Showing posts with label LA NIñA. Show all posts
Showing posts with label LA NIñA. Show all posts

LA NIñA CONFIRMED...ANOTHER YEAR OF "UNUSUAL" WEATHER...

La Nina returns, bringing more severe weather: US

by Staff Writers
Washington (AFP) Sept 8, 2011





The weather phenomenon known as La Nina is returning for another season, likely bringing more drought, heavy rains and severe weather to some parts of the world, US forecasters said Thursday.

Experts at the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center upgraded last month's La Nina Watch to a La Nina Advisory, the agency said in a statement.

The back-to-back emergence of the trend -- which causes cooler than average temperatures in the Pacific Ocean -- is not unheard of and happens about half the time, NOAA said.

"La Nina, which contributed to extreme weather around the globe during the first half of 2011, has re-emerged in the tropical Pacific Ocean and is forecast to gradually strengthen and continue into winter," it said.

The June 2010 to May 2011 La Nina "contributed to record winter snowfall, spring flooding and drought across the United States, as well as other extreme weather events throughout the world, such as heavy rain in Australia and an extremely dry equatorial eastern Africa."

Over 12 million people across the Horn of Africa are reeling from the region's worst drought in decades, which led the United Nations in July to declare the first famine this century.

The weather pattern was blamed for extremely heavy downpours in Australia, Southeast Asia and South America over late 2010 and early 2011.

"This means drought is likely to continue in the drought-stricken states of Texas, Oklahoma and New Mexico," said Mike Halpert, deputy director of the Climate Prediction Center.

The northwestern United States can brace for a colder winter than usual while southern US states should see a warming trend, he said.

Pacific summit sounds alarm on climate change
Auckland (AFP) Sept 8, 2011 - Pacific leaders identified climate change as the greatest threat to the region Thursday, ordering officials to start work on plans to help people forced to relocate by rising sea levels.

The 16-nation Pacific Islands Forum said the impact of climate change was already apparent in countries such as Kiribati, where some villagers have had to abandon their homes as the seas rise, and finance was needed to help them.

"Climate change remains the single greatest threat to the livelihoods, security and well-being of the peoples of the Pacific," said a communique issued by the regional grouping after a two-day summit in Auckland.

The communique, which also raised concerns about human rights in Fiji, thanked UN Secretary-General Ban Ki-moon for travelling to Auckland this week to highlight the threat posed by climate change.

During his visit, the UN leader said he had seen the effect of global warming first-hand during a visit to Kiribati and it had reinforced his belief that climate change was a reality.

"Climate change is not about tomorrow," he said during his Auckland visit. "It is lapping at our feet -- quite literally in Kiribati and elsewhere."

The PIF leaders ordered a report into how relocation options could be financed in a region where many island nations rely heavily on foreign aid, taking into account "the specific capacities and needs of respective countries".

They said there was a "critical and urgent need" for finance to help Pacific countries "in particular those already suffering, (who) are displaced or are being displaced as a result of the detrimental impacts of climate change".

During the summit, Kiribati President Anote Tong revealed that his low-lying nation was considering radical solutions to deal with rising seas, such as moving its 100,000-strong population onto man-made floating islands.

He estimated that the plan, which would see Kiribati residents relocated to structures resembling oil rigs, would cost $2 billion.

The PIF report into how to pay for relocation options is scheduled for completion in the first quarter of next year.

On Fiji, which was expelled from the PIF two years ago after its military regime reneged on plans to hold elections in the wake of a 2006 coup, the PIF countries reiterated the need for a return to democracy.

"(PIF leaders) expressed their continuing deep concern at the deteriorating human rights situation and serious political and economic challenges facing the people of Fiji," the communique said.

However, earlier on Thursday, European Commission president Jose Manuel Barroso, who also visited Auckland for the summit, said he saw few signs the regime was easing its grip on power.

"Today we see little, if any, positive developments (in Fiji). The repressive regime remains in place, the socio-economic situation has worsened," he said in a speech at Auckland University.

"Against this background there is an evident need for supporting the Fijian people but keeping the pressure on the regime.

"That is why we will continue our search for a solution that returns democracy to the people of Fiji."

While the PIF meeting formally ended with the release of the communique, high-level talks will continue Friday when member nations hold bilateral talks with VIP guests in Auckland for the gathering.

US Deputy Secretary of State Tom Nides arrived with a 50-strong delegation Thursday, saying President Barack Obama had personally ensured that Washington had top-level representation at the meeting.

"Without question, the President is very much focused on what we're doing in this region and more importantly showing our deep and everlasting friendship with our friends in New Zealand," he told reporters.

Other high-profile dignitaries in Auckland include French Foreign Minister Alain Juppe, Commonwealth Secretary-General Kamalesh Sharma and China's Vice Foreign Minister Cui Tiankai.




IF LA NIñA RISK INCREASES FOR AFRICA...DOES THAT MEAN AN EL NIñO FOR SOUTH AMERICA ???...THE NEXT FEW WEEKS WILL GIVE US A BETTER IDEA...

La Nina risks increase, to detriment of E. Africa: UN


by Staff Writers
Geneva (AFP) Sept 1, 2011





There is a 50 percent chance the climatic condition known as La Nina -- which is associated with droughts in East Africa -- will return this year, the UN weather agency said Thursday.

"We are increasing the probability of La Nina from 25 to 50 percent," Rupa Kumar Kolli, a climate expert at the World Meteorological Organization said, explaining that the rise was due to recent temperature observations in the Pacific.

"La Nina is associated with drought conditions in east Africa. The last La Nina situation was believed to have caused the drought condition in the greater Horn of Africa," he told reporters, referring to the La Nina event which ended in May.

He however stressed that meteorological predictions were difficult to make and depended on a variety of local conditions.

"And even if a La Nina situation reemerges, it is very likely it will be a very weak La Nina event," Kolli explained.

Over 12 million people across the Horn of Africa are reeling from the region's worst drought in decades, which led UN in July to declare the first famine this century.

According to a WMO press statement, La Nina is characterised by "unusually cool ocean surface temperatures in ... the central and eastern tropical Pacific."

The weather pattern was blamed for extremely heavy downpours in Australia, southeast Asia and sSouth America over late 2010 and early 2011, the WMO said in May.

Although the ocean temperatures in the Pacific leveled to their long-term, or "neutral" conditions that month, "observations during recent weeks indicate a drift toward the cool side ... in terms of surface as well as subsurface ocean temperatures," WMO said today.

"If this cooling persists ... for another few weeks then we will be going into another la Nina situation," Kolli said.

"For (the Horn of Africa), this can be understood as a cause for additional alert," Kolli added.




THE EL NIñO / LA NIñA CYCLE HAS BEEN AROUND FOR THOUSANDS OF YEARS AND IS BEING STUDIED IN AFRICA...

La Ninas distant effects in East Africa

by Staff Writers
Potsdam, Germany (SPX) Aug 05, 2011


GFZ-Scientists analyse sediments in the Challa-Lake, a crater lake at the Kilimandjaro.



For 20 000 years, climate variability in East Africa has been following a pattern that is evidently a remote effect of the ENSO phenomenon (El Nino Southern Oscillation) known as El Nino/La Nina. During the cold phase of La Nina, there is marginal rainfall and stronger winds in East Africa, while the El Nino warm phase leads to weak wind conditions with frequent rain.


Moreover, during the coldest period of the last ice age about 18 000 to 21 000 years ago, East Africa's climate was relatively stable and dry. This result was published by an international group of researchers from Potsdam, Switzerland, the United States, the Netherlands and Belgium in the latest issue of the journal "Science" (Vol. 333, No.6043, 05.08.2011).

ENSO with its warm phase (El Nino) and its cold phase (La Nina) is actually known as a climate phenomenon in the Pacific with global teleconnections. Using the example of climate variability in East Africa, the study shows the long-term impact of this phenomenon in this sensitive region.

The sediments in Lake Challa in southeastern Kenya, at the foot of Mount Kilimanjaro, serve as a climate archive. Sample cores that were drilled here show a pattern of stripes, so called annual laminae. Each individual layer holds information about the climate.

"The thickness of these layers varies according to the climate, from 0.08 to 7 millimeters," explains Christian Wolff (University of Potsdam and GFZ German Research Centre for Geosciences). "A comparison of temperature measurements in the tropical Pacific over the last 150 years shows a strong correlation between ENSO cycles and the rhythms of droughts and floods in East Africa."

That is to say, two climate patterns are superimposed here. The basic rhythm is provided by the annual rainy seasons, which are linked to the so-called Intertropical Convergence Zone (ITCZ). This refers to the band of clouds near the equator, which is formed by sunlight and excessive evaporation.

With the sun high in June on the northern hemisphere and in December in the southern hemisphere, this band of clouds and the rain associated with it moves north- or southwards, respectively. This seasonal event is apparently superimposed by the ENSO phenomenon.

The length of the drill core allowed the tracking of climate variations to the last ice age. Biogeochemical proxy data and careful seismological exploration of the sediment layers brought together a very good agreement with the thicknesses of individual layers.

It was found that even in the last glacial, when the world was about 5 degrees colder globally and thus the energy budget of the tropics system was smaller due to lower temperature, the ENSO phenomenon was seen as a superimposed pattern, albeit weaker.

In comparison, the last 3000 years were warmer and more volatile, with intensive dry and drought periods, as this year, and massive rainy periods, which frequently lead to flooding. Climate models show that this trend towards an increase in extreme dry and wet phases continues on in a warming world.

The study was funded by the DFG German Research Foundation, the ESF European Science Foundation and the U.S. National Science Foundation NSF. Christian Wolff et al.: "Reduced Interannual Rainfall Variability in East Africa During the Last Ice Age", Science, Vol. 333, No.6043, 05.08.2011



TROPICAL STORMS EXPECTED TO PICK UP INTENSITY BETWEEN NOW & NOVEMBER...BRACE FOR ANOTHER DOZEN BY THE END OF SEASON...


Forecasters predict unusually active hurricane season

The National Oceanic and Atmospheric Administration is expecting seven to 10 hurricanes, with three to five carrying winds upward of 111 mph.


Two people ride in a motorcycle covered by an umbrella in Santo Domingo, Dominican Republic August 4, 2011 after the heavy rains that came with the tropical storm Emily. (Orlando Barra / EPA)




ALSO
Haitians anxious as Tropical Storm Emily nears
Graphic: Tropical storm Emily pounds Caribbean
Eugene becomes a 'major hurricane' off Baja California


                                                                                                                      Graphic: Ocean temperature data


By Stephen Ceasar, Los Angeles Times

August 5, 2011



Exceptionally warm ocean waters and favorable atmospheric conditions are expected to bring an above-average number of tropical storms and hurricanes to the Atlantic and Caribbean, national weather forecasters predicted Thursday.


The forecast comes as Florida braces for the remnants of Tropical Storm Emily, which has pounded the Caribbean in recent days with rain and winds above 50 mph. 


The storm weakened considerably Thursday, but is expected to bring some rain and winds to Florida over the weekend.

In its latest outlook, the National Oceanic and Atmospheric Administration raised the number of hurricanes to between seven and 10 — including three to five major hurricanes with winds of at least 111 mph. 


In May, the agency predicted six to 10.

Altogether, forecasters predict 14 to 19 tropical storms, which include the hurricanes. 


In May, forecasters predicted 12 to 18 tropical storms. 


The figure includes the five tropical storms that have already formed since the beginning of the season June 1. 


The season ends Nov. 30.


Forecasters point to the convergence of several factors in May that bolstered the increased predictions:

A combination of favorable oceanic and atmospheric conditions in the tropics has created a high-activity era since 1995. This, paired with the third warmest water temperatures on record, the possible redevelopment of La Niña, and reduced vertical wind shear and lower air pressure across the tropical Atlantic, has the area poised for a more active season.


"The atmosphere and Atlantic Ocean are primed for high hurricane activity during August through October," said Gerry Bell, lead seasonal hurricane forecaster at NOAA's Climate Prediction Center in Washington.


 "Storms through October will form more frequently and become more intense than we've seen so far this season."


The seasonal outlook has proved beneficial in stating how many storms, hurricanes and major hurricanes will occur over the six-month hurricane season. But it does little in the way of predicting details of devastating storms, said Dennis Feltgen, spokesman for National Hurricane Center in Miami.

"The seasonal outlook cannot tell you when they're going to form, where they're going to form or, more importantly, where they're going to strike land," Feltgen said. "If that one storm hits you, it's a really bad year."

In 2010, the Atlantic and Caribbean experienced above-normal hurricane activity, but none made landfall in the United States.

The last hurricane to hit land in the United States was Hurricane Ike in 2008, which caused $10 billion in damage across Texas, Arkansas and Louisiana, the hurricane center said.

stephen.ceasar@latimes.com


Copyright © 2011, Los Angeles Times