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NCAR|UCAR hurricane experts available to explain storm behavior, potential impacts

BOULDER, Colo. — As Hurricane Harvey takes aim at Texas, scientists at the National Center for Atmospheric Research (NCAR) and its managing organization, the University Corporation for Atmospheric Research (UCAR), are closely watching the storm and testing high-resolution computer models.Hurricane experts are available to explain issues such as:How we can better predict the possible impacts of hurricanes, including wind damage, flooding, and subsequent spread of disease-bearing mosquitoes;How people respond to hurricane forecast and warning messages and how risk communication can be improvedWhether climate change is affecting hurricanes and what we can expect in the future;The importance of improving weather models to safeguard life and property.Antonio Busalacchi, UCAR president (please contact David Hosansky for interview requests)An expert on ocean-atmosphere interactions, Busalacchi has testified before Congress on the importance of improving the nation's weather forecasting capabilities to better protect life and property, bolster the economy, and strengthen national security. He has firsthand experience with storms along the Gulf Coast as a part-time New Orleans resident, and he is a member of the Gulf Research Program Advisory Board of the National Academy of Sciences.Christopher Davis, director, NCAR Mesoscale and Microscale Meteorology Laboratory, cdavis@ucar.edu, 303-497-8990Davis studies the weather systems that lead to hurricanes and other heavy rainfall events. His expertise includes hurricane prediction and how computer models can be improved to better forecast storms. His NCAR weather lab is running experimental computer simulations of Hurricane Harvey.James Done, NCAR scientist, done@ucar.edu, 303-497-8209Done led development of the innovative Cyclone Damage Potential (CDP) index, which quantifies a hurricane's ability to cause destruction, using a scale of 1 to 10. It can also be used to examine the damage potential for cyclones in the future as the climate warms.David Gochis, NCAR scientist, gochis@ucar.edu, 303-497-2809An expert in hydrometeorology, Gochis studies the causes of floods and how to better predict them. He helped develop pioneering software that is at the core of the National Water Model. The National Oceanic and Atmospheric Administration Office of Water Prediction uses this model to provide a continuous picture of all the waterways in the contiguous United States and alert officials to potentially dangerous floods.Matthew Kelsch, UCAR hydrometeorologist, kelsch@ucar.edu, 303-497-8309Kelsch has studied some of the biggest U.S. flood events connected to hurricanes and tropical storms. He trains scientists and forecasters from around the world on emerging hydrology and weather topics.Rebecca Morse, NCAR scientist, morss@ucar.edu, 303-497-8172Morss studies the predictability of hurricane-related hazards, including storm surge and inland flooding, and hurricane and flood risk communication and evauation decision making.Kevin Trenberth, NCAR senior scientist, trenbert@ucar.edu, 303-497-1318Trenberth is an expert on the global climate system. He has been in the forefront of scientists examining the potential influence of climate change on the intensity of tropical storms and hurricanes and the increased widespread flooding that they cause.Jeff Weber, UCAR meteorologist, jweber@ucar.edu, 303-497-8676As an expert on hurricanes and severe weather in general, Weber closely monitors the behavior of individual storms and the larger atmospheric and oceanic conditions that influence them.

The Master Plan of the Shagaya Renewable Energy Park in Kuwait - Friday

Note new date: Friday, August 18

The Master Plan of the Shagaya Renewable Energy Park in Kuwait
Yousuf Al-Abdulla | Kuwait Institute for Scientific Research, Kuwait City, Kuwait

A Beginners Introduction to the Analog Ensemble Technique

A Beginners Introduction to the Analog Ensemble Technique

LAURA CLEMENTE-HARDING | THE PENNSYLVANIA STATE UNIVERSITY, UNIVERSITY PARK, PA, AND THE ENGINEER RESEARCH AND DEVELOPMENT CENTER, ALEXANDRIA, VA

Warmer temperatures cause decline in key runoff measure

BOULDER, Colo. — Since the mid-1980s, the percentage of precipitation that becomes streamflow in the Upper Rio Grande watershed has fallen more steeply than at any point in at least 445 years, according to a new study led by the National Center for Atmospheric Research (NCAR).While this decline was driven in part by the transition from an unusually wet period to an unusually dry period, rising temperatures deepened the trend, the researchers said.The study paints a detailed picture of how temperature has affected the runoff ratio — the amount of snow and rain that actually makes it into the river — over time, and the findings could help improve water supply forecasts for the Rio Grande, which is a source of water for an estimated 5 million people.The study results also suggest that runoff ratios in the Upper Rio Grande and other neighboring snow-fed watersheds, such as the Colorado River Basin, could decline further as the climate continues to warm.Sandhill cranes in the San Luis Valley of Colorado. The mountains ringing the valley form the headwaters of the Rio Grande River, which flows south into New Mexico and along the border between Texas and Mexico. (Photo courtesy of the National Park Service.)"The most important variable for predicting streamflow is how much it has rained or snowed," said NCAR scientist Flavio Lehner, lead author of the study. "But when we looked back hundreds of years, we found that temperature has also had an important influence  — which is not currently factored into water supply forecasts. We believe that incorporating temperature in future forecasts will increase their accuracy, not only in general but also in the face of climate change."The study, published in the journal Geophysical Research Letters, was funded by the Bureau of Reclamation, Army Corps of Engineers, National Oceanic and Atmospheric Administration (NOAA), and National Science Foundation, which is NCAR's sponsor.Co-authors of the paper are Eugene Wahl, of NOAA; Andrew Wood, of NCAR; and Douglas Blatchford and Dagmar Llewellyn, both of the Bureau of Reclamation.Over-predicting water supplyBorn in the Rocky Mountains of southern Colorado, the Rio Grande cuts south across New Mexico before hooking east and forming the border between Texas and Mexico. Snow piles up on the peaks surrounding the headwaters throughout the winter, and in spring the snowpack begins to melt and feed the river.The resulting streamflow is used both by farmers and cities, including Albuquerque, New Mexico, and El Paso, Texas, and water users depend on the annual water supply forecasts to determine who gets how much of the river. The forecast is also used to determine whether additional water needs to be imported from the San Juan River, on the other side of the Continental Divide, or pumped from groundwater.Current operational streamflow forecasts depend on estimates of the amount of snow and rain that have fallen in the basin, and they assume that a particular amount of precipitation and snowpack will always yield a particular amount of streamflow.In recent years, those forecasts have tended to over-predict how much water will be available, leading to over-allocation of the river. In an effort to understand this changing dynamic, Lehner and his colleagues investigated how the relationship between precipitation and streamflow, known as the runoff ratio, has evolved over time.Precipitation vs. streamflow: Tree rings tell a new storyThe scientists used tree ring-derived streamflow data from outside of the Upper Rio Grande basin to reconstruct estimates of precipitation within the watershed stretching back to 1571. Then they combined this information with a separate streamflow reconstruction within the basin for the same period. Because these two reconstructions were independent, it allowed the research team to also estimate runoff ratio for each year: the higher the ratio, the greater the share of precipitation that was actually converted into streamflow."For the first time, we were able to take these two quantities and use them to reconstruct runoff ratios over the past 445 years," Wahl said.They found that the runoff ratio varies significantly from year to year and even decade to decade. The biggest factor associated with this variation was precipitation. When it snows less over the mountains in the headwaters of the Rio Grande, not only is less water available to become streamflow, but the runoff ratio also decreases. In other words, a smaller percentage of the snowpack becomes streamflow during drier years.But the scientists also found that another factor affected the runoff ratio: temperature. Over the last few centuries, the runoff ratio was reduced when temperatures were warmer. And the influence of temperature strengthened during drier years: When the snowpack was shallow, warm temperatures reduced the runoff ratio more than when the snowpack was deep, further exacerbating drought conditions. The low runoff ratios seen in dry years were two and a half to three times more likely when temperatures were also warmer."The effect of temperature on runoff ratio is relatively small compared to precipitation," Lehner said. "But because its greatest impact is when conditions are dry, a warmer year can make an already bad situation much worse."A number of factors may explain the influence of temperature on runoff ratio. When it's warmer, plants take up more water from the soil and more water can evaporate directly into the air. Additionally, warmer temperatures can lead snow to melt earlier in the season, when the days are shorter and the angle of the sun is lower. This causes the snow to melt more slowly, allowing the meltwater to linger in the soil and giving plants added opportunity to use it.The extensive reconstruction of historical runoff ratio in the Upper Rio Grande also revealed that the decline in runoff ratio over the last three decades is unprecedented in the historical record. The 1980s were an unusually wet period for the Upper Rio Grande, while the 2000s and 2010s have been unusually dry. Pair that with an increase in temperatures over the same period, and the decline in runoff ratio between 1986 and 2015 was unlike any other stretch of that length in the last 445 years.The graph shows changes to runoff ratio in the Upper Rio Grande over time. (Image courtesy Flavio Lehner, NCAR.) Upgrading the old approachesThis new understanding of how temperature influences runoff ratio could help improve water supply forecasts, which do not currently consider whether the upcoming months are expected to be hotter or cooler than average. The authors are now assessing the value of incorporating seasonal temperature forecasts into water supply forecasts to account for these temperature influences. The study complements a multi-year NCAR project funded by the Bureau of Reclamation and the Army Corps of Engineers that is evaluating prospects for enhancing seasonal streamflow forecasts for reservoir management.“Forecast users and stakeholders are increasingly raising questions about the reliability of forecasting techniques if climate is changing our hydrology," said Wood, who led the effort. "This study helps us think about ways to upgrade one of our oldest approaches — statistical water supply forecasting — to respond to recent trends in temperature. Our current challenge is to find ways to make sure the lessons of this work can benefit operational streamflow forecasts.” Because the existing forecasting models were calibrated on conditions in the late 1980s and 1990s, it's not surprising that they over-predicted streamflow in the drier period since 2000, Lehner said."These statistical models often assume that the climate is stable," Lehner said. "It's an assumption that sometimes works, but statistical forecasting techniques will struggle with any strong changes in hydroclimatology from decade to decade, such as the one we have just experienced."Lehner is a Postdoc Applying Climate Expertise (PACE) fellow, which is part of the Cooperative Programs for the Advancement of Earth System Science (CPAESS). CPAESS is a community program of the University Corporation for Atmospheric Research (UCAR).About the articleTitle: Assessing recent declines in Upper Rio Grande River runoff efficiency from a paleoclimate perspectiveAuthors: Flavio Lehner, Eugene R. Wahl, Andrew W. Wood, Douglas B. Blatchford, and Dagmar LlewellynJournal: Geophysical Research Letters, DOI: 10.1002/2017GL073253Writer:Laura Snider, Senior Science Writer and Public Information Officer

NCAR to develop advanced wind and solar energy forecasting system for Kuwait

BOULDER, Colo. — Expanding its work in renewable energy, the National Center for Atmospheric Research (NCAR) is launching a three-year project to develop specialized forecasts for a major wind and solar energy facility in Kuwait."We're putting our expertise and technology to work around the world," said NCAR Senior Scientist Sue Ellen Haupt, the principal investigator on the project. "This landmark project meets our mission of science in service to society."The $5.1 million project will focus on developing a system to provide detailed forecasts of wind and solar irradiance at Kuwait's planned 2-gigawatt Shagaya renewable energy plant. After NCAR develops the system, the technology will be transferred to the Kuwait Institute for Scientific Research (KISR) for day-to-day operations.Salem Al-Hajraf of KISR and Antonio J. Busalacchi of UCAR shake hands over an agreement to create a renewable energy forecasting system. Behind them are NCAR scientists (left to right): Gerry Wiener, Branko Kosovic, Sue Ellen Haupt, and William Mahoney. (©UCAR. Photo by Carlye Calvin. This image is freely available for media & nonprofit use.)The forecasts will help Kuwait reach its goal of generating 15 percent of its energy from renewable sources by 2030. With the ability to anticipate the amount of electricity that sun and wind will produce hours to days in advance, energy operators will be able to power up or down traditional plants as needed to meet demand."This technology will provide us with important benefits," said Salem Al-Hajraf, manager of KISR's Renewable Energy Program. "We are providing green energy to the grid using abundant sources of energy, which are sun and wind."Reducing renewable energy costsWhen electric utilities integrate power from intermittent sources such as wind or solar into the grid, they temporarily reduce or shut off traditional sources such as oil or natural gas. But if weather conditions fail to come together as expected, the utility may not be able to power up traditional plants in time to meet their customer needs.To help utility managers anticipate renewable wind energy more reliably, NCAR has designed and is constantly improving a wind energy prediction system for Xcel Energy that has saved tens of millions of dollars for the utility’s customers in Colorado and nearby states. The specialized system relies on a suite of tools, including highly detailed observations of atmospheric conditions, advanced computer modeling, and artificial intelligence techniques that enable Xcel Energy to issue high-resolution forecasts for wind farm sites.With funding from the U.S. Department of Energy, NCAR has also led a national team of scientists who have developed a cutting-edge forecasting system with the potential to save the solar energy industry hundreds of millions of dollars in the United States alone through improved forecasts. The new Sun4CastTM system, unveiled last year, greatly improves predictions of clouds and other atmospheric conditions that influence the amount of energy generated by solar arrays.Adapting to new conditionsIn Kuwait, the NCAR team will build on these technologies to develop both wind and solar energy forecasts. The scientists will customize the system to predict dust storms that can blot out sunlight and damage wind turbines. They will also incorporate the influence of nearby mountain ranges and the Persian Gulf on local weather patterns."This is a great opportunity to do research into dust and other particulates, which we haven't previously needed to focus on to this extent for wind and solar energy prediction," Haupt said. "This kind of work will pay multiple dividends for energy forecasting as well as better understanding and predicting of weather in certain desert environments."Haupt and her team will collaborate with researchers at Pennsylvania State University and Solar Consulting Services in Florida, as well as with KISR."This is an exciting international partnership that will both generate significant economic benefits and advance our understanding of the atmosphere," said Antonio J. Busalacchi, president of the University Corporation for Atmospheric Research. "In addition to reducing energy costs for our partners in Kuwait, the knowledge that we gain will help us further improve weather prediction skills here in the United States."The University Corporation for Atmospheric Research is a nonprofit consortium of 110 North American colleges and universities that manages the National Center for Atmospheric Research under sponsorship by the National Science Foundation.KISR leads and partners internationally to develop, deploy, and exploit the best science, technology, knowledge, and innovation for public and private sector clients, for the benefit of Kuwait and others facing similar challenges and opportunities. Sun4Cast is a trademark of the University Corporation for Atmospheric Research.

Drones need aviation forecasts, too

UAS Weather ForumWhat: An opportunity for stakeholders from the UAS community -- including manufacturers, operators, regulators, and researchers -- to come together to discuss weather effects on drones and the support needed to mitigate those impacts.When: 9 a.m. - 12 p.m., Monday, May 8, 2017Where: XPONENTIAL, Kay Bailey Hutchison Convention Center, Dallas Click here for more information.April 13, 2017 | The possible future uses for drones are spectacularly diverse. Unmanned aircraft systems (UAS) could make door-to-door deliveries, search for a lost hiker, survey agricultural crops, inspect infrastructure, or collect scientific data from difficult-to-reach places, among other things. Already Amazon is experimenting with drone delivery of packages, for example, and BNSF Railway is testing the use of drones to inspect hundreds of miles of railroad tracks.Yet the ultimate success of efforts like these may hinge on a good weather forecast. The National Center for Atmospheric Research (NCAR), long a trusted provider of critical weather information to the aviation industry, is beginning to lend its expertise to the UAS community as well.Staff in NCAR's Research Applications Laboratory are already working with NASA to provide low-level turbulence forecasts for NASA's project to create a UAS Traffic Management (UTM) system, which would be similar to the air traffic control system for crewed airplanes. And in May, the NCAR team is hosting a UAS Weather Forum in Dallas. The forum will be co-located with XPONENTIAL, a conference on "all things unmanned" that is organized by the Association of Unmanned Vehicle Systems International."As the aircraft get smaller and smaller, the challenges of providing the needed weather information increase," said NCAR scientist Matthias Steiner, deputy director of RAL's Aviation Applications Program. "These small UAS's are more sensitive to winds, temperature, turbulence, precipitation — essentially the full range of weather — than larger planes flying at higher altitudes."NASA engineers prepare to launch a remotely piloted aircraft during practice runs for an Unmanned Aircraft Systems Traffic Management test. (Image courtesy NASA.)Weather impacts on dronesDrones, at least the small ones allowed under current Federal Aviation Administration rules, fly in the lowest few hundred feet of the atmosphere, where weather can be highly dynamic and less predictable.This layer of the atmosphere is heavily affected by land surface and topography. Consider, for example, wind as it blows through a city. The buildings force the wind to speed through "urban canyons" and swirl into tight eddies behind structures. Uneven heating — the sunny side of the street warming more than the shady side, for example — can create circulating downdrafts and updrafts.Piloting a drone through a built-up area could be tricky without a detailed understanding of the local atmospheric circulation patterns. And even with that information, it's important to understand how different drones will be affected. The tinier and lighter the drone, the more vulnerable it is to the vagaries of the weather, just as a small Cessna is more vulnerable to turbulence than a giant 747. And the type of drone, such as a fixed wing or a quadcopter, matters as well because each has a different ability to respond.The concern is not just crashing on the ground; severe weather conditions could also lead to a collision in the sky. NASA's UTM project is exploring the possibility of managing a high volume of drones by essentially assigning individual UAS's to a lane of airspace. But weather will affect the ability of a drone to stay in its lane. An abrupt updraft, for instance, could force a drone that is supposed to fly at a lower altitude into the higher-altitude lane assigned to another UAS (or a crewed aircraft in mixed airspace), increasing the possibility of a collision between the two.Weather can have less obvious impacts on drone operation as well. Extremely cold weather, headwinds, or turbulence that requires a lot of flight control adjustments could drain the aircraft's battery more quickly, reducing its range and, potentially, its ability to return home. Facilitating a community dialogueThese kinds of weather challenges would likely not surprise a seasoned aviator. But many of the organizations interested in using drones today come to the UAS community from the technology side, not the aviation side, and may lack a full understanding of the impacts that atmospheric conditions can have on flight.This is where NCAR has expertise to offer. For decades, NCAR has been providing the aviation industry with the tools they need to increase flight safety, including wind shear alerts, turbulence forecasts, and information on inflight icing potential.In an effort to stay on top of the latest weather challenges facing the aviation industry, NCAR launched the Friends and Partners in Aviation Weather Forum in 1997. The meeting, now held twice yearly, is an opportunity for stakeholders from the operational, regulatory, and research sectors to come together."We created these meetings as a means of fostering dialogue," Steiner said. "We want to know: 'What are your operational sensitivities? How can we help you?' Now we are emulating these forums with the UAS community. "The UAS Weather Forum at the XSPONENTIAL conference on May 8 is the first effort at starting a similar meeting—and fostering the dialogue needed to advance drone safety, even in the face of challenging weather conditions."We want drone operators to know NCAR is a partner that can help them address their weather impacts," Steiner said.Writer/contact: Laura Snider, Senior Science Writer and Public Information Officer

Congressional briefing on wildland fires

WASHINGTON, D.C. — Scientists and fire experts are making landmark progress in developing new tools to improve the management and prediction of wildland fires, a panel of experts said at a congressional briefing today. The developments offer the potential of better protecting vulnerable residents and property from these extreme events, as well as reducing their costs. The briefing, sponsored by the University Corporation for Atmospheric Research (UCAR), highlighted the development of new observing tools and advanced computer models to better understand wildland fires. "We're at a turning point where new technologies and advances in basic research are enabling us to tackle a major real-world problem," said UCAR President Antonio J. Busalacchi. "Federal and state agencies, firefighters, and scientists are all working together to develop a new generation of tools that will keep firefighters safer, reduce the costs of these massive conflagrations, and better safeguard lives and property."Bureau of Land Management firefighter near Burns, Oregon, in September 2011. (Photo by Dave Toney, BLM Oregon.)UCAR is a consortium of 110 universities that manages the National Center for Atmospheric Research (NCAR) on behalf of the National Science Foundation. NCAR's wildland fire research includes working with Colorado on an advanced prediction system.Toll of wildland fires The costs of forest, grass, and other types of wildland fires are increasing dramatically. In 2016 alone, more than 67,000 wildfires consumed 5.5 million acres across the nation. The U.S. Forest Service spends more than $2.5 billion annually on fire management, an increase of more than 60 percent over the last decade. The total losses can run many times higher: Last year's Chimney Tops 2 fire in Gatlinburg, Tennessee, left 14 people dead and destroyed more than 2,400 structures at a cost of $500 million. "The money spent by the federal government on suppressing the fires is only a fraction of the overall costs, such as the destruction of houses and other property," said Michael Gollner, assistant professor at the University of Maryland's Department of Fire Protection Engineering. "There are more large-scale fires than there used to be, and those are the most dangerous blazes that are particularly expensive and destructive." Donald Falk, assistant professor of the University of Arizona's School of Natural Resources and the Environment, warned that decades of fire suppression coupled with drier and warmer temperatures in some regions will lead to longer fire seasons and more major fires. "The problem is not going away," he said. "It's going to get bigger, and we're going to have to live with it without breaking the bank." Wildland fires are extremely difficult to predict because they are influenced by local topography and vegetation, as well as by atmospheric conditions that, in turn, are affected by a blaze's heat and smoke. To better anticipate fire risk as well as predict a fire once it has started, scientists are harnessing new technologies. These include specialized satellite instruments and unmanned aerial vehicles to observe the blazes, as well as specialized computer models that incorporate weather-fire interactions, the density and condition of vegetation, landscape features such as elevation and topography, and the physics of fires. The researchers are working with federal and state agencies, emergency managers, and firefighters to adapt the new capabilities for real-time decision support. "Practitioners and scientists are bringing their expertise and knowledge to the table in order to create new evolutions of technology that will result in safer and more effective firefighting, enhance how we predict events and their potential impacts, and better plan for ways to prevent those wildfires we consider harmful," said Todd Richardson, state fire management officer of the Bureau of Land Management's Colorado office. "Having better guidance prior to planning your fire operations can provide critical information to the tactical operations and fire management," said William Mahoney, interim director of NCAR's Research Applications Laboratory. "Taking advantage of these important data sources and integrating these research areas provides tremendous opportunities to advance wildland fire management." The event is the latest in a series of UCAR congressional briefings that draw on expertise from the university consortium and public-private partnerships to provide insights into critical topics in the Earth system sciences. Past briefings have focused on predicting space weather, aviation weather safety, the state of the Arctic, hurricane prediction, potential impacts of El Niño, and new advances in water forecasting.

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