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Research Applications Program
Executive Summary



The central mission of the Research Applications Program is consonant with that of NCAR and UCAR: To develop and transfer knowledge and technology to the public and private sectors. The motivation for this is embodied in what Walter O. Roberts, the first Director of NCAR, termed “science in service to society.”

Through a program of directed research aimed at solving practical problems, RAP contributes to the depth of fundamental and practical understanding in atmospheric science and develops new sources of support for such research. Through a program of technology transfer, RAP expands the reach of atmospheric science into weather-sensitive human endeavors that are not currently making practical use of weather information or are using such information in naïve or inefficient ways. Educating potential users of weather information in the “art of the possible” is an important element in securing new investments in research and development.


Over the past two decades RAP has developed a large reservoir of capabilities in basic science, applied-research methods, software engineering, technology transfer, and program management. Those capabilities have been brought to bear on problems in a variety of application areas, demonstrating the potential of advanced weather information to benefit society.




Aviation Applications

In collaboration with FAA and NASA sponsors, national laboratories and universities, RAP works to improve the detection, measurement, and forecasting of hazardous weather and to transfer information, expertise and new technologies to those working to improve the safety and efficiency of the nation’s airspace. These efforts have established NCAR as a leader, both nationally and internationally, in aviation weather research and development

In-Flight Icing

Research within the In-flight Icing program is focused on achieving better characterization of cloud and weather conditions associated with icing environments. In 2004 improvements to the MM5 and WRF models, including microphysical parameterizations to more accurately forecast cloud liquid, drizzle and rain, were made in collaboration with NOAA/FSL and NCEP. Development of an operational liquid water path retrieval algorithm based on satellite-based passive microwave sensors was also accomplished. A new NASA-sponsored effort was initiated to increase and optimize the use of its satellite datasets in products developed for the FAA. Early efforts are focused on assessing whether satellite data can improve the performance of the Current Icing Potential algorithm.


RAP scientists led the effort to develop and conduct initial testing of the SPolKa radar system which combines a Ka-band (0.86 cm) radar with ATD’s SPol S-band (10 cm.) weather radar. This work was funded by FAA and NSF and conducted in conjunction with ATD. RAP also planned and executed the Winter Icing and Storms Project 2004 field program, deploying research radars and radiometers in the Boulder area to evaluate remote sensing techniques for characterizing cloud icing conditions. The transfer of new aviation weather products to the user community continued with the successful transfer of the Current Icing Potential product for Alaska and an icing severity algorithm. Both have been approved for use as experimental products by the National Weather Service.


Snowfall and Freezing Precipitation

RAP continued to work to improve the detection, measurement, forecasting, and reporting of frozen precipitation, as well as to develop new data analysis, product synthesis, and decision support tools. While the focus remains largely on aviation applications, it has become clear that this work could have significant benefit in the surface transportation domain as well.

Scientists in the FAA-funded Winter Weather Program demonstrated this year that major jet engine damage—recorded in three separate incidents in Denver and Oslo, Norway—was due to heavy freezing drizzle. Official weather observations had reported only light snow and mist or light drizzle, and thus proper precautions were not taken to protect the planes as they prepared for departure. RAP scientists conducted a training class for United Airlines pilots on lessons learned from these cases and will publish their results in a journal article accepted for publication in 2005.

Several technologies developed at RAP were successfully transferred to the private and public sectors this year. The Hot-Plate precipitation gauge developed by RAP and the Desert Research Institute has been transferred to Yankee Environmental Systems for production and marketing. A commercial prototype of the Weather Support to Deicing Decision Makers (WSDDM) system is now in full operational use at Denver International Airport and serves as a testbed for developing new products as well as obtaining user feedback. A new company, WSDM Technologies, Inc., has been formed to market, build, operate and maintain WSDDM systems at aviation facilities in the future.

Convective Weather

The Convective Weather Program’s overarching goal is an improved ability to predict the location, intensity and organization of convective storms in the 0-6 hour forecast period. With NSF funding, RAP scientists conducted fundamental research into convective storm initiation and evolution processes and worked to improve microphysical parameterizations of precipitation.

The development of operational forecast systems continued with support from the FAA and the U.S. Army Test and Evaluation Command. The Auto-Nowcaster (ANC), an automated, regional-scale forecast system that produces high-resolution 0-2 hour forecasts, was demonstrated for a third year as part of the FAA’s Regional Convective Weather Forecast (RCWF) Program in the Chicago area. The boundary layer version of the Variational Doppler Radar Analysis System (VDRAS) was also demonstrated at RCWF, assimilating data from five WSR-88D radars. An explicit storm version of VDRAS moved from research mode to operational status in 2004 and was run in real-time over the RCWF domain during the summer.

A second forecast system developed at RAP, the National Convective Weather Forecast product (NCWF) was substantially improved and transferred to the National Weather Service for testing. The new product, NCWF-2, provides better quality control and use of RUC model winds, incorporates a large-scale trending algorithm that captures dissipation of storms within a region rather than simply tracking individual storms, and establishes 1 and 2 hour probabilities which allows for quantification of uncertainty inherent in forecasts.


Fundamental research aimed at characterizing different kinds of turbulence and the mechanisms that generate it expanded substantially in 2004. Funding from FAA and NASA supported a number of high-resolution numerical simulations of cases involving encounters with turbulence induced by mountain waves, island wakes, convection, and the urban environment.

Progress continued to be made in detecting atmospheric turbulence using both in-situ measurements from on-board commercial aircraft and, increasingly, from information provided by airborne and ground-based Doppler radars. This year RAP scientists refined and tested the NCAR Turbulence Detection Algorithm, a new algorithm designed for use on the nation’s NEXRAD and TDWR radars. Initial verification efforts show promise for the algorithm’s ability to detect moderate-or-greater turbulence before an aircraft encounters it. A new software package that provides automated scoring tools to evaluate airborne turbulence detection was also completed and delivered to NASA and will become part of a toolset for researchers and radar manufacturers in tuning their detection systems.

The effort to improve short-term forecasting of turbulence continued with improvements made to the Graphical Turbulence Guidance (GTG) product which was developed at RAP and is run operationally by the NWS. In 2004 work focused on extending the capability of GTG to detect clear air turbulence below 20,000 ft MSL and to incorporate a new capability to forecast convectively-induced turbulence.

In the technology transfer arena, the operational prototype of the Juneau Airport Wind System was successfully evaluated and installed for testing at the Juneau, Alaska, Airport.

Remote Sensing

Funding from the FAA’s Advanced Weather Radar Techniques program supported RAP scientists’ participation in the Winter Icing and Storm Project 2004. A two-dimensional video disdrometer and the NCAR S-Pol radar were fielded in an on-going effort to develop algorithms for classifying hydrometeor types, quantifying winter precipitation, and improving the parameterization of winter storm microphysics in numerical forecast models. Preliminary studies of the WISP datasets indicate that radar can detect subtle changes in particle habits and that it should be possible to estimate the governing parameters of hydrometeor distributions. Evaluation of the NCAR hail detection algorithm concluded in 2004 with a final report that indicated that polarimetric radar has important advantages for specifying the location of hail and perhaps its size. Testing of the NCAR freezing level algorithm was also successfully completed in 2004; results of this work will be published in two journal articles in 2005.

Ceiling and Visibility

Adverse ceiling and visibility (C&V) conditions are a contributing factor in over 35% of all weather-related accidents in the US civil aviation sector and a major cause of flight delays nationwide. RAP scientists worked throughout 2004 to better understand C&V conditions and to develop national and terminal-area forecast systems. Progress is being made in forecasting C&V through the development of an automated meteorological database to improve forecast integration efforts; use of Knowledge Discovery in Databases techniques for improved analysis and translation of model results; and new data mining techniques to create rulesets for forecasting C&V at specific sites. RAP scientists also studied the feasibility of making short-term visibility forecasts using radar data calibrated to a surface visibility sensor.

RAP staff continued to work with colleagues from MIT/Lincoln Laboratory to develop and display more accurate forecasts of operationally significant changes in ceiling height and/or visibility near major airports in the Northeastern US 2004 marked the successful completion of the development of a San Francisco Marine Stratus Forecaster Display which provides accurate forecasts of the time that fog will clear in the approach to the San Francisco Airport. This system has now been transferred to the NWS and is now running operationally.

Oceanic Weather

The Oceanic Weather (OW) program worked to improve the forecasts of aviation hazards in data-sparse oceanic regions of the world. In 2004 the OW team developed new methods for diagnosing convection and turbulence over the ocean, the first step in meeting the goal of a reliable 0-2 hour forecast of these phenomena. Development of a new volcanic ash product advanced with the creation of a new means of interpreting and graphically displaying text-based volcanic ash warnings issued for aviation by countries around the world. The decoding of these messages and consistent presentation of them on an automated web-based world display makes it possible for the first time to see at a glance where advisories exist for volcanic ash.

Numerical Weather Prediction Applications

Numerical weather prediction in RAP involves developing, testing and implementing operational forecasting systems throughout the world. Models are used for public weather forecasting, for defense and homeland security applications, for the prediction of aviation-related hazards such as icing and turbulence, and for the support of field programs. In addition, weather models are being coupled with other models that compute cloud ceiling and visibility, transport and dispersion, stream flow and sound propagation.

A number of new developments have become apparent: Models used for research and operations have had progressively greater horizontal resolution; urban modeling, using .5-1.0 km grid increments, has become an important new focus. To resolve at the building level, collaboration with others proficient in the use of computational fluid dynamics models has become critical. Another important change has been a methodical migration from MM5 to WRF in RAP’s operational modeling systems. New capabilities developed at RAP for WRF, such as the Newtonian relaxation-data assimilation code, are being transitioned to the community version of WRF. Work also continues to develop next-generation land-surface physics for WRF, as well as a high-resolution land data-assimilation system (link to LSM).

Department of Defense/Homeland Security Programs

RAP continued to refine the four-dimensional weather systems (4DWX) currently deployed at six US Army test ranges. An ensemble prediction system was tested, improved verification methods developed, MM5 and WRF forecasts inter-compared, advanced data assimilation concepts developed, and new bias-correction procedures created. The 4DWX system was also adapted for use over metropolitan areas this year, and new capabilities were tested in a field program at the Pentagon in April-May, 2004.

New Homeland Security applications in 2004 included:

  • Production of high-resolution analyses and forecasts of winds to aid in calculating the transport and dispersion of hazardous materials released into the atmosphere.

  • Use of Global Meteorology on Demand, a tool developed at RAP which allows a non-meteorologist to launch MM5 anywhere in the world, in support of counter-terrorist operations at the Athens Olympics.

  • Adaptation of the Variational Doppler Radar Assimilation System to assimilate Doppler lidar radial-wind data (VLAS). The high-resolution gridded wind fields that result are used in transport and dispersion models.

  • Development of an operational atmospheric-hazard assessment and prediction system to protect the Pentagon and its 25,000+ inhabitants. This RAP-led effort includes collaboration with ATD, University of Colorado, NOAA, and DARPA.

Land Surface Modeling

In a highly collaborative effort with MMM, RAP scientists worked to understand the complex interactions between the land-surface and the atmosphere and to integrate this knowledge into numerical mesoscale weather prediction and regional climate models. Accomplishments this year included:

  • Development and implementation of the unified Noah land-surface modeling (LSM) system in the WRF model V2.0, released in May 2004.

  • Development of a High-Resolution Data Assimilation System (HRLDAS) to support application of high-resolution numerical weather prediction models. HRLDAS uses observed precipitation, solar radiation derived from satellite data, and surface wind and temperature data to force a land-surface model to simulate the evolution of soil moisture.

  • Coupling a single-layer urban canopy model with the Noah LSM to simulate urban heat island effects. This work is important in representing the effect of the urban environment on local and regional weather within NWP models.

Geographical Information Systems

The NSF-funded GIS Initiative aims to promote and support the use of GIs as an analysis and infrastructure tool in atmospheric research. The program, a collaborative effort with ESIG, focused this year on providing support for the Community Climate System Model effort. Model results from CCSM were converted to GIs-compatible formats for distribution in 2005 to the GIs user community via a public website. This effort will put detailed climate change information in the hands of decision-makers, educators and researchers.

Hydrometeorological Applications

RAP's water resource-related activities expanded substantially in 2004 as new programs, sponsors, and collaborations were established. Working with colleagues across NCAR, RAP scientists engaged in NSF-sponsored research in the “Water Cycle Across Scales” initiative. This effort is focused on achieving better understanding of water cycle processes in order to improve convective, land surface and microphysical parameterizations in weather and climate models. Water cycle efforts at RAP were focused in three areas: Analysis of data from the 2001 IMPROVE II field program in Oregon to improve cloud microphysical parameterizations; analysis of IHOP data to better parameterize convection within models; and studies of land-atmosphere interactions and the role of land surface processes in triggering convection to improve land surface models.

In other research endeavors, NOAA funding supported RAP’s participation in the North American Monsoon Experiment. In collaboration with scientists from the University of Arizona and Mexican institutions, progress was made in diagnosing and modeling key aspects of rainfall climatology in western Mexico and their relationship to regional streamflow. RAP also participated in an NSF-sponsored effort to define a vision for integrating research between the atmospheric and hydrological science communities through the Consortium for the Advancement of Hydrological Sciences, Inc. (CUAHSI).


In a more applied vein, RAP engineers and scientists worked with the Denver Urban Drainage and Flood Control District to demonstrate the usefulness of NCAR’s Thunderstorm Identification, Tracking and Analysis (TITAN) system and the Auto-Nowcaster in improving short-term forecasts of flash floods in urban areas. A new program was launched in the United Arab Emirates to develop and implement a customized hydro-meteorological analysis and display system, a new decision support tool for water resource managers. RAP scientists, in collaboration with the American Water Works Association and ESIG, brought water utility planners and climate scientists together in a workshop to discuss the scientific basis of climate change and how decision makers could plan to address the impact of global warming on water resources.

Precipitation Enhancement

In addition to finding ways to better manage existing resources, RAP scientists work to scientifically assess the feasibility of increasing water supplies through cloud seeding. The rainfall enhancement assessment program in the United Arab Emirates entered its second phase with randomized seeding operations conducted over the summer months. Data from that field program and from a smaller effort in Saudi Arabia are currently being analyzed. An initial study to assess the feasibility of rainfall enhancement in Oman was completed with results indicating that there is sufficient summertime convection over the Oman Mountains to make cloud seeding feasible. In addition to these studies, RAP scientists continue to serve as expert resources, providing guidance and advice to governments around the globe interested in the potential of weather modification.

Surface Transportation Applications

 The effort to build a surface transportation program continued with RAP staff heavily involvement in several national initiatives to build advocacy for surface transportation research. The program development effort resulted in funding for new programs to improve road and bridge frost prediction for Peak Weather/Meteorlogix; to create a Weather Response System for traffic, incident, emergency management and highway maintenance for the Missouri Dept. of Transportation; and to develop and demonstrate a tactical decision support system for snow and ice control for AURORA, an international partnership of public agencies who collaborate on rod weather information systems research. 


RAP’s flagship program in the surface transportation arena continued to be the Maintenance Decision Support System effort for the Federal Highway Administration. In 2004 a second field demonstration was conducted in Iowa, and system enhancements were made in response to recommendations of maintenance operators there. Significant scientific lessons learned included confirmation that data fusion techniques used in the forecast system improved the forecasts; the use of “hot start” mesoscale models improved the 0-6 hour precipitation forecasts; probabilistic products were well-received by end users; and expansion of the rules of practice logic to include winter storm event characterization greatly improved the stability and accuracy of treatment recommendations.

A stakeholder group meeting was held in NCAR in July to discuss the program and the results of the field program. Seventy-five participants representing FHWA, 23 State DOTs, 23 commercial weather providers, and a variety of national laboratories and universities participated. A technology transfer workshop was held after the stakeholder meeting to facilitate the transfer of MDSS technologies into operations. In recognition of its significance as an end-to-end R&D program, RAP has nominated the MDSS program for UCAR’s 2004 Outstanding Performance Award for Scientific and Technical Advancement.

Assessment Activities


RAP’s Verification Group provides independent verification of forecasts and forecasting systems, a critical component of the technology transfer process. Much of the group’s work to date has focused on aviation applications. Working closely with NOAA/FSL the group evaluates the capabilities of experimental aviation weather products and advises the FAA and NWS on their readiness for consideration for operational status. In 2004 the group conducted major evaluations of two in-flight icing algorithms, a convective forecasting system, and a turbulence forecasting algorithm. The group also began to study the ability of the Current Icing Potential product to detect icing conditions above 18,000 ft. (currently the product is only operational at lower altitudes).

In addition to its important role in evaluating products, the group works to develop new statistical techniques and verification approaches. Highlights from 2004 include:

  • Development of a verification toolkit using the “R” programming language. The toolkit was made available to the general public on the R-project website.

  • Creation of new verification methodologies based on cross-validation for use in situations where independent data are not available for evaluating a forecast.

  • Progress in formulating an object-oriented approach for evaluating spatial forecasts of precipitation and convection. This approach, developed in collaboration with MMM, was applied to gridded precipitation forecasts from a 22-km version of the WRF model and produced much more information about forecast performance than can be obtained using standard verification statistics.

  • Initial development of new verification techniques for data-sparse regions.

  • Exploration of new verification methods to better represent the real value of a forecast to a particular user group (link to Model Verification in NWP).

USWRP: Societal Impacts Program (SIP)

Funded by NOAA and NSF, the Societal Impacts Program is a new collaborative effort with ESIG and COMET. SIP works to improve the societal gains from weather forecasting and minimize social and economic losses and damage from weather by infusing social science and economic research, methods, and capabilities into the planning, execution, and analysis of weather information, applications, and research directions. Much of the SIP work in 2004 focused on program development, hiring of the SIP team, and project initiation. New programmatic efforts focused on the development of a conceptual approach and work plan for a broad-based assessment of the sensitivity of all US economic sectors to weather impacts and benefit assessment of weather information, and creation of a Hurricane Forecast Socio-Economic Working Group (HFSEWG) to improve society’s understanding and use of hurricane forecasts and to inform the weather community of user impacts from, and needs and values for, current and improved hurricane forecasts.

Climate and Weather Impact Assessment Science Strategic Initiative

The NCAR Climate and Weather Impact Assessment Science Initiative (CWIASI) investigates how climate and weather create both hazards and opportunities for society and seeks to improve the ways in which scientific knowledge is generated and communicated to decision makers. RAP scientists led an effort to integrate elements of the hydrologic cycle, climate change science and conceptual models of ecosystem services within a water resource management model. This work is directed toward creation of an improved decision support for freshwater ecosystem services managers in the Sacramento, California, watershed.

Members of RAP’s Verification Group worked to develop new methods to assess extreme weather events such as icing, convection and turbulence which can have a major impact on aviation. Extreme value theory is being explored as a potentially useful new approach in forecasting these weather hazards because it focuses on properties of events that occur rarely or have an unusual magnitude. A related effort, in collaboration with ESIG, has produced an “extremes toolkit”, a user-friendly, interactive program for analyzing extreme value data using the R statistical programming language. The toolkit, with tutorial, is now available on the Web.



Director's Message |Table of Contents | Executive Summary |RAP Achievements
Education and Outreach | Community Service | Awards | Publications | People | ASR 2004 Home

National Center for Atmospheric Research University Corporation for Atmospheric Research National Science Foundation Annual Scientific Report - Home Atmospheric Chemistry Division Advanced Studies Program Atmospheric Chemistry Division Climate and Global Dynamics Division Environmental and Societal Impacts Group High Altitude Observatory Mesoscale & Microscale Meteorological Division Research Applications Program National Center for Atmospheric Research Scientific Computing Division