Even in restored forests, extreme weather strongly influences wildfire's impacts

The 2013 Rim Fire, the largest wildland fire ever recorded in the Sierra Nevada region, is still fresh in the minds of Californians, as is the urgent need to bring forests back to a more resilient condition. Land managers are using fire as a tool to mimic past fire conditions, restore fire-dependent forests, and reduce fuels in an effort to lessen the potential for large, high-intensity fires, like the Rim Fire. A study led by the U.S. Forest Service's Pacific Southwest Research Station (PSW) and recently published in the journal Forest Ecology and Management examined how the Rim Fire burned through forests with restored fire regimes in Yosemite National Park to determine whether they were as resistant to high-severity fire as many scientists and land managers expected.

Since the late 1960s, land managers in Yosemite National Park have used prescribed fire and let lower intensity wildland fires burn in an attempt to bring back historical fire regimes after decades of fire suppression. For this study, researchers seized a unique opportunity to study data on forest structure and fuels collected in 2009 and 2010 in Yosemite's old-growth, mixed-conifer forests that had previously burned at low to moderate severity. Using post-Rim Fire data and imagery, researchers found that areas burned on days the Rim Fire was dominated by a large pyro-convective plume -- a powerful column of smoke, gases, ash, and other debris -- burned at moderate to high severity regardless of the number of prior fires, topography, or forest conditions.

"The specific conditions leading to large plume formation are unknown, but what is clear from many observations is that these plumes are associated with extreme burning conditions," says Jamie Lydersen, PSW biological science technician and the study's lead author. "Plumes often form when atmospheric conditions are unstable, and result in erratic fire behavior driven by its own local effect on surface wind and temperatures that override the influence of more generalized climate factors measured at nearby weather stations."

When the extreme conditions caused by these plumes subsided during the Rim Fire, other factors influenced burn severity. "There was a strong influence of elapsed time since the last burn, where forests that experienced fire within the last 14 years burned mainly at low severity in the Rim Fire. Lower elevation areas and those with greater shrub cover tended to burn at higher severity," says Lydersen.

When driven by extreme weather, which often coincides with wildfires that escape initial containment efforts, fires can severely burn large swaths of forest regardless of ownership and fire history. These fires may only be controlled if more forests across the landscape have been managed for fuel reduction to allow early stage suppression before weather- and fuels-driven fire intensity makes containment impossible. Coordination of fire management activities by land management agencies across jurisdictions could favor burning under more moderate weather conditions when wildfires start and reduce the occurrences of harmful, high-intensity fires.

View the original article here

Global warming's influence on extreme weather

Understanding the cause-and-effect relationship between global warming and record-breaking weather requires asking precisely the right questions.

Extreme climate and weather events such as record high temperatures, intense downpours and severe storm surges are becoming more common in many parts of the world. But because high-quality weather records go back only about 100 years, most scientists have been reluctant to say if global warming affected particular extreme events.

On Wednesday, Dec. 17, at the American Geophysical Union's Fall Meeting in San Francisco, Noah Diffenbaugh, an associate professor of environmental Earth system science at the Stanford School of Earth Sciences, will discuss approaches to this challenge in a talk titled "Quantifying the Influence of Observed Global Warming on the Probability of Unprecedented Extreme Climate Events." He will focus on weather events that -- at the time they occur -- are more extreme than any other event in the historical record.

Diffenbaugh emphasizes that asking precisely the right question is critical for finding the correct answer.

"The media are often focused on whether global warming caused a particular event," said Diffenbaugh, who is a senior fellow at the Stanford Woods Institute for the Environment. "The more useful question for real-world decisions is: 'Is the probability of a particular event statistically different now compared with a climate without human influence?'"

Diffenbaugh said the research requires three elements: a long record of climate observations; a large collection of climate model experiments that accurately simulate the observed variations in climate; and advanced statistical techniques to analyze both the observations and the climate models.

One research challenge involves having just a few decades or a century of high-quality weather data with which to make sense of events that might occur once every 1,000 or 10,000 years in a theoretical climate without human influence.

But decision makers need to appreciate the influence of global warming on extreme climate and weather events.

"If we look over the last decade in the United States, there have been more than 70 events that have each caused at least $1 billion in damage, and a number of those have been considerably more costly," said Diffenbaugh. "Understanding whether the probability of those high-impact events has changed can help us to plan for future extreme events, and to value the costs and benefits of avoiding future global warming."

View the original article here

Natural variation: Warm North Atlantic Sea encourages extreme winters in U.S. and Europe

The ultimate cold temperature observed across Europe and also the new england of america in recent winters might be partially lower to natural, lengthy-term versions in ocean surface temps, according to a different study released today.

Scientists in the College of California Irvine have proven that the phenomenon referred to as Atlantic Multidecadal Oscillation (AMO) -- an all natural pattern of variation in North Atlantic ocean surface temps that switches between an optimistic and negative phase every 60-70 years -- can impact an atmospheric circulation pattern, referred to as North Atlantic Oscillation (NAO), that influences the temperature and precipitation within the Northern Hemisphere in the winter months.

Once the AMO is within its positive phase and also the ocean surface temps are warmer, the research has proven the primary effect in the winter months would be to promote the negative phase from the NAO which results in "obstructing" episodes within the North Atlantic sector, permitting cold temperature systems to exist within the eastern US and Europe.

The outcomes happen to be released today, Wednesday 2 April, in IOP Publishing's journal Environment Research Letters.

To reach their results, the scientists combined findings in the past century with climate simulations from the atmospheric reaction to the AMO.

Based on their findings, ocean surface temps within the Atlantic can depend on 1.5 ?C warmer within the Gulf Stream region throughout the positive phase from the AMO in comparison towards the negative, cooler phase. The weather simulations claim that these anomalies in ocean surface temps can enjoy a predominant role in marketing the modification within the NAO.

Lead authors from the study Yannick Peings and Gudrun Magnusdottir stated: "Our results indicate the primary aftereffect of the positive AMO in the winter months would be to promote the appearance of the negative phase from the NAO. An adverse NAO in the winter months usually goes hands-in-hands with cold temperature within the eastern US and north-the european union.Inch

The findings also suggest that it requires around 10-fifteen years prior to the positive phase of AMO has any important effect around the NAO. The reason behind this lag is unknown however, a reason may be that AMO phases make time to develop fully.

Because the AMO has been around an optimistic phase because the early the nineteen nineties, it might have led towards the extreme winters that both US and Europe have observed recently.

The scientists warn, however, the future evolution from the AMO remains uncertain, with lots of factors potentially affecting the way it interacts with atmospheric circulation designs, for example Arctic ocean ice loss, alterations in photo voltaic radiation, volcanic eruptions and levels of green house gases within the atmosphere.

The AMO also shows strong variability in one year to another additionally towards the changes seen every 60 - 70 years, which causes it to be hard to attribute specific extreme winters towards the AMO's effects.

Reacting towards the extreme weather that held the eastern coast of america this winter, Yannick Peings ongoing: "Unlike the 2012/2013 winter, this winter had rather low values from the AMO index and also the pattern of ocean surface temperature anomalies wasn't in conjuction with the typical positive AMO pattern. Furthermore, the NAO was mostly positive having a relatively mild winter over Europe."

"It is therefore unlikely the positive AMO performed a determining role around the new england of america, although further jobs are essential to answer this. This kind of event is in conjuction with the large internal variability from the atmosphere, along with other exterior forcings might have performed a job.

"Our future studies will turn to compare the function from the AMO in comparison to Arctic ocean ice anomalies, which are also proven to affect atmospheric circulation designs and promote cooler, more extreme winters."

View the original article here

Extreme weather triggered by global warming decides distribution of bugs, study shows

As global warming is advancing, the temperature in our planet increases. Many of the essential for the big number of creatures which are cold-blooded (ectothermic), including bugs. Their body's temperature is ultimately based on the ambient temperature, and also the same therefore is applicable towards the efficiency and speed of the vital biological processes.

But could it be alterations in climate or frequency of utmost temperature problems that possess the finest effect on species distribution? It was the questions that several Danish and Australian scientists made the decision to look at in many insect species.

Johannes Overgaard, Department of Bioscience, Aarhus College, Denmark, Michael R. Kearney and Ary A. Hoffmann, Melbourne College, Australia, lately released the outcomes of those studies within the journal Global Change Biology. The outcomes demonstrate that it's particularly the extreme temperature occasions that comprise the distribution of both tropical and temperate species. Thus global warming affects ectotermic creatures mainly because more periods of utmost weather are required later on.

Fruit flies were patterned

The scientists examined 10 fruit fly types of the genus Drosophila modified to tropical and temperate parts of Australia. First they examined the temps that the species can sustain growth and reproduction, and they found the limitations of tolerance for cold and hot temps.

"This is actually the very first time ever where we've been in a position to compare the results of extremes and alterations in average conditions inside a rigorous manner across several species," mentions Ary Hoffmann.

According to this understanding and understanding from the present distribution from the 10 species then they examined if distribution was correlated towards the temps needed for growth and reproduction in other words restricted to their ability to tolerate extreme temperature conditions.

"The solution was unambiguous: it's the species' ability to tolerate very hot or cold days that comprise their present distribution," states Johannes Overgaard.

Therefore, it is the ultimate weather occasions, for example prolonged high temperatures or very cold weather, that amounted to the bugs their existence, not a rise in climate.

Drastic changes available

With this particular information in hands, the scientists could then model how distributions are required to alter if global warming continues for the following a century.

Most terrestrial creatures experience temperature variation on daily and periodic time scale, and they're modified to those conditions. Thus, for any species to keep its existence under different temperature conditions you will find two simple conditions that must definitely be met. First of all, the temperature should from time to time be so that the species can grow and reproduce, and next, the temperature must not be so extreme the population's survival is threatened.

In temperate climate for instance, you will find many species that are modified to pass through low temps during the cold months, after which grow and reproduce within the summer time. In warmer environments, the task might be quite contrary. Here, the species might endure high temps throughout the dry hot summer time, while growth and reproduction mainly happens throughout the mild and wet winter period.

The end result was discouraging for those 10 species.

"Global warming can lead to less cold days or weeks, and therefore allow species to maneuver toward greater latitudes. However global warming also results in a greater incidence to very hot days and our model therefore forecasts the distribution of those species will disappear to under half their present distribution"states Johannes Overgaard.

"Actually, our forecasts are that some species would disappear entirely within the next couple of decades, even whether they have a reasonably wide distribution that presently covers 100s of kilometers," adds Ary Hoffmann.

"Although no 10 species analyzed are usually regarded as either dangerous or advantageous microorganisms for human society, the outcomes indicate that distribution of numerous insect species is going to be transformed significantly, and it'll most likely also affect most of the species which have particular social or commercial importance ," finishes Johannes Overgaard.

View the original article here

Get accustomed to prolonged high temperatures: Extreme El Nino occasions to double

Extreme weather occasions fueled by abnormally strong El Ninos, like the 1983 heatwave that brought towards the Ash Wednesday bushfires around australia, will probably double in number as our world warms up.

An worldwide team of researchers from organizations such as the ARC Center of Excellence for Climate System Science (CoECSS), the united states National Oceanic and Atmospheric Administration and CSIRO, released their findings within the journal Character Global Warming.

"We presently receive an abnormally strong El Ni?o event every two decades. Our studies have shown this can double to 1 event every ten years,Inch stated co-author, Dr Agus Santoso of CoECSS.

"El Nino occasions really are a multi-dimensional problem, and just now shall we be beginning to know better the way they react to climatic change," stated Dr Santoso. Extreme El Ni?o occasions develop in a different way from standard El Ninos, which first come in the western Off-shore. Extreme El Nino's occur when ocean surface temps exceeding 28?C develop within the normally cold and dry eastern equatorial Gulf Of Mexico. This different place for the foundation from the temperature

increase causes massive alterations in global rain fall designs.

"The issue of methods climatic change can change the regularity of utmost El Ni?o occasions has challenged researchers in excess of two decades,Inch stated co-author Dr Mike McPhaden people National Oceanic and Atmospheric Administration.

"These studies may be the first comprehensive study of the problem to create robust and convincing results," stated Dr McPhaden.

The impacts of utmost El Ni?o occasions include every region around the world.

The 1997-98 event alone triggered $35-45 US billion in damage and stated an believed 23,000 human lives worldwide.

"Throughout a serious El Ni?o event nations within the western Off-shore, for example Australia and Indonesia, experienced devastating droughts and wild fires, while catastrophic surges happened within the eastern equatorial region of Ecuador and northern Peru," stated lead author, CSIRO's Dr Wenju Cai

Around Australia, the drought and dry conditions caused through the 1982-83 extreme El Ni?o preconditioned the Ash Wednesday Bushfire in southeast Australia, resulting in 75 deaths.

To attain their results, they examined 20 climate appliances consistently simulate major rain fall reorganization throughout extreme El Ni?o occasions. They found a considerable rise in occasions in the present-day with the next a century because the eastern Gulf Of Mexico warmed as a result of climatic change.

"This latest research according to rain fall designs, indicates that extreme El Ni?o occasions will probably double in frequency because the world warms up resulting in direct impacts on extreme weather occasions worldwide."

"For Australia, this might mean summer time prolonged high temperatures, like this lately familiar with the south-east of the nation, might get yet another boost when they coincide with extreme El Ninos," stated co-author, Professor Matthew England from CoECSS.

View the original article here

New phone alerts for extreme weather prevents casualties in India

When Cyclone Phailin hit India at the end of 2013 it grew to become the biggest storm to batter the subcontinent in on the decade. The storm, formally considered a Category 5 tropical cyclone, affected greater than 12 million individuals India and neighboring nations, and needed mass evacuations.

These evacuations revealed a sudden requirement for a highly effective alert system that could forewarn a lot of the population. A brand new paper released in Atmospheric Science Letters particulars how information technology undergraduates have produced image based cell phone alerts, attached to the Weather Research and Predicting system.

India includes a cell phone customer base exceeding 929 million people which is likely to touch 1.15 billion through the finish of 2014. A reminder system produced for mobiles could achieve an believed 97% of people..

The paper particulars how throughout the 2013 storm the pc researchers could track its genesis, progression and landfall. By transforming these details into images appropriate for phones, they produced a predicting and warning system available to regular people.

"Cyclone alerts can help to save lives and property, but should be readily available,Inch stated Dr. Sitting Ghosh. "The worldwide thought of India's emerging IT prowess is uneven. It's regarded as basically a producing hub however, our article puts the nation's statistical literacy to practical use. The simple-to-use Weather Research and Predicting model remains limited for an elite number of customers, for example atmospheric researchers and weather forecasters. Our research explores the way the WRF forecast could be interfaced with mobile telephony with a deep transmission even just in rural pockets asia.Inch

Story Source:

The above mentioned story is dependant on materials supplied by Wiley. Note: Materials might be edited for content and length.

View the original article here

A warming world will further intensify extreme precipitation events

April 4, 2013

Heavy precipitation.

According to a newly-published NOAA-led study in Geophysical Research Letters, as the globe warms from rising atmospheric concentrations of greenhouse gases, more moisture in a warmer atmosphere will make the most extreme precipitation events more intense.

The study, conducted by a team of researchers from the North Carolina State University’s Cooperative Institute for Climate and Satellites-North Carolina (CICS-NC), NOAA’s National Climatic Data Center (NCDC), the Desert Research Institute, University of Wisconsin-Madison, and ERT, Inc., reports that the extra moisture due to a warmer atmosphere dominates all other factors and leads to notable increases in the most intense precipitation rates.

Percent maximum daily preciptation difference (2071-2100) - (1971-2000).

Download here (Credit: NOAA)

The study also shows a 20-30 percent expected increase in the maximum precipitation possible over large portions of the Northern Hemisphere by the end of the 21st century if greenhouse gases continue to rise at a high emissions rate.

“We have high confidence that the most extreme rainfalls will become even more intense, as it is virtually certain that the atmosphere will provide more water to fuel these events,” said Kenneth Kunkel, Ph.D., senior research professor at CICS-NC and lead author of the paper.

The paper looked at three factors that go into the maximum precipitation value possible in any given location: moisture in the atmosphere, upward motion of air in the atmosphere, and horizontal winds. The team examined climate model data to understand how a continued course of high greenhouse gas emissions would influence the potential maximum precipitation. While greenhouse gas increases did not substantially change the maximum upward motion of the atmosphere or horizontal winds, the models did show a 20-30 percent increase in maximum moisture in the atmosphere, which led to a corresponding increase in the maximum precipitation value.

Rainy day.

The findings of this report could inform “design values,” or precipitation amounts, used by water resource managers, insurance and building sectors in modeling the risk due to catastrophic precipitation amounts. Engineers use design values to determine the design of water impoundments and runoff control structures, such as dams, culverts, and detention ponds.

“Our next challenge is to translate this research into local and regional new design values that can be used for identifying risks and mitigating potential disasters. Findings of this study, and others like it, could lead to new information for engineers and developers that will save lives and major infrastructure investments,” said Thomas R. Karl, L.H.D., director of NOAA’s NCDC in Asheville, N.C., and co-author on the paper.

The study, Probable Maximum Precipitation (PMP) and Climate Change, can be viewed online.

NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter and our other social media channels.

View the original article here

Report finds increases in coastal population growth by 2020 likely, putting more people at risk of extreme weather

March 25, 2013

National Coastal Population Report cover.

Download here (Credit: NOAA)

If current population trends continue, the already crowded U.S. coast will see population grow from 123 million people to nearly 134 million people by 2020, putting more of the population at increased risk from extreme coastal storms like Sandy and Isaac, which severely damaged infrastructure and property last year.

The projection comes from a new report released today from NOAA with input from the U.S. Census Bureau.

According to the report, which analyzed data from the 2010 census, 39 percent of the U.S. population is concentrated in counties directly on the shoreline -- less than 10 percent of the total U.S. land area excluding Alaska, and that 52 percent of the total population lives in counties that drain to coastal watersheds, less than 20 percent of U.S. land area, excluding Alaska. A coastal watershed is an area in which water, sediments, and dissolved material drain to a common coastal outlet, like a bay or the ocean.

The National Coastal Population Report: Populations Trends from 1970 to 2020, issued in partnership with the U.S. Census Bureau, updates and expands a 2004 report that detailed and projected coastal population trends from 1980 to 2008.

“People who live near the shore, and managers of these coastal communities, should be aware of how this population growth may affect their coastal areas over time,” said Holly Bamford, Ph.D., assistant NOAA administrator for the National Ocean Service. “As more people move to the coast, county managers will see a dual challenge -- protecting a growing population from coastal hazards, as well as protecting coastal ecosystems from a growing population.”

Population density is growing at the coast.

Download here (Credit: NOAA)

This report offers coastal managers and other users, for the first time, two perspectives on population growth along the U.S. coast -- the traditional perspective that looks at status and trends throughout counties that drain to coastal watersheds, called Coastal Watershed Counties, and a newer focus that focuses only on those counties that directly border the coast, including the Great Lakes.

“Understanding the demographic context of coastal areas is vital for our nation and helps us to meet the challenges of tomorrow. To help inform policymakers and the public through this report, the Census Bureau developed a new measure of coastal populations,” said James Fitzsimmons, assistant chief of the Census Bureau's population division.

Coastal population statistics in the overall total of 769 Coastal Watershed Counties provide context for coastal water quality and coastal ecosystem health related issues, and data from the 452 of those counties that lie directly on the shoreline, called Coastal Shoreline Counties, can be used to talk about coastal resilience, coastal hazards, and other ocean-resource dependent issues.

The coastal shoreline county data was developed with input from both the U.S. Census Bureau and the Federal Emergency Management Agency.

“Whether you’re talking about watershed counties or shoreline counties, the coast is substantially more crowded than the U.S. as a whole,” said report editor Kristen Crossett of NOAA’s National Ocean Service. “Population density in shoreline counties is more than six times greater than the corresponding inland counties. And the projected growth in coastal areas will increase population density at a faster rate than the country as a whole.”

The report also found that from 1970 to 2010, Coastal Shoreline Counties population increased by 39 percent, and Coastal Watershed Counties population increased by 45 percent.

The report is available on NOAA’s State of the Coast website, which provides quick facts and more detailed statistics through interactive maps, case studies, and management success stories that highlight what is known about coastal communities, coastal ecosystems, and the coastal economy and about how climate change might impact the coast.

NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter and our other social media channels.

View the original article here

New analyses find evidence of human-caused climate change in half of the 12 extreme weather and climate events analyzed from 2012

September 5, 2013

The "Explaining Extreme Events of 2012 from a Climate Perspective" report was published today by the Bulletin of the American Meteorological Society. (Full report).

High resolution (Credit: U.S. Navy)

Human influences are having an impact on some extreme weather and climate events, according to the report “Explaining Extreme Events of 2012 from a Climate Perspective” released today by the Bulletin of the American Meteorological Society. Overall, 18 different research teams from around the world contributed to the peer-reviewed report that examined the causes of 12 extreme events that occurred on five continents and in the Arctic during 2012. Scientists from NOAA served as three of the four lead editors on the report.
The report shows that the effects of natural weather and climate fluctuations played a key role in the intensity and evolution of the 2012 extreme events. However, in some events, the analyses revealed compelling evidence that human-caused climate change, through the emission of heat-trapping gases, also contributed to the extreme event.

“This report adds to a growing ability of climate science to untangle the complexities of understanding natural and human-induced factors contributing to specific extreme weather and climate events,” said Thomas R. Karl, L.H.D, director of NOAA’s National Climatic Data Center (NCDC). “Nonetheless, determining the causes of extreme events remains challenging.”

In addition to investigating the causes of these extreme events, the multiple analyses of four of the events — the warm temperatures in the United States, the record-low levels of Arctic sea ice, and the heavy rain in both northern Europe and eastern Australia — allowed the scientists to compare and contrast the strengths and weaknesses of their various methods of analysis. Despite their different strategies, there was considerable agreement between the assessments of the same events.

Thomas Peterson, Ph.D., principal scientist at NOAA’s NCDC and one of the lead editors on the report, said, “Scientists around the world assessed a wide variety of potential contributing factors to these major extreme events that, in many cases, had large impacts on society. Understanding the range of influences on extreme events helps us to better understand how and why extremes are changing."

Key findings include:

Location and type of events analyzed in the Paper.

High resolution (Credit: NOAA)

Heat Wave and Drought in United States:

Human-induced climate change had little impact on the lack of precipitation in the central United States in 2012.The 2012 spring and summer heat waves in the U.S. can be mainly explained by natural atmospheric dynamics, however, human-induced climate change was found to be a factor in the magnitude of warmth and was found to have affected the likelihood of such heat waves.  For example: High temperatures, such as those experienced in the U.S. in 2012 are now likely to occur four times as frequently due to human-induced climate change.Approximately 35 percent of the extreme warmth experienced in the eastern U.S. between March and May 2012 can be attributed to human-induced climate change.  

Hurricane Sandy Inundation Probability:

The record-setting impacts of Sandy were largely attributable to the massive storm surge and resulting inundation from the onshore-directed storm path coincident with high tide. However, climate-change related increases in sea level have nearly doubled today’s annual probability of a Sandy-level flood recurrence as compared to 1950. Ongoing natural and human-induced forcing of sea level ensures that Sandy-level inundation events will occur more frequently in the future from storms with less intensity and lower storm surge than Sandy. 

Arctic Sea Ice:

The extremely low Arctic sea ice extent in summer 2012 resulted primarily from the melting of younger, thin ice from a warmed atmosphere and ocean. This event cannot be explained by natural variability alone. Summer Arctic sea ice extent will continue to decrease in the future, and is expected to be largely absent by mid-century.  

Global Rainfall Events:

The unusually high amount of summer rainfall in the United Kingdom in 2012 was largely the result of natural variability. However, there is evidence that rainfall totals are influenced by increases in sea surface temperature and atmospheric moisture which may be linked to human influences on climate.The magnitude of the extreme rainfall experienced over southeastern Australia between October 2011 and March 2012 was mainly associated with La Niña conditions. However, the likelihood of above-average precipitation during March was found to have increased by 5 percent to 15 percent because of human influences on the climate. Extreme rainfall events such as the December 2011 two-day rainfall in Golden Bay, New Zealand, are more likely to occur due to a 1 percent to 5 percent increase in available moisture resulting from increased levels of greenhouse gases in the atmosphere.The July 2012 extreme rainfall events in North China and southwestern Japan were mainly due to natural variability. 

The report was edited by Peterson, along with Martin P. Hoerling, NOAA’s Earth System Research Laboratory; Peter A. Stott, UK Met Office Hadley Centre and Stephanie C. Herring of NCDC and written by 78 scientists from 11 countries. View the full report online.

NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Join us on Facebook, Twitter, Instagram and our other social media channels.

View the original article here

Recent extreme weather affected 80% of Americans

Violent and deadly weather events have affected more than 240 million Americans — about 80% of the nation's population — over the past six years, says a report out today from an environmental advocacy group.

By Joe Larese, The (Westchester County, N.Y.) Journal News

An SUV attempts to cross a flooded section of Route 9 on Aug. 28 in Cortlandt, N.Y. Hurricane Irene dropped record-breaking amounts of rain in the lower Hudson Valley.

By Joe Larese, The (Westchester County, N.Y.) Journal News

An SUV attempts to cross a flooded section of Route 9 on Aug. 28 in Cortlandt, N.Y. Hurricane Irene dropped record-breaking amounts of rain in the lower Hudson Valley.

Last year was particularly awful for weather in the USA, with at least 14 weather and climate disasters across the nation that each inflicted more than $1 billion in damage. They included a series of devastating tornado outbreaks in the central and southern USA, the ongoing drought in the southern Plains, massive river flooding along the Mississippi and Missouri Rivers, and batterings from Hurricane Irene and Tropical Storm Lee.

Environment America's report looks broadly at county-level weather-related disaster declarations from FEMA for 2006 through 2011 to find out how many Americans live in counties hit by recent weather disasters. The report focused on weather and climate events, and did not include geological events such as earthquakes or volcanic eruptions.

"I think their analysis of the FEMA data is correct," said meteorologist Jeff Masters of the Weather Underground, who was not part of the report.

Whether directly tied to climate change or not, The number of Americans impacted by weather calamities in recent years is sobering:

•From 2006 to 2011, federally declared weather-related disasters have occurred in 2,466 of the 3,068 counties, parishes or boroughs across the USA.

•During that time, weather-related disasters have been declared in every U.S. state except South Carolina.

•Also during this period, weather-related disasters affected every county in 18 states.

If climate change is helping to fuel some of these disasters, as Environment America claims in the report, the group argues the onslaught of catastrophes could become the norm in decades to come.

"Global warming increases the likelihood" of more extreme weather, said Nathan Willcox, Environment America's federal global warming program director.

The United Nations' Intergovernmental Panel on Climate Change (IPCC) last November also reported that disasters such as heat waves, floods and other weather events will likely worsen with global warming.

"Given that global warming will likely fuel even more extreme weather, we need to cut dangerous carbon pollution now," says Willcox. The burning of fossil fuels such as oil, gas and coal — and the resulting release of excess amounts of carbon dioxide — is what's most scientists say is causing global warming. Reducing the output of these "greenhouse" gases is the goal of most environmental groups.

Masters said the report does an "excellent job" highlighting the impacts of climate change on extreme weather.

But connecting specific extreme weather events with climate change is a slippery slope, counters Kristen Averyt, a scientist with the University of Colorado, who was also not part of the report. "Extreme events like the Texas drought are consistent with what we expect in a warmer world, but determining whether climate change caused or exacerbated a specific event is not easy.

"The answers are not just about mitigating greenhouse gas emissions — they're also about adaptation to events and reducing our vulnerabilities," she says.

For more information about reprints & permissions, visit our FAQ's. To report corrections and clarifications, contact Standards Editor Brent Jones. For publication consideration in the newspaper, send comments to letters@usatoday.com. Include name, phone number, city and state for verification. To view our corrections, go to corrections.usatoday.com.

View the original article here

Billion-Dollar Disasters 'Harbinger' of Future Extreme Weather: NOAA (LiveScience.com)

SAN FRANCISCO — The 12 $1-billion-plus disasters that hit the United States this year are most likely not simply a matter of the stars aligning against us, according to the head of the National Oceanic and Atmospheric Administration (NOAA), who implicated climate change as a contributor. 

Climate change, caused by carbon dioxide and other greenhouse gases humans have emitted, is expected to increase certain types of extreme weather, leading to more disasters, according to a report being assembled by the Intergovernmental Panel on Climate Change (IPCC).

"The report that was released by the IPCC on extreme events suggests that what we are seeing this year is not just an anomalous year, but a harbinger of things to come for at least a subset of the extreme events we are tallying,"said Jane Lubchenco, NOAA's administrator, during a press conference held here this week at the annual American Geophysical Union meeting.

A summary of the report released in November predicts an increase in certain types of extreme weather, including daily high temperatures, heat waves, heavy precipitation and droughts, in some places. [Photos of Devastating Texas Drought]

Costly disasters

With this increase in extreme weather there will likely be an associated uptick in costs. Earlier Wednesday (Dec. 7) the agency announced that this year, so far, had broken the record for costly, weather-related disasters,including drought, wildfire, tornados, flooding, a blizzard and a hurricane. She noted that the agency is still tallying costs related to Tropical Storm Lee and the unseasonable snowstorm in the Northeast that occurred over Halloween weekend.

"I believe there are probably four reasons why we are seeing an increase," said Lubchenco, referring to the number of costly events. "One is there are more extreme events, period, but it is more complicated than that," Lubchenco said, adding that the country now has more people, who have more stuff to lose in disasters, and more people and their stuff now reside in harm's way, such as along the coasts. More people also have insurance that pays for their losses, magnifying the costs associated with a disaster.  

The previous record, for nine $1-billion-or-more weather-related disasters was set in 2008.

Climate-change connection

Of the types of extremes that battered the country this year, only certain large-scale phenomena among them —such as heat waves, droughts and heavy precipitation —have links to climate change.

"We are likely to see more and more of them down the road as climate continues to change," she said.

The connection between small-scale extreme events, such as a localized hailstorm or a tornado, and climate change is less understood, she said.

Since about 1970, NOAA's Climate Extreme Index —which tracks the percentage of the country affected by climate extremes over time —has shown an upward trend that is notably different than the activity in earlier decades, she told an audience of scientists at a talk earlier in the day.

This trend is driven by daily highs and lows, availability of water and heavy precipitation in a single day. Most notably, since 1970, more of the country is experiencing unusually warm nights, with less of the country experiencing unusually cool nights. This particular shift is significant, she said: "Warm overnight lows are related to heat stress in both people, and plants and animals; they never get a chance to cool off."

Likewise, while the country has had periods of severe drought, such as during the Dust Bowl of the 1930s, it has never become drier and wetter at the same time, as has happened in the last decade, she said.

You can follow LiveScience senior writer Wynne Parry on Twitter @Wynne_Parry. Follow LiveScience for the latest in science news and discoveries on Twitter @livescience and on Facebook.

View the original article here

Extreme weather to worsen with climate change: IPCC (Reuters)

KAMPALA (Reuters) – An increase in heat waves is almost certain, while heavier rainfall, more floods, stronger cyclones, landslides and more intense droughts are likely across the globe this century as the Earth's climate warms, U.N. scientists said on Friday.

The U.N. Intergovernmental Panel on Climate Change (IPCC) urged countries to come up with disaster management plans to adapt to the growing risk of extreme weather events linked to human-induced climate change, in a report released in Uganda on Friday.

The report gives differing probabilities for extreme weather events based on future greenhouse gas emissions scenarios, but the thrust is that extreme weather is likely to increase.

"It is virtually certain that increases in the frequency and magnitude of warm daily temperature extremes ... will occur in the 21st century on the global scale," the IPCC report said.

"It is very likely that the length, frequency and/or intensity of warm spells, or heat waves, will increase," it added.

"A 1-in-20 year hottest day is likely to become a 1-in-2 year event by the end of the 21st century in most regions," under one emissions scenario.

An exception is in very high latitudes, it said. Heat waves would likely get hotter by "1 degrees C to 3 degrees C by mid-21st century and by about 2 degrees C to 5 degrees C by late-21st century, depending on region and emissions scenario."

Delegates from nearly 200 countries will meet in South Africa from November 28 for climate talks with the most likely outcome modest steps toward a broader deal to cut greenhouse gas emissions to fight climate change.

CARBON EMISSIONS UP

The United Nations, the International Energy Agency and others say global pledges to curb emissions of CO2 and other greenhouse gases are not enough to prevent the planet heating up beyond 2 degrees Celsius, a threshold scientists say risks an unstable climate in which weather extremes become more common and food production more difficult.

Global carbon emissions rose by a record amount last year, rebounding on the heels of recession.

"It is likely that the frequency of heavy precipitation or the proportion of heavy rainfall from heavy falls will increase in the 21st century over many areas of the globe," especially in "high latitudes and tropical regions."

For the IPCC, "likely" means a two-thirds chance or more.

It said there was "medium confidence" that this would lead to "increases in local flooding in some regions", but that this could not be determined for river floods, whose causes are complicated.

The report said tropical cyclones were likely to become less frequent or stay the same, but the ones that do form are expected to be nastier.

"Heavy rainfalls associated with tropical cyclones are likely to increase with continued warming. Average tropical cyclone maximum wind speed is likely," the report said.

That, coupled with rising sea levels were a concern for small island states, the report said.

Droughts, perhaps the biggest worry for a world with a surging population to feed, were also expected to worsen.

The global population reached 7 billion last month and is expected to reach 9 billion by 2050, according to U.N. figures.

"There is medium confidence that droughts will intensify in the 21st century ... due to reduced precipitation and/or increased evapotranspiration," including in "southern Europe and the Mediterranean region, central Europe, central North America, Central America and Mexico, northeast Brazil and southern Africa."

There is a high chance that landslides would be triggered by shrinking glaciers and permafrost linked to climate change, it said.

(Writing and additional reporting by Tim Cocks; Editing by Janet Lawrence)

View the original article here

Extreme weather in the Bay Area through the years (ContributorNetwork)

On the West Coast, San Francisco Bay Area residents enjoy mild days with temperatures in the 60s and 70s. We aren't always this lucky, however. Records show more than 60 years of bad weather for Bay Area residents, including droughts, floods, tornadoes, and snowstorms.

Bay Area drought

Many remember a few short years ago when the Bay Area had one of the worst single drought years on record. The 2009 drought caused unprecedented water rationing with reservoir levels at all-time lows.

Other drought years include:

- 1975-1977: 1976 was recorded by the California Department of Water Resources as "one of the driest years on record." The drought then continued into 1977. This drought had significant impacts on agriculture, recreation, and rangeland herds.

- 1987-1993: This longest-running drought was the most severe in California history. The drought actually began breaking in December of 1992. It was officially declared "over" when flooding from December 1992 to February 1993 brought almost 200 percnet of annual rainfall, according to a 1993 report by the California Department of Water Resources.

Bay Area floods

The California Office of Emergency Services recorded many significant years of heavy rainfall and flooding between 1950 and 2010. Two of the most deadly were reported in 1955 and 1969, when a combined total of 121 lives were lost.

Other significant floods reported:

- 1982-1983: This was the year of El Nino. The flood caused levee failure in several northern counties.

- 1992-1993: Severe flooding preceded a drought.

- 1995 to 1996: These years brought heavy winter storms and unprecedented damages. 1995 alone cost nearly $2 billion in damage.

- 1997: Another El Nino year. This flood year cost $1.8 billion.

- 1998: Flooding continues, costing $550 million.

Tornadoes hit the Bay Area

Of the 379 California tornadoes recorded by The Tornado History Project between 1951 and 2010, 17 appeared in seven of the nine counties in the Bay Area. During that time, Napa and San Francisco County remained unaffected until 2011. San Francisco County's historic tornado clocked in as No. 18 in the Bay Area.

Other tornadoes recorded:

- 1958: The California tornado with the longest path during 1951-2010 started near Bodega Bay and ran 15 miles towards Santa Rosa.

- 1998: An F-2 tornado in Sunnyvale "was the first anticyclonic supercell and anticyclonic tornado to be documented with the WSR-88D NEXRAD radar," according to USA Today.

- 2011: An EF 1 tornado touched down in Santa Rosa, leaving a block-long debris trail and demolishing the roof of a local business. That same day, a waterspout was recorded off Ocean Beach.

Snowstorms in the Bay Area

While snow is a rare event at sea level in the Bay Area, we've had a few decent storms over the years. Snowstorms in the Bay Area have been recorded as early as 1882.

Other snowstorms include:

- 1951: Based on photos, this snowstorm appeared to be the "heaviest of the 20th century in San Francisco," according to SFGate.

- 1962: A snowstorm closed local schools and roads. "I remember we got out of school and spent the day playing in the snow," recalled Brian Wrede, a student in 1962 at Noddin Elementary in San Jose.

- 1976: A freak snowstorm hits the Bay Area, closing local roads and schools.

- 2011: We all remember last year when freezing temperatures and a light sprinkling of snow fell in the Bay Area, including Morgan Hill and Gilroy. It melted quickly, however, and wasn't enough to make a snowball.

View the original article here

Accuweather forecasts extreme cold winter for Chicago (Reuters)

(Reuters) – Private forecaster Accuweather.com said on Wednesday that heavy snow and extreme cold should be expected in the north central United States, especially in the Chicago area, in the coming winter.

The East Coast faces average to slightly above average snowfall during the winter of 2011-2012 as a Pacific La Nina again drives weather patterns across the United States.

"People in Chicago are going to want to move after this winter," Accuweather Long-Range Meteorologist Josh Nagelberg said in a statement.

Accuweather's forecast projects Chicago will again be hit by extreme cold weather and several blizzards, as it endured last winter when more than 50 inches fell on the city including a single storm that dropped 20 inches.

Severe cold and heavy snow should expected from the Great Lakes across the Midwest and northern plains states, according to Accuweather.

La Nina, the name for a recurring phenomenon when sea surface temperatures across the central and eastern Pacific Ocean are below normal, will fuel weather across North America, including a persistent flow of tropical moisture that brings heavy rains to the West Coast called the "Pineapple Express."

The southeastern United States could again see flooding in the lower Mississippi Valley in late winter, Accuweather said.

Dry, mild weather is expected over most of the southwestern United States, with no relief seen for drought-stricken Texas.

The Mid-Atlantic states could see snow and ice with South Carolina and Georgia seeing rain. Florida should expect a mild, dry winter.

(Reporting by Erwin Seba in Houston; Editing by Gary Hill)

View the original article here

U.S. sees growing losses from extreme weather (Reuters)

MIAMI (Reuters) – The United States has already tied its yearly record for billion-dollar weather disasters and the cumulative tab from floods, tornadoes and heat waves has hit $35 billion, the National Weather Service said on Wednesday.

And it's only August, with the bulk of the hurricane season still ahead.

"I don't think it takes a wizard to predict 2011 is likely to go down as one of the more extreme years for weather in history," National Weather Service Director Jack Hayes told journalists on a conference call.

The agency's parent organization, the National Oceanic and Atmospheric Administration or NOAA, launched a campaign on Wednesday to better prepare Americans for violent weather.

There have so far been nine separate disasters this year that caused an economic loss of $1 billion or more in the United States, tying the record set in 2008, NOAA said. The most recent was the summer flooding along the Missouri and Souris rivers in the upper Midwest.

The "new reality" is that both the frequency and the cost of extreme weather are rising, making the nation more economically vulnerable and putting more lives and livelihoods at risk, Hayes said.

The number of U.S. natural disasters has tripled in the last 20 years and 2010 was a record breaker with about 250, according to property and casualty reinsurer Munich Reinsurance America.

Average thunderstorm losses have increased five-fold since 1980. For the first half of 2011 there have been $20 billion in thunderstorm losses, up from the previous three-year average of $10 billion, NOAA said.

The rising costs are due partly to demographics, Hayes said. The population is rising and there are more people and more buildings in environmentally vulnerable areas, such as coastal regions.

CLIMATE CHANGE?

Asked if global warming was to blame for the rising frequency of wild weather, Hayes said that was "a research question" and that it would be difficult to link any one severe season to overall climate change.

NOAA's effort to make America "weather-ready" is aimed at producing earlier, more precise warnings and helping people understand what to do to protect themselves, Hayes said.

In the current fiscal climate, it mainly focuses on already-budgeted items such as upgrading the weather radar system and on better coordination among existing agencies.

For example, one program aims to have rainfall forecasters work more closely with the agencies that build and maintain levees and operate flood-control canals.

Other steps include:

-Helping communities stage disaster preparedness drills.

-Dispatching specially trained meteorologists to emergency response centers during disasters such as wildfires.

-Asking behavioral scientists for advice on how to improve the wording of advisories so that the general public understands them, and how to deter risky behavior such as driving onto flooded roads.

-Expanding the use of social media such as Facebook, Twitter and chatrooms to help spread weather warnings.

NOAA's warning was timed with the advent of what is traditionally the busiest part of the June-through-November Atlantic hurricane season. The United States has not been hit by a hurricane in three years.

"Those are the types of things that lull people to sleep. We want people vigilant," Hayes said.

NOAA has predicted there will be as many as 19 tropical storms this year. So far there have been seven, but none have strengthened into hurricanes. Only one, Tropical Storm Don, came ashore in the United States but it quickly fizzled over the Texas coast without delivering the rain that is badly needed in the parched state.

(Editing by Cynthia Osterman)

View the original article here

More extreme weather in store across U.S. (Reuters)

ST. PETERSBURG, Fla (Reuters) – More extreme weather was expected across the country on Sunday, as parts of the Midwest and Northeast faced possible flooding from slow-moving storms while blistering triple-digit temperatures were expected in coastal Southeastern states.

A strong, westerly wind flowing down from the Appalachian Mountains will briefly push temperatures in Virginia, the Carolinas and Georgia over the century mark in the afternoons on Sunday and Monday, according to AccuWeather.com.

The temperature will feel like 110 to 115 degrees Fahrenheit with the humidity.

After dumping rains on the Bahamas, the remnants of former Tropical Storm Emily moved into the open Atlantic and away from the U.S. East Coast on Sunday as a tropical depression.

The remaining clouds and thunderstorms carried top sustained winds of 35 miles per hour with little change in strength expected over the next 24 hours, the U.S. National Hurricane Center said.

AccuWeather.com meteorologists predicted a stormy day in the Midwest and Northeast, with the I-95 corridor from the Baltimore area north to New York City seen as particularly vulnerable to flooding from heavy rains.

"Because many in this region experienced heavy rain on Saturday and overnight, the threat for flooding in low-lying and poor drainage areas will be elevated as any heavy shower or storm rolls through," AccuWeather.com meteorologist Bill Deger said on the website.

The American Red Cross on Sunday said nearly 100 homes had been damaged by flash floods in Charlotte, North Carolina, on Friday.

Authorities had recovered the bodies of a 43-year-old woman and her 16-year-old daughter, who appeared to have drowned in a creek swollen by heavy rains in east Charlotte.

HIGH HEAT CONTINUES

Heat advisories remain in effect in the South and Central Plains, which have been baking for weeks in high heat that shows little sign of subsiding.

In New Orleans, organizers of the annual music festival honoring jazz legend Louis "Satchmo" Armstrong dubbed the event as "Satchmo in the Shade" this weekend after erecting massive tents to help keep attendees cool in the 90-degree heat.

Temperatures well into the triple digits are forecast over a large area of central and western Texas for the coming week.

The Weather Channel predicts highs by midweek of 109 degrees in the Dallas-Fort Worth area, which already has sweltered through 36 consecutive days of temperatures topping 100 degrees.

The state's power grid is being pushed to the limit by the widespread nature of the heat. Residents are being urged to turn their air conditioning units up to 80 degrees and avoid using appliances such as dishwashers or laundry equipment, especially during the late afternoon.

"They are not only your hottest times of the day, but they are also the times of the day when not only is the workplace still active, but people are heading home and using more electricity there as well," said Terry Hadley, a spokesman for the Public Utility Commission of Texas.

Meanwhile, parts of the Midwest are on the verge of breaking out of the prolonged heat grip, the National Weather Service said.

In Kansas City, Missouri, where the city's health department says 24 people have died this summer from heat-suspected causes, the forecasted high of 95 degrees on Sunday is expected to give way to highs in the middle to low 80s for the rest of the week starting Monday.

(Additional reporting by Kevin Gray in Miami, Jim Forsyth in San Antonio, Kevin Murphy in Kansas City and Kathy Finn in New Orleans; Editing by Jerry Norton)

View the original article here