoors in this period.
• * Follow the warnings issued by local government agencies.

Refer this link http://www.ready.gov/winter-weather for more tips regarding how to prepare from this western disturbance.

Akshay Deoras is an independent weather forecaster