February 1999 FSL

Forum Etcetera...


    Contents

    Blowdown

    Y2K Ready?

    FX-Net Development

    3-D Visualization

    FX-Connect

    Turbulence

    Etcetera

    Publications

    Contact Us

    Design:
    Wilfred von Dauster

    ...From the Director's Office

    FSL Honors

    Presidential Rank Award Presented to Dr. A.E. MacDonald – FSL director Sandy MacDonald received the Presidential Rank Award at a ceremony in Washington, D.C. This award recognizes career members of the Senior Executive Service who have demonstrated exceptional performance over time and received outstanding job evaluations over at least three years. Dr. MacDonald was also presented the additional honor of "Distinguished Executive" for his leadership in FSL and for FSL's contribution to the AWIPS program.

    Figure 1

    Sandy MacDonald (left) receiving the Presidential Rank Award from Vice President Al Gore.

    Bronze Medal Presented for the RUC-2 Model – The Office of Oceanic and Atmospheric Research in NOAA has announced the OAR Bronze Medal Awards. Among the recipients was a team from FSL for the development of the Rapid Update Cycle – version 2, an hourly analysis and prediction system, and its implementation into operations at NCEP. The RUC-2 is a significant improvement over the previous RUC in the frequency of assimilation, spatial resolution, sophistication of model physics, and overall performance.

    The government employees receiving this award are Dr. Stanley Benjamin, Dr. John Brown, Barry Schwartz, and Dr. Thomas Schlatter from FSL, and Lauren Morone and Geoffrey DiMego from NCEP. Equal contributions to the RUC-2 development and implementation were made by the following colleagues, working through NOAA Cooperative Institutes. Kevin Brundage (CIRA), Tracy Lorraine Smith (CIRA), and Tanya Smirnova (CIRES) deserve equal credit for this award.

    NOAA ERL Best Paper Award Presented to Dr. Gerald Browning – FSL researcher Gerald L. Browning was awarded this year's Environmental Research Laboratories' Outstanding Scientific Paper Award. The winning paper, coauthored with H.-O. Kreiss, titled "The Role of Gravity Waves in Slowly Varying in Time Mesoscale Motions" was published in the Journal of Atmospheric Sciences. Dr. Browning's research provides guidelines for meteorologists who study gravity waves, particularly for gauging the required accuracy of instruments. The paper also explains research specifics on the topic, i.e., how the measurements of any variable must be taken before the storm is over the observing site to ensure that only the gravity wave is being observed.

    Figure

2

    Gerald Browning (right) receiving NOAA's Outstanding Scientific Paper Award from Sandy MacDonald (center), with Cliff Matsumoto (left), head of the Cooperative Institute for Research in the Atmosphere.

    ...From the Forecast Research Division

    Dr. Thomas W. Schlatter, Chief

    The Operational RUC-2 – A study was conducted on the accuracy of wind forecasts provided by the operational RUC-2 model. Improvement was made in the intrinsic accuracy as well as in the time availability, both contributing to the overall improvement in the actual wind forecasts available for air traffic management purposes. The superiority of RUC-2 is significant in a direct sense for many programs in the FAA that use RUC data, but it also is important in providing background fields for the Integrated Terminal Weather System planned to run locally near large hubs across the United States.

    RUC-2 at NCEP – RUC-2 was implemented at the National Centers for Environmental Prediction (NCEP) last April, showcasing many upgraded features, including higher spatial resolution, a 1-hour cycle, assimilation of new datasets, and incorporation of advanced physical parameterizations. Work is ongoing toward an hourly cloud analysis combining the explicit cloud forecast in RUC-2 with data from satellites, radars, and surface stations. Implementation of a 3-D variational analysis is planned, along with an initial version of a 3-D cloud analysis. When NCEP acquires a Class-VIII computer, RUC-2 will implement a 20-km horizontal resolution. Further improvements in all physical parameterizations are also expected.

    ...From the Local Analysis and Prediction Branch

    Dr. John A. McGinley, Chief

    The LAPS Quasi-Operational Suite of Local Area Models – FSL generates a variety of local area numerical forecast model output in a quasi-operational environment as a part of LAPS. A primary goal of the Local Analysis and Prediction System (LAPS) is to demonstrate the utility and feasibility of a functional data assimilation and high-resolution prediction system in the local forecast office. LAPS collects all available local and central facility datasets to produce surface and upper-air analyses of state and derived atmospheric variables. The analyses are then available as initialization to local-area forecast models.

    A LAPS real-time environment has been functional over Colorado for more than five years. Hourly analyses are generated using a 61 x 61, 10-km horizontal grid with 21 isobaric levels. Quasi- operational local area forecasts to 12 hours are produced twice per day, initialized at 0000 and 1200 UTC, on the same horizontal LAPS grid. Model output is made available to the FSL daily weather briefing, to the LAPS Web page here, and to the LAPS Forecast Verification System.

    The Regional Atmospheric Modeling System (RAMS), developed at Colorado State University, was the first mesoscale forecast model implemented into the real-time environment. LAPS is designed to function with any complete mesoscale forecast model. To demonstrate this concept, the Penn State University/National Center for Atmospheric Research Mesoscale Model version 5 (MM5) was implemented in parallel with RAMS, which provides a unique opportunity to compare and contrast two different local area models using the same initial conditions.

    A third model, the hydrostatic Eta model obtained from the National Centers for Environmental Prediction (NCEP), has been added to the LAPS suite of quasi-operational models. The Eta implementation uses a workstation version of the model, which is now freely available to the meteorological community. FSL is also evaluating a nonhydrostatic version of the Eta model. Plans are to add this version of the nonhydro-static Eta model to the real-time environment.

    The LAPS analysis package will be included with the AWIPS meteorological workstations. Since all three forecast models (RAMS, MM5, and Eta) can use LAPS as initial conditions, it will be possible to run any of these models in the local forecast office. Tools are also available to prepare the larger domain NCEP forecast model output as forecast lateral boundary conditions for any of the models. Information and updates on this system are posted here.

    LAPS Part of the New Spacelift Weather Information System – FSL has been collaborating with the U.S. Space Agency and other organizations in the development of the Spacelift Weather Information System (SWIS), a new weather data processing and display system. SWIS will be deployed to integrate meteorological information from range instrumentation, external agencies, radar, and satellites. Since weather-related launch delays are very costly, weather officers and forecasters work under tremendous pressure to forecast accurate conditions for the launch window.

    LAPS will support the SWIS MetModel, which will provide weather forecasts with high time and location specificity. LAPS generates a 24-hour forecast every six hours, running on a double-nested grid of 16-km and 4-km grid spacing, and is adequate to resolve many of the important weather-producing phenomena such as sea breezes, fronts, and terrain modified flows. LAPS is initialized using four- dimensional data assimilation on each grid.

    ...From the Meteorological Applications Branch

    Dr. Cecilia M.I.R. Girz, Chief

    Combining Precipitation Networks: The Effect of Instrumentation and Site Distribution Differences – Decisions involving climatic precipitation analyses often hinge on issues of data quantity and data quality. We frequently face the question: At what point do the liabilities of questionable historical gauge measurements override the advantages of maximum density of observations? When several independent (and often substantially different) gauge networks are available, what are the characteristics of the data or of the analyses being undertaken that limit the value of their combination? These questions were addressed using observations from a network of hourly reporting stations, the Hourly Precipitation Dataset (HPD).

    A recent study revealed that the existence of multiple raingauge types in the historical dataset (spanning 50 years) does not appear to adversely affect the use of the full HPD in studies involving precipitation field analyses, area averages, or extreme value studies. This finding is particularly encouraging, since the search for extreme values is best undertaken with as long and complete a series of observations as possible. On the other hand, studies that require short-term precipitation frequencies will clearly need to recognize the differences between the two kinds of gauges.

    The substantial differences between the Hydrometeorological Automated Data System (HADS) and HPD results suggest that data quality is a determining factor for the quality of precipitation analyses.

    Turbulence Forecasting Algorithms: Calibration, Comparison, and Verification – A development verification tool is being used at FSL to calibrate, compare, and verify diagnostic turbulence forecasting algorithms with the 40- km RUC-2 model output and turbulence observations from pilot reports. In the first investigation, the five algorithms (Ri, Ellrod index, DTF3, DTF4, and DTF5) were calibrated, compared, and verifed for the period from 1 December 1997 to 10 January 1998. Probabilities of Detection (PODs) for yes- and no- turbulencne were computed for each algorithm over a range of thresholds. Because turbulence intensity is a function of an aircraft's mass, the verifying pilot reports were separated into two weight classes. (See article in this issue highlighting some of these results.)

    Global Air-ocean IN-situ System (GAINS) – A 48-hour flight of the latest GAINS prototype is planned for late spring. The 60-foot-diameter PIII balloon will demonstrate operation of the system at the nominal float altitude of 62,000 feet. The balloon will take sounding data on launch and at altitude, as well as transmit GPS-derived balloon location and balloon state data. Both line-of-sight telemetry and over-the-horizon (i.e., satellite) communications will be used. Interim tests using 16-foot prototypes are currently underway on the balloon's termination, radio, and solar-power systems. (An article on this project will appear in a future Forum.)

    ...From the Systems Development Division

    U. Herbert Grote, Chief

    Adding Productivity Tools to the WFO-Advanced Meteorological Workstation – As a central component of the AWIPS modernization effort, the WFO- Advanced workstation provides display and manipulation capabilities, as well as hooks that allow software developers to incorporate additional functionality. One example is MetGen, a productivity tool being developed at FSL for the generation of aviation weather products. Designed for forecasters to use at the NCEP Aviation Weather Center, MetGen generates Airmen's Meteorological Advisories (AIRMETS) and consistent high-resolution grids of the hazards for which AIRMETS are issued, such as icing and turbulence.

    Forecaster productivity tools will unburden forecasters from some time- consuming nonmeteorological tasks, while allowing the direct application of newly developed algorithm output to the forecast preparation process.

    Extensible Web Dissemination Graphical User Interface for National Weather Service Data – FSL has been developing a graphical user interface (GUI) for the Local Data Assimilation and Dissemination (LDAD) Web dissemination system. The explosive growth and variety of weather data being collected, generated, and checked for accuracy within the NWS Weather Forecast Offices necessitates more effective delivery of the information to end users. The delivery mechanism must be efficient, accessible, and able to present information in a format readily understandable to users from many backgrounds. The rapid rate of technology and information obsolescence requires that new information and new GUI features be integrated in the shortest possible time.

    The LDAD system will disseminate cross-correlated, quality-controlled weather, geographic, and alert information to local users. Since new information is constantly becoming available, an incremental and continuously upgradable capability was needed that allows new datasets to be easily integrated into the current application without requiring changes to the existing software.

    LDAD Observation Quality Control and Monitoring System – The LDAD system automates NWS field office interactions with local observation systems, spotter networks, cooperative observers, and emergency managers in the community. The system will enable each WFO to provide support for the acquisition, quality control, and integration of weather observations into the AWIPS processing environment; to facilitate two-way communications between the WFOs and state and local government agencies; and to disseminate AWIPS weather information using advanced visualization and integration techniques to local and state communities, and the public.

    FSL has been working on the implementation of the Quality Control and Monitoring System chosen for AWIPS Build 4.2. The initial version of the system utilizes QC checks and monitoring procedures originally developed as part of a surface assimilation system that was developed at FSL in 1986 and has been running at NCEP since 1989. Quality control results from the system have been used for several years by both the ASOS and profiler monitoring centers to help identify erroneous observations and surface stations with hardware or software maintenance problems. Planned upgrades include the incorporation of additional NWS-specified techniques for the quality control of AWIPS data, enhancements to the existing QC techniques, improved visualization, and the incorporation of new station and observation types.

    ...From the Aviation Division

    Michael J. Kraus, Chief

    Development of the Aviation Digital Data Service – FSL is involved in the development of the Aviation Digital Data Service (ADDS), a weather information and data distribution component of the Aviation Gridded Forecast System (AGFS). ADDS provides the aviation community with digital and graphical analyses, forecasts, and observations of key meteorological variables. It will enable aviation users to acquire route-specific graphics of key aviation impact variables (AIVs), such as icing, turbulence, and convection; meteorological observations; and grids of AIVs appropriate for ingest by commercial flight planning systems and FAA automation systems. ADDS will also enable AIV developers to acquire feedback regarding the operational utility of new products. Two more versions of ADDS will be developed during the next two years.

    Using the Real-Time Verification System at the Aviation Weather Center – As forecasters strive to improve the accuracy of their predictions, they recognize the critical need to track the performance of their own forecast products on a real-time basis. The Real-Time Verification System (RTVS) is helping the FAA to generate more accurate and accessible weather forecasts, and to improve performance and develop user-friendly products. The RTVS provides a mechanism for managers and forecasters to evaluate the quality of the current products. First, a statistical baseline is developed for AWC products and then improvements to those products are tracked. The RTVS also provides tools used to support the generation of experimental products.