Posts Tagged ‘Indian monsoon’

Indian monsoon should be on time as El Niño dissipates

May 18, 2016

The Indian monsoon is influenced by anomalies in the Niño 3.4 region.

nino regions

nino regions

“El Niño (La Niña) is a phenomenon in the equatorial Pacific Ocean characterized by a five consecutive 3-month running mean of sea surface temperature (SST) anomalies in the Niño 3.4 region that is above (below) the threshold of +0.5°C (-0.5°C).”

In the last 2 weeks the Niño 3.4 region has seen the SST anomaly drop from 1.1°C on April 25 to 0.6°C now. So it does look like that the current El Niño is dissipating and will very soon reach neutral conditions. That comes just in time for this year’s Indian monsoon (official season from 1st June to 30th September).

Both the government Indian Meteorological Department (IMD) and the private Skymet forecast an above average monsoon (about 10% above “normal”). However the IMD forecasts that the onset of the monsoon over the south-west coast will be delayed by about a week (June 6th -8th) but Skymet suggests that it will be on time and maybe even a day or two early (28th -30th May).

The Skymet prediction seems a little more credible to me. Right now a depression in the Bay of Bengal is bringing very heavy rain to the south-east tip of the peninsula and augurs well for the establishment of the monsoon. The formal “onset of the monsoon” is itself a complex matter. Technically the onset is declared when:

at least 60% of the 14 weather stations across Kerala and coastal Karnataka should record 2.5 mm rainfall or more for two consecutive days.  ….. Simultaneously, the depth of the westerly winds should be up to 600 hPa (or 12000 ft high),  from the equator to 10°N Latitude, and between Longitude 55°E and 80°E. The zonal wind speed over the area bounded by Latitude 5-10°N and Longitude 70-80°E should be around 25 to 35 kmph in the lower levels. The OLR value should also be less than 200 Wm-2 in the box confined by Latitude 5-10°N and Longitude 70-75°E.

While Skymet predicts monsoon conditions being established by end-May, IMD sees that about a week later. Possibly IMD have a smaller initial peak than Skymet.

Skymet’s Jatin Singh writes:

Skymet Weather believes that Monsoon will lash Kerala by the predicted dates between May 28 and 30. …..

…. There are high chances that the onset of Southwest Monsoon in mainland of India will coincide with El Niño reaching the threshold neutral stage. The in-built complex characteristics of Southwest Monsoon are also influenced by external oceanic-atmospheric phenomena like Indian Ocean Dipole (IOD) and Madden-Julian Oscillation (MJO). IOD will remain neutral for now and MJO will also traverse through the favorable zones of eastern Indian Ocean. Therefore, I think that the onset of Monsoon will not be hampered by El Niño, IOD or MJO.

monsoon onset 2016 prediction - graphic Skymet

monsoon onset 2016 prediction – graphic Skymet

Farmers, the government and industry are all looking for a good monsoon to kick-start the Indian economy into a steady period of growth. A “good monsoon” adds – directly and indirectly – about 2 percentage points to GDP. In the present climate where, in spite of the boost from lower oil prices, the Indian economy is dithering about taking off, a “monsoon factor” could be what is needed to secure the upward trajectory.


 

Predictions of a “super” or a “monster” El Niño are fizzling out

August 2, 2014

The latest forecast from the Australian Bureau of Meteorology has now downgraded any El Niño event in 2014 to be  – at worst – a normal or a weak El Niño. There is still a reasonable possibility that it will develop, but that itself means that there is now a significant probability that it may not even happen. The alarmist clamour of 3 months ago, enthusiastically disseminated around the globe was clearly somewhat exaggerated.

ENSO Wrap-Up – 29th July 2014:

Despite the tropical Pacific Ocean being primed for an El Niño during much of the first half of 2014, the atmosphere above has largely failed to respond, and hence the ocean and atmosphere have not reinforced each other. As a result, some cooling has now taken place in the central and eastern tropical Pacific Ocean, with most of the key NINO regions returning to neutral values.

While the chance of an El Niño in 2014 has clearly eased, warmer-than-average waters persist in parts of the tropical Pacific, and the (slight) majority of climate models suggest El Niño remains likely for spring. Hence the establishment of El Niño before year’s end cannot be ruled out. If an El Niño were to occur, it is increasingly unlikely to be a strong event.

Given the current observations and the climate model outlooks, the Bureau’s ENSO Tracker has shifted to El Niño WATCH status.

Back on 6th May, the ABM wrote ” The tropical Pacific Ocean has warmed steadily in recent months, with large warm anomalies in the ocean sub-surface (5-day values up to +6 °C) and increasingly warm sea surface temperatures. Climate models surveyed by the Bureau suggest El Niño development is possible as early as July”.

Climate models are not as robust as some would like us to believe.

The alarmists such as Joe Romm went to town with dire predictions just 3 months ago and were predicting a “super” and a Monster” El Niño for 2014. Of course, dire predictions which never ever materialise are the stuff of alarmism.  The clever alarmist is the one who makes unverifiable predictions which will never happen but which cannot be disproved.

Joe Romm, 26th March: Is A Super El Niño Coming That Will Shatter Extreme Weather And Global Temperature Records?

Signs are increasingly pointing to the formation of an El Niño in the next few months, possibly a very strong one. When combined with the long-term global warming trend, a strong El Niño would mean 2015 is very likely to become the hottest year on record by far. ……. 

John Upton, May 16th: A monster El Niño could be on its way, and it will likely have a complicated effect on the world’s breadbaskets.

Something fierce is rising out of the Pacific Ocean, and its appetite for the world’s major carb crops could be even more ravenous than that of a monstrous mythical sea creature. …… A dinosaurian belch of warm water thousands of miles wide has appeared at the surface of the Pacific Ocean near the equator. The warming ocean conditions have spurred NOAA to project a two-thirds chance that an El Niño will form by summer’s end. It’s tipped to be of the monster variety—the extreme type that could become more common with global warming.

El Niño events come regularly and we can expect that will continue. But in 2014 it will at worst be a “normal” or a weak El Niño. Its feared effects on the Indian monsoon have also been downgraded. The monsoon which is now half-way through its season has recovered somewhat.

But the simple truth is that not a single one of the dire predictions that global warming alarmists are wont to make has come to pass.

In transit with the Indian monsoon

July 3, 2014

I have been traveling this week on an assignment .

Today the monsoon rains reached Delhi –  about 7 days later than the long term average but not an unusual occurrence. A quarter of the 4 month monsoon season is over and so far there is a heavy shortfall in the rainfall received.

Rainfall in July will be crucial in determining whether this monsoon will turn out to be a “bad” one or just somewhat “low”. The risk of this year being a super El Niño year has reduced and with it the risk of a disastrous monsoon has also declined. Nevertheless contingency plans for a “bad” monsoon are being prepared.

Conventional wisdom is that the difference between a good monsoon and a bad one is about 2% points for GDP.

La Niña Strengthens further

October 25, 2010

The NOAA has released its annual winter outlook.

The Pacific Northwest should brace for a colder and wetter than average winter, while most of the South and Southeast will be warmer and drier than average through February 2011. A moderate to strong La Niña will be the dominant climate factor influencing weather across most of the U.S. this winter.

“La Niña is in place and will strengthen and persist through the winter months, giving us a better understanding of what to expect between December and February,” said Mike Halpert, deputy director of the Climate Prediction Center – a division of the National Weather Service. “This is a good time for people to review the outlook and begin preparing for what winter may have in store.”

“Other climate factors will play a role in the winter weather at times across the country,” added Halpert. “Some of these factors, such as the North Atlantic Oscillation, are difficult to predict more than one to two weeks in advance. The NAO adds uncertainty to the forecast in the Northeast and Mid-Atlantic portions of the country.”

This seasonal outlook does not project where and when snowstorms may hit or total seasonal snowfall accumulations. Snow forecasts are dependent upon winter storms, which are generally not predictable more than several days in advance.

 

Winter Outlook - Precipitation

NOAA Winter Outlook: Graphic NOAA

 

The beneficial effects of La Niña on the Indian monsoon have already been seen this year. But after the very cold winter in the Southern Hemisphere it remains to be seen if warm and dry conditions  are established in the South American summer now approaching.

From The Canadian Encyclopedia:

La Niña normally exerts much less of a global impact than El Niño, enhancing conditions that are more or less normal. Thus, under La Niña’s grip, normally wet Indonesia becomes wetter, and winters in Canada are often colder and snowier than normal. However, the weather associated with La Niña tends to be quite variable depending on such factors as its strength, the depth and geographic extent of the cool waters and the pre-existing atmospheric circulation. Among the normal weather effects of La Niña are wetter monsoons and flooding on the Indian subcontinent; torrential rains and floods in southeast Asia and northern and eastern Australia; cool and wet winters in southeastern Africa; and warm and dry conditions along the coast of Peru and Ecuador.

La Niña favours the formation of more and intense hurricanes in the North Atlantic Ocean. Three recent La Niña periods – 1988-89, 1995-96 and 1997-98 – were among the most active periods this century for Atlantic hurricanes.

North America typically feels the effects of La Niña during the winter and early spring. Wetter-than-normal conditions occur across the Pacific Northwest, British Columbia and Alaska. On the other hand, it delivers drier, warmer and sunnier weather along the southern tier of the United States from California through Texas to Florida. Northern states west of the Great Lakes generally experience colder and snowier winters. During La Niña episodes, there is also a greater risk of wildfires in Florida and dryness in the North American plains. The great dust bowl drought of the 1930s is thought to have been caused by a decade of La Niña-like conditions and was likely responsible, in part, for the severe drought in the American midwest in 1988.

During La Niña winters in Canada, the jet stream assumes its more normal mid-continental location. Because the mild air and cold air are never too far away, winters usually comprise alternating bouts of freezing and thawing. Overall, in Western and Central Canada, most La Niña winters tend to be colder than normal by 1 to 2°C, and snowfall amounts are greater than normal from the interior of BC to the St Lawrence Valley. During 8 La Niña episodes since 1950, 6 of the winters across Canada were colder than normal (2 were near-normal) and 7 were snowier than normal.

 

Global La Niña effects: graphic nbc33tv.com

 

 

 


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