09 Feb 2015: Analysis

As Extreme Weather Increases,
A Push for Advanced Forecasts

With a warmer atmosphere expected to spur an increase in major storms, floods, and other wild weather events, scientists and meteorologists worldwide are harnessing advanced computing power to devise more accurate, medium-range forecasts that could save lives and property.

by cheryl katz

Like a pipeline in the sky, the plume of sodden tropical air advanced mile-high above the Pacific Ocean, heading toward the California coast. This “atmospheric river” — a long, narrow band of concentrated water vapor — carried the moisture equivalent of about 15 Mississippi Rivers. When it made landfall, it dumped a massive amount of rain on the densely populated stretch of California from San Francisco to Los Angeles, unleashing floodwaters, causing landslides, and cutting off power to hundreds of thousands of homes and businesses.

Atmospheric rivers fuel some of western North America’s most intense and destructive winter storms, and this one, slamming California last December, was a big one. But despite nearly a foot of rain in some places, damage was considerably less than it could have been, thanks to forecasts that pinpointed the storm’s course a week before it struck, giving communities time to prepare.

“I think that [forecast] was a home run,” said Mike Dettinger — a research hydrologist with the U.S. Geological Survey (USGS) and Scripps Institution of Oceanography in La Jolla, California — who studies atmospheric rivers. “That is how we feel the forecasts ought to work for us now.”

View Gallery
Atmospheric river

NOAA/ESRL Physical Sciences Division
The arrival of a so-called atmospheric river on the West Coast of the U.S. and Canada in December 2014. The storm dropped massive amounts of rain on drought-stricken California.


Early warnings for extreme weather like atmospheric rivers will be increasingly crucial in coming years as global warming keeps temperatures on the rise. A hotter planet will pump more energy into the atmosphere, setting off more extreme heat waves, lengthy droughts, intense storms, and other “high impact” events that can cause major property damage, economic havoc, widespread injury, and death. More frequent weather extremes could also trigger disease outbreaks, jeopardize food security and water availability, and even lead to political instability and civil unrest.

Advanced forecasting can help avert disasters, say scientists, who are harnessing unprecedented computing power, enhancing mathematical models, and devising new observation methods to provide better and
Tiny errors at the beginning of a forecast can lead to wide misses by the end.
longer-term forecasts for the stormier times ahead.

“Improving our forecast capabilities is incredibly important,” said Paul Higgins, a climate scientist and policy director of the American Meteorological Society. “There’s the potential to improve monitoring and be able to identify when problems could occur. It helps protect life and property [and] allows us to reduce the risks that we face from high-impact weather.”

Most forecasts today can see clearly only a few days ahead. It all hinges on the performance of computer models that assimilate observations from sources like satellites, radar, and weather stations into numerical simulations that are run forward to predict future conditions. Lengthen the lens and the focus gets blurred by model discrepancies and uncertainty, observation error, and the complex physics of weather. A model may be able to project a likely torrential downpour 10 days off, for instance, but lacks resolution fine enough to tell more precisely where the storm will strike until it’s two or three days away, leaving communities scrambling to prepare.

Even then, tiny errors at the beginning of a forecast can lead to wide misses by the end — one of the reasons the monster blizzard prediction that launched a pre-emptive shutdown of New York City last month was so far off the mark. That forecast was further skewed by disagreement between the two most widely used weather models: one developed by the U.S. Weather Service and the other by the European Center for Medium-Range Weather Forecasts. Needing to make a quick decision as the storm bore down, forecasters went with the European model, based on its better track record for predicting Hurricane Sandy and other recent events. This time, however, the U.S. model was more accurate.

To allow more time for complex decisions and preparations in the face of rising weather threats, scientists are now looking to medium-range forecasting — predicting high-impact events one to two weeks in advance — and are devising new tools and technologies to sharpen their weather vision. These include beefed-up supercomputers crunching complex algorithms; seven- to 14-day heat wave and gale predictions;
‘In a changing climate, it’s important to be able to anticipate how much water might be available in the future.’
high-resolution models with a more dense data grid on location, altitude, and time; and better accounting for uncertainty.

Medium-range forecasting efforts are gearing up across the globe. The World Meteorological Organization has just launched its High Impact Weather Project, a 10-year, multinational mission. One goal is to create accurate predictions, up to two weeks in advance, for weather that can cause urban floods, severe winter storms, fires, and extreme winds.

“As a consequence of changing climate we foresee an urgent need to extend the forecast concept to cover a much wider range of environmental factors … over a longer range of timescales,” said Paolo Ruti, chief of the organization’s World Weather Research Division.

In the United Kingdom, the Met Office will power up a new supercomputer in September, enabling detailed predictions of disruptive events like flooding, strong winds, and heavy snowfalls. The Danish Meteorological Institute, along with a group of universities and public agencies, is working on medium-range and longer precipitation forecasts for Denmark, Greenland, and the Arctic. The European Center for Medium-Range Weather Forecasts, an independent consortium of 34 European states, continues to hone its powerful Integrated Forecasting System. Other advanced forecasting endeavors include the Japan Meteorological Agency's Global Spectral Model and Canada’s Global Environmental Multi-scale model.

In the U.S., the National Oceanic and Atmospheric Administration (NOAA) is undergoing a major supercomputer upgrade. The increased computing power allowed the weather service to overhaul its outdated Global Forecasting System, which performed well on its maiden runs forecasting the path of the January blizzard that brushed past New York City.

View Gallery
Nor'easter

NASA/Goddard Space Flight Center
Many forecasts predicted the blizzard along the U.S. East Coast in late January would bury New York City, but the storm largely missed the city and slammed into New England instead.


One U.S. project — a collaboration between NOAA, NASA, Scripps, and other agencies to improve forecasts of atmospheric rivers — is underway in California. Atmospheric rivers, which average 250 miles wide and up to 6,000 miles long, are notorious coastal flood-makers in the Americas and Europe, and new studies implicate them in events ranging from rapid ice-melt in Greenland to mammoth snowfalls in Antarctica. Atmospheric rivers are especially important for California, causing more than 80 percent of the state’s serious floods, but also providing up to half of its annual precipitation.

”They fill our reservoirs … they bring these cycles of wet and dry years, they end our droughts, they sustain our wetlands and fisheries, they breach our levees … These things are important,” said Dettinger. And their impact is growing. Dettinger’s analysis of climate models predicts that if greenhouse gas emissions continue their current climb, the number of days atmospheric rivers hit the West Coast each year would rise from today’s average of 25 to more than 65 by the end of the century. Higher temperatures generate more evaporation, he said, and with more water in the atmosphere the storms will become heavier, more intense, and more likely to “stall” and produce floods.

Jason Cordeira, a meteorology professor at Plymouth State University in New Hampshire and lead forecaster on the CalWater 2015 project, combined statistics from an ensemble of 21 weather models to create an atmospheric river Landfall Tool. A pre-test serendipitously coincided with
Maps are being developed that show areas likely to suffer extreme heat and humidity seven to 14 days in the future.
the December atmospheric river — with worthy results.

“For a number of different reasons, the dry run was very, very successful,” said Cordeira, who worked with colleagues from NOAA and Scripps. “We saw the potential for an atmospheric river out nine, 10 days in advance.” The resolution was so clear that forecasters could see where the storm would blow ashore a full week before it landed.

Knowing when and where an atmospheric river will hit, how much moisture it contains, and how fast it will move over land is vital for flood control, transportation, emergency planning, and water supply.

“In a changing climate, it’s really important for societies to be able to anticipate how much water might be available in the future, especially in a state like California,” said Marty Ralph, a research meteorologist at Scripps and co-director of the CalWater project. “We really need to make sure the climate models are handling atmospheric rivers properly.”

Advanced forecasts for other anticipated global warming impacts, such as severe heat waves, are also in the works. For instance, the U.S. National Weather Service’s Climate Prediction Center is developing a “Week-2” outlook with maps showing areas likely to suffer extreme heat and humidity seven to 14 days in the future. The heat outlook is set for release in 2016, and heavy rain and high wind forecasts will be added after that, said Jon Gottschalck, acting chief of the center’s operational predictions branch.

NOAA’s recently launched High-Impact Weather Prediction Project intends to boost its model resolution for a longer view. Resolution, said project manager Tim Schneider, a research meteorologist, depends on

ALSO FROM YALE e360

New Satellite Boosts Research
On Global Rainfall and Climate

NASA Global Precipitation Monitoring satellite
Although it may seem simple, measuring rainfall worldwide has proven to be a difficult job for scientists. But a new satellite is changing that, providing data that could help in understanding whether global rainfall really is increasing as the planet warms.
READ MORE
“how fine you chunk up the earth.” Smaller chunks enable finer resolution — yielding a more fine-grained picture, but also requiring a lot more computing power. “It actually means you need to change the way you do modeling,” said Schneider. “It turns out to be a very big challenge.”

The upshot, say Schneider and others working on extreme weather forecasting, will be to give officials like resource managers and emergency planners the time and information they’ll need for complex decisions, such as whether to let water out of reservoirs when severe rains threaten or shut down city transit systems in advance of snow.

Twenty-first century demographics — with the global population headed toward 10 billion by 2100 and ever-larger numbers of people living along coastlines — make improved extreme weather forecasting imperative, climate scientists say.

“When you combine the impact of these changing demographics with the possibility of a stormier world,” said NOAA’s Schneider, “the effect is pretty staggering, quite honestly.”



POSTED ON 09 Feb 2015 IN Climate Forests Oceans Science & Technology Urbanization 

COMMENTS


''We, as a species, are in the unique situation of not only being able to witness, but also being the cause of our own EXTINCTION.''
Posted by duane carroll on 09 Feb 2015


From the link:

"The intensity, frequency, and duration of North
Atlantic hurricanes, as well as the frequency of
the strongest hurricanes, have all increased
since the early 1980s"

This is very misleading. It is more import what
the global cyclone trends are, not just a single
basin. Individual basins are more erratic
because there is less data available. Global
trends in frequency of cyclones, landfalls, and
total energy (ACE) over all basins show no trend
over the past 50 to 100 years. This information
is readily available and discussed in the IPCC
AR5 report where they cover the lack of evident
trends.

The North Atlantic basin shows no trends in
landfalls over the past 100 years, so choosing
1980 here is a bit suspect.

It should be noted the the same North Atlantic
basin is now in the midst of a record 9 years and
counting without a major Cat3+ hurricane
landfall in the US, by far the longest period ever
recorded. Many dismiss this, but I challenge
those who do to assess what they would
conclude if we had a record number of Cat3+
landfalls over the past 9 years. You can't have it
both ways.
Posted by Tom Scharf on 11 Feb 2015


Excellent points by Muriel Waters.

Posted by LynnAnnRose on 17 Apr 2015


POST A COMMENT

Comments are moderated and will be reviewed before they are posted to ensure they are on topic, relevant, and not abusive. They may be edited for length and clarity. By filling out this form, you give Yale Environment 360 permission to publish this comment.

Name 
Email address 
Comment 
 
Please type the text shown in the graphic.


cheryl katzABOUT THE AUTHOR
Cheryl Katz is a San Francisco Bay Area-based science writer covering energy, environmental health, and climate change. She has reported from Iceland to Africa on issues ranging from geothermal power to flood control. Her articles have appeared in Scientific American, National Geographic.com, and Science News. Previously for e360, she reported on advances in recycling water using desalination and promising new solar energy technologies.
MORE BY THIS AUTHOR

 
 

RELATED ARTICLES


How Climate Change Could Jam
The World's Ocean Circulation

Scientists are closely monitoring a key current in the North Atlantic to see if rising sea temperatures and increased freshwater from melting ice are altering the “ocean conveyor belt” — a vast oceanic stream that plays a major role in the global climate system.
READ MORE

The Dungeness Crab Faces
Uncertain Future on West Coast

The winner of the 2016 Yale Environment 360 Video Contest explores how ocean acidification may be putting at risk a prized crustacean that is vital to the fishing industry and the marine ecosystem on the U.S. Pacific Coast.
READ MORE

The New Green Grid: Utilities
Deploy ‘Virtual Power Plants’

By linking together networks of energy-efficient buildings, solar installations, and batteries, a growing number of companies in the U.S. and Europe are helping utilities reduce energy demand at peak hours and supply targeted areas with renewably generated electricity.
READ MORE

How Growing Sea Plants Can
Help Slow Ocean Acidification

Researchers are finding that kelp, eelgrass, and other vegetation can effectively absorb CO2 and reduce acidity in the ocean. Growing these plants in local waters, scientists say, could help mitigate the damaging impacts of acidification on marine life.
READ MORE

Can Virtual Reality Emerge
As a Tool for Conservation?

New advances in technology are sparking efforts to use virtual reality to help people gain a deeper appreciation of environmental challenges. VR experiences, researchers say, can be especially useful in conveying key issues that are slow to develop, such as climate change and extinction.
READ MORE

 

MORE IN Analysis


How Climate Change Could Jam
The World's Ocean Circulation

by nicola jones
Scientists are closely monitoring a key current in the North Atlantic to see if rising sea temperatures and increased freshwater from melting ice are altering the “ocean conveyor belt” — a vast oceanic stream that plays a major role in the global climate system.
READ MORE

Wildlife Farming: Does It Help
Or Hurt Threatened Species?

by richard conniff
Wildlife farming is being touted as a way to protect endangered species while providing food and boosting incomes in rural areas. But some conservation scientists argue that such practices fail to benefit beleaguered wildlife.
READ MORE

What Would a Global Warming
Increase of 1.5 Degrees Be Like?

by fred pearce
The Paris climate conference set the ambitious goal of finding ways to limit global warming to 1.5 degrees Celsius, rather than the previous threshold of 2 degrees. But what would be the difference between a 1.5 and 2 degree world? And how realistic is such a target?
READ MORE

After Paris, A Move to Rein In
Emissions by Ships and Planes

by fred pearce
As the world moves to slash CO2 emissions, the shipping and aviation sectors have managed to remain on the sidelines. But the pressure is now on these two major polluting industries to start controlling their emissions at last.
READ MORE

Abrupt Sea Level Rise Looms
As Increasingly Realistic Threat

by nicola jones
Ninety-nine percent of the planet's freshwater ice is locked up in the Antarctic and Greenland ice caps. Now, a growing number of studies are raising the possibility that as those ice sheets melt, sea levels could rise by six feet this century, and far higher in the next, flooding many of the world's populated coastal areas.
READ MORE

How Nations Are Chipping
Away at Their Protected Lands

by richard conniff
Winning protected status for key natural areas and habitat has long been seen as the gold standard of conservation. But these gains are increasingly being compromised as governments redraw park boundaries to accommodate mining, logging, and other development.
READ MORE

Can We Reduce CO2 Emissions
And Grow the Global Economy?

by fred pearce
Surprising new statistics show that the world economy is expanding while global carbon emissions remain at the same level. Is it possible that the elusive “decoupling” of emissions and economic growth could be happening?
READ MORE

On Fuel Economy Efforts,
U.S. Faces an Elusive Target

by marc gunther
One of President Obama’s signature achievements on climate has been strict standards aimed at improving auto fuel efficiency to nearly 55 miles per gallon by 2025. But credits and loopholes, coupled with low gas prices, may mean the U.S. will fall well short of this ambitious goal.
READ MORE

New Green Challenge: How to
Grow More Food on Less Land

by richard conniff
If the world is to have another Green Revolution to feed its soaring population, it must be far more sustainable than the first one. That means finding ways to boost yields with less fertilizer and rethinking the way food is distributed.
READ MORE

How Forest Loss Is Leading
To a Rise in Human Disease

by jim robbins
A growing body of scientific evidence shows that the felling of tropical forests creates optimal conditions for the spread of mosquito-borne scourges, including malaria and dengue. Primates and other animals are also spreading disease from cleared forests to people.
READ MORE


e360 digest
Yale
Yale Environment 360 is
a publication of the
Yale School of Forestry
& Environmental Studies
.

SEARCH e360



Donate to Yale Environment 360
Yale Environment 360 Newsletter


CONNECT


ABOUT

About e360
Contact
Submission Guidelines
Reprints

E360 en Español

Universia partnership
Yale Environment 360 articles are now available in Spanish and Portuguese on Universia, the online educational network.
Visit the site.


DEPARTMENTS

Opinion
Reports
Analysis
Interviews
Forums
e360 Digest
Podcasts
Video Reports

TOPICS

Biodiversity
Business & Innovation
Climate
Energy
Forests
Oceans
Policy & Politics
Pollution & Health
Science & Technology
Sustainability
Urbanization
Water

REGIONS

Antarctica and the Arctic
Africa
Asia
Australia
Central & South America
Europe
Middle East
North America

e360 VIDEO

“video
Tribal people and ranchers join together to stop a project that would haul coal across their Montana land.
Watch the video.

e360 MOBILE

Mobile
The latest
from Yale
Environment 360
is now available for mobile devices at e360.yale.edu/mobile.

e360 PHOTO ESSAY

“Alaska
An aerial view of why Europe’s per capita carbon emissions are less than 50 percent of those in the U.S.
View the photos.

e360 VIDEO

“Ugandan
Ugandan scientists monitor the impact of climate change on one of Africa’s most diverse forests and its extraordinary wildlife.
Learn more.

e360 VIDEO

Food waste
An e360 video series looks at the staggering amount of food wasted in the U.S. – a problem with major human and environmental costs.
Watch the video.

e360 VIDEO

Colorado wildfires
An e360 video goes onto the front lines with Colorado firefighters confronting deadly blazes fueled by a hotter, drier climate.
Watch the video.

e360 SPECIAL REPORT

“Tainted
A three-part series Tainted Harvest looks at the soil pollution crisis in China, the threat it poses to the food supply, and the complexity of any cleanup.
Read the series.

OF INTEREST



Yale