December 1996 FSL Forum
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December 1996 FSL Forum FSL Home Page |
Future of Turbulence Forecasting at FSL - In a previous Forum article, a summary of the turbulence forecasting effort at FSL was presented. One of the main difficulties in the verification of turbulence forecasting algorithms, either prognostic or diagnostic algorithms, is the lack of scientifically based turbulence observations. One possible solution to this problem is the in-situ measurements of turbulence from the NCAR algorithm under implementation and soon to be part of the ACARS suite of variables. Recently, however, vertical acceleration data from United Airlines' Boeing 757 fleet began to arrive at FSL. Preliminary examination of these data indicates that a new era in turbulence algorithm design and verification is feasible. One immediate benefit of the new data is continuous reports along the flight path at cruising altitudes in the upper troposphere. Such reports were almost nonexistent in the old pilot report data. Another benefit is the timely continuity of the reports, which will make it feasible to perform studies of the evolution of the turbulence fields in numerical models.
At FSL a new formulation has been developed to estimate turbulence intensity and turbulence dissipation rates using these vertical acceleration data and aircraft parameters. Turbulence dissipation rate is one of the key variables to define a universal turbulence metric and to begin an investigation into the possibility of initializing turbulence parameterization schemes in numerical weather prediction models. The quality of turbulence short- and long-range forecast products can also be improved by introducing corrections in the initial turbulence forecasts using actual ACARS data. The verification and calibration of diagnostic and prognostic turbulence formulations, in conjunction with the numerical models like MAPS and Eta, will continue to be our objective to improve the accuracy of turbulence forecast products at FSL. A second objective is to investigate the performance of the Burk-Thompson one-dimensional column model to be used with data from soundings or model output. This model could be run along the flight path of an aircraft with prior in-situ turbulence data to provide short-range forecasts.
Adrian Marroquin, a meteorologist in the Meteorological Applications Branch, will present a paper on "Diagnosing Convection-Induced Turbulence with Coarse Resolution Numerical Weather Prediction Models" at the AMS 7th Conference on Aviation, Range, and Aerospace Meteorology, Long Beach, CA, 2-7 February 1997.
The Impact of Data Quality and Internetwork Consistency on Central United States Precipitation Using Multiple Gage Networks - The construction of gage-measured precipitation analyses with reasonable spatial resolution (e.g., 50-km grid spacing) requires the inclusion of as many available observation sites as possible. Often these observations are from different networks with greatly different domains, gage resolution, site density, data quality, and other characteristics. Combining observations from these heterogeneous networks can significantly affect the credibility of analyses built from them. To examine the effects of such a combination, we have built simple prototype national-scale analyses of gage-measured daily precipitation over the continential United States. Three independent gage networks are included: hourly near-real-time observations from several observing networks assembled and disseminated by the National Centers for Environmental Prediction (NCEP) and cumulatively named the Hourly Acquisition Data System (HADS); daily precipitation totals from River Forecast Centers (also acquired from NCEP in near real time and referred to here as the RFC dataset); and retrospective hourly observations provided by cooperative observers and subsequently quality controlled and archived by the National Climatic Data Center as the Hourly Precipitation Dataset. Although each of these networks is nationwide in scope, we concentrate our study in the GCIP area of the central United States.
Edward Tollerud, a meteorologist in the Meteorological Applications Branch, will present a paper on this topic at the AMS 13th Conference on Hydrology in Long Beach. He will also present a paper at the same conference on "A Real-Time Gage-Measured Precipitation Display on the World Wide Web."
Improvements in Aviation Forecasts from the 40-km RUC - The 40-km version of MAPS/RUC has already demonstrated significant improvements over the 60-km version in the accuracy of upper-level wind forecasts and in reducing lower tropospheric temperature and relative humidity biases. Precipitation forecasts also show dramatic improvement. The 40-km MAPS is also shown to be nearly equal in 12-hour forecast skill in these areas to the 48-km Eta regional model. Further improvements in 40-km performance are expected with the addition of the three-dimensional variational analysis, MM5 cloud physics, and Burk-Thompson turbulence, all now in testing. Operational implementation of the 40-km Regional Update Cycle is expected in 1997. Future plans beyond that milestone include an hourly cloud analysis using satellite, radar, surface, and aircraft data combined with a model background.
Stanley Benjamin, Chief of the Regional Analysis and Prediction Branch, will present a paper on this topic at the AMS 7th Conference on Aviation, Range, and Aerospace Meteorology in Long Beach.
Scientific Basis for NAOS - How should the national weather services of North America allocate shrinking resources for meteorological observing systems and yet maintain or even improve forecast accuracy? That is the fundamental question addressed by the North American Observing System (NAOS) Program. The NAOS Council has set up a Test and Evaluation Working Group to formulate and test hypotheses relating to various observing system strategies. The tests employ data assimilation systems and numerical prediction models under the most realistic conditions possible. NAOS planners will analyze the results of these tests for guidance on how to fund cost-effective observing systems.
Thomas Schlatter, Chief of the Forecast Research Division, will present a paper on this topic at the AMS First Symposium on Integrated Observing Systems in Long Beach.
The Regional Observation Cooperative - The current design of the Regional Observation Cooperative (ROC) takes advantage of FSL's data, analysis, and communications infrastructure. Bringing the ROC data into FSL via the Denver WFO offers rapid improvements in QC and flexibility in the development of LAPS and other products for the members. As the ROC matures and as the NWS modernization progresses, the ROC software for QC and product generation will be ported to participating WFOs. Members will then send their data to and receive products from their local WFO. At that point, ROC software and expertise will be available for any WFO in the country.
Last October the first data from the Colorado DOT became available. Work is progressing on stabilizing the data feed to the Denver WFO and FSL. These data will be used in both the current LAPS and in the larger ROC LAPS. The first steps to upgrade the LAPS QC have been taken as well, and the first in the series of QC meetings was held in November. The first products, in the form of Colorado LAPS analyses, are available via the ROC homepage ( http://www.fsl.noaa.gov/frd/roc/roc.home page.html ). As the ROC LAPS comes online, those analyses will also be made available, along with data plots and other products.
Peter Stamus, a meteorologist from the Local Analysis and Prediction Branch, will present a paper on this topic at the AMS First Symposium on Integrated Observing Systems.
Data Storage and Retrieval System - A Mass Store System (MSS) was installed at FSL in 1994 to accommodate the data storage requirements of the laboratory. After initial acceptance testing, it became apparent that the system had to be augmented before it could be made available to users. Although we wanted a system comprising off-the-shelf hardware and software, it was necessary to develop the Data Storage and Retrieval System to provide more usable MSS availability for FSL users.
Joan Brundage, a meteorologist and branch chief from the Facility Division, will present a paper on this topic at the AMS 13th IIPS Conference, in Long Beach.
Local Data Manager Usage in the NIMBUS System - In support of the real-time meteorological data distribution efforts of FSL, the UCAR Unidata Program-developed Local Data Manager (LDM) serves as the standard for the transfer of meteorological data with FSL and in our distribution of data to sites outside FSL. The Facility Division developed the Networked Information Management client-Based User Service (NIMBUS) system to fulfill real-time meteorological data ingest, format translation, integration, and dissemination requirements. As the downstream data clients of NIMBUS have increased in number and volume requirements, LDM has had an increasing role in data distribution. LDM has also taken on a greater role in the distribution of data between NIMBUS nodes.
David Osburn, a systems analyst, will present a paper on this topic at the upcoming AMS 13th IIPS Conference.
The GOES Local Groundstation System - FSL has developed a GOES Local Groundstation System (GLGS) to ingest and process GVAR data from the GOES-8 and GOES-9 weather satellites. The system provides real-time imager and sounder data files to users in the FSL-standard netCDF format. The integration of the system into the Central Facility NIMBUS environment has enabled the use of a large set of shared software modules for data handling, while following FSL software development standards has facilitated code maintenance and portability. Satellite products generated by the system play an important role on FSL activities supporting the NWS modernization goals. Applications of the data include integration into FSL's LAPS cloud and moisture analyses, as well as display on FSL's meteorological workstations. Comparisons between the locally generated full-resolution imagery and the operational AWIPS GOES products have enabled FSL to evaluate the effects of AWIPS' reduced numerical resolution datasets on objective analyses which might be generated at an NWS forecast office. While the GLGS is operational, the system will continue to undergo development, particularly in the area of monitoring. Anticipated improvements include a real-time ingest status display, and a capability to estimate and track bit-error rates. Additionally, we will continue to seek performance enhancements to minimize latency in handling the very large GOES data stream.
Robert Lipschutz, a systems analyst from the Facility Division, will present a paper on this topic at the AMS 13th IIPS Conference.
Upgrades and Enhancements to the FSL Computer Network - The constantly evolving FSL computer network has grown from relatively slow point-to-point data links through shared disks, in the early 1980s, to a 100-Mbps Fiber Distributed Data Interface (FDDI) local area network (LAN) technology, in the 1990s. To achieve its modeling and research goals, FSL acquired high-speed UNIX workstations, servers, a massively parallel processor, resulting in an exponential growth in communications bandwidth needs. The network has undergone extensive upgrades to meet these bandwidth requirements.
Jerry Janssen, an electronics engineer in the Facility Division, will present a paper on this topic at the AMS 13th IIPS Conference.
NIMBUS: An Advanced Meteorological Data Acquisition, Processing, and Distribution System - NIMBUS has been fully functional since late 1994. This system was developed as part of a laboratory-wide transition to Open Systems technology, and it replaced the previous DEC VAX/VMS-based central facility that had supported FSL since 1982. NIMBUS is an integrated system that is implemented on several hosts in a multiplatform environment. It acquires, processes, stores, and distributes over 12 gigabytes of conventional and advanced meteorological data per day. The system has grown significantly during the last two years in response to FSL project and user requirements.
Glenda Wahl, a project leader from the Facility Division, will present a paper on this topic at the AMS 13th IIPS Conference.
FSL's Boundary Layer Profiler Data Acquisition Project - One of the functions of FSL is to provide a development testbed that can be used to validate new sensors which may become part of NOAA's observing system of the future. In order to improve forecasts, NOAA needs more high-quality observations, but does not have the financial resources to produce all of the data that could be of benefit. The recent proliferation of boundary layer profilers operated by other agencies presents the opportunity for NOAA to acquire data of potentially significant utility for little cost. To take advantage of this opportunity, FSL has begun a project to acquire BLP data from cooperating agencies, process them into quality-controlled products, and distribute them along with products from the NOAA Profiler Network.
Michael Barth, a computer specialist and branch chief from the Demonstration Division, will present a paper on this topic at the AMS First Symposium on Integrated Observing Systems in Long Beach.
Boundary Layer Profilers - Low-power profilers (mostly 915 MHz units manufactured by Radian Corporation) have begun operating around North America. There are about 65 boundary layer profilers either currently operating or planned for installation. FSL has begun cooperating with orther organizations to acquire boundary layer profiler wind and temperature data, which will be sent to the Profiler Control Center and processed into hourly, quality-controlled products. We are currently processing real-time data from 14 boundary layer profilers. These data soon will be available from the FSL real-time Website displays.
Profiler Data Availability - The graph below shows the profiler data availability on a weekly basis for the past year. The downward spikes on the left side of the graph are due to changes in procedures during the government shutdowns. During some summer months in previous years the data availability has been greatly reduced by lightning and power line surges, but not so much this year. The failure consensus rate has been cut in half over the past year since we implemented our program of rebuilding power amplifiers. We expect this to continue next year.
FSL has always placed great emphasis on developing a user interface that is easy to use so forecasters can perform their job more efficiently. The WFO-Advanced workstation design takes advantage of many years of experience with DARE and earlier workstations. FSL's approach to user interface design has always included a significant amount of prototype development and early involvement of the operational forecasters. The availability of the X-Window system and high performance workstations has provided challenges and new opportunties. Over the years many tools have become available that simplify the development of window-based user interfaces.
Herbert Grote will present a paper on this topic at the AMS 13th IIPS Conference.
An Object-Oriented Framework for Local Extensions to the WFO-Advanced Forecast Display Workstation, D2D - FSL has been engaged in the development and testing of a series of prototype workstations for use in the modernized NWS forecast offices. The central element of the latest system, WFO-Advanced, is the two-dimensional forecaster workstation known as D2D. Using a new capability in the D2D system, an extension framework, local forecasters and programmers in NWS offices can develop their own extensions to the display system. The extension framework is an object-oriented interface that makes local extensions possible. Such extensions could enable D2D users to display special kinds of data, interactively locate information in geographic databases, computer storm directions, and more.
Sean Kelly, a computer specialist in the Systems Development Division, will present a paper on this topic at the AMS 13th IIPS Conference.
The Application Interface for the WFO-Advanced Forecaster Workstation, D2D - To complement the D2D design, FSL developers created an efficient programmatic interface to simplify the integration of local applications into the system. In describing the functions of the D2D application interface, this paper (also to be presented at the same conference by Sean Kelly) covers how new and existing programs can become D2D applications, what requests they can send to the interface, and what notifications they receive from the interface. The paper also surveys the kinds of applications currently deployed along with the D2D software, and compares the application interface with the D2D extension framework, an alternative way for forecasters and developers to provide customized functions to D2D.
Monitoring an Operational Weather Forecast System Using the World Wide Web - The installation of WFO-Advanced workstations at the Denver NWS Forecast Office (WSFO) in May 1996 represents a significant milestone in the NWS modernization. Based on functional specifications for AWIPS, WFO-Advanced supports essentially all diagnostic and forecasting operations at the Denver WSFO. Components of WFO-Advanced include data ingest and management, user interface, display, and text generation. Each of these components needs to be monitored to ensure that the system operates as planned, providing the required support to WSFO operations. Experience gained in this monitoring effort can also be applied to the operation of the AWIPS Network Control Facility, whose responsibilities include remote monitoring of operations at AWIPS sites.
Joseph Wakefield, a meteorologist and project leader in the Systems Development Division, will present a paper on this topic at the AMS 13th IIPS Conference.
A Description of the Real-Time Verification System - The Real-Time Verification System (RTVS) is a versatile system designed as a real-time data ingest system, as well as a visualization and display system. The real-time function of the RTVS is transparent to the user, while the visualization feature allows the user to define statistical plots and time periods of interest. The RTVS comprises six modules that are uniquely developed but work to- gether to produce one easy-to-use verification system. The system is designed to be portable and also to allow outside users to access FSL's RTVS version, thus enabling access to FSL's local storage. It provides both development and forecasting verification capabilities. Current online capabilities for the RTVS include ingest and continuous verification of AIRMETs, RUC and Eta icing and turbulence algorithm grids, and many display features such as height series, time series, and scatterplots. Offline capabilities or functions not yet fully implemented on to the operational RTVS include subjective verification such as forecast and verifying observation displays, QC of surface and profiler variables, and additional displays such as boxplots. Future development includes verification of SIGMETs and other NWS forecasts, surface and upper-air SAVs, precipitation, ceiling, and visibility. Also to be implemented is the ability to limit statistical calculations to one of several geographic domains or individual stations. Additional Interactive Verification Visualization System (IVVS) capabilities include contingency tables, bar charts, and boxplots.
Jennifer Mahoney, a meteorologist in the Aviation Division, will present a paper on this topic at the AMS 7th Conference on Aviation, Range, and Aerospace Meteorology in Long Beach. She will also present a paper at the same meeting on "The Statistical evaluation of edited icing grids using the RTVS."
The Quality Control Component of the RTVS - The Verification Program in the Aviation Division evaluates the accuracy of the numerical models used to generate state-of-the-atmosphere variables (SAVs) and aviation-impact variables (AIVs), as well as aviation forecasts issued by the National Weather Service. The RTVS is being developed to provide immediate and long-term verification of the analyses and forecasts. An important step in forecast verification is the collection and quality control of verifying observations from various sources. To provide this step, an automated system, called the Real-Time Quality Control (RTQC) system, is under development at FSL. Collected data are run through an automated series of quality control checks. Flags are set to signify which tests were performed and whether the tests failed. The flags are added to the observation files so that individual users can determine how they want to apply the quality control results to their own needs.
Craig Hartsough, a meteorologist from the Aviation Division, will present a paper at the AMS 7th Conference on Aviation, Range, and Aerospace Meteorology, in Long Beach, that describes the format of the RTQC system, illustrates how individual quality control tests are used, and discusses the role of RTQC in the overall plan for RTVS.
The WFO-Advanced Text Subsystem User Interface - As part of the WFO-Advanced project, FSL has developed a set of text editing and display software for use by operational forecasters. This software builds upon lessons learned from operational use of the DARE text subsystem, borrowing heavily from successful ideas, while extending and updating them into a more portable and extensible system built using the Tcl/Tk toolkit.
Michael Biere, a systems analyst in the Modernization Division, will present a paper on this topic at the AMS 13th IIPS Conference.
Operational Use of WFO-Advanced at the Denver WSFO - The WFO-Advanced system was formally evaluated in a pseudo-operational environment in late 1995 (RT95). Meteorologists and operational forecasters who tested the system during RT95 indicated that it was nearly ready for operational use. Since then development of WFO-Advanced has continued based on the findings from this initial test. Last may FSL began deployment of WFO-Advanced at the Denver WSFO for operational testing. Two workstations were initially deployed in order to identify problems associated with operating at a location outside FSL using operational data feeds for satellite, numerical models, text, and WSR88-D radar. Results of the evaluations of the operational workstations are now available.
William (Woody) Roberts will present a paper on these operational results at the AMS 13th IIPS Conference in Long Beach.
Maintained by: Wilfred von Dauster