WSR-88D Tropical Cyclone Algorithm Working Group Server
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Updated Tuesday, 27 October 1998
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The Office of the Federal Coordinator for Meteorology and the WMO have established statements recommending the development of tropical cyclone algorithms for use with landbased Doppler radars, and in particular WSR-88D radars:
We are organizing an international working group (Australia, Canada, France, India, Japan, Taiwan, and the United States) to develop and systematically test new and/or existing single Doppler radar algorithms for tropical cyclone detection, tracking, and wind field analysis.
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A two phase process is envisioned to develop operational tropical cyclone algorithms. Phase I entails the organization of a working group of scientists interested in the problem of developing tropical cyclone algorithms for single Doppler radars. Participation in the working group is voluntary, as we have no funding source ready to sponsor the development of new algorithm ideas. However, in order develop and test ideas for possible tropical cyclone algorithms members of the working group would be given free access to:
The working group will meet periodically (every 6 mon.) to discuss progress and make plans for future efforts.
During Phase II proposed algorithms will be put on a common workstation at NHC and undergo detailed testing using the whole 1995 WSR-88D data set. At the end of Phase II we should have a short list of algorithms for the Operations Support Facility (OSF) to implement. It is hoped that Phase II efforts will be eligible for funding under NOAA or the Office of the Federal Coordinator.
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We must also examine existing WSR-88D algorithms (e.g., mesocyclone, TVS,
rainfall, etc.) for use in tropical cyclone conditions:
Dave Sharp (SOO, NWS/KMLB) will coordinate an effort to evaluate current algorithm performance in tropical cyclones with Colin McAdie (NHC), Stacy Stewart (OSF) and other interested SOOs.
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In 1995 Hurricanes Erin, Jerry, and Opal were observed by WSR-88D radars over Florida and surrounding waters. At the same time a number of complimentary data sets were collected by the NOAA WP-3D airborne radars, NCAR CP-2 radar, and AFRES WC-130 aircraft. These data sets are unique, including measurements from multiple platforms and instruments. It provides an opportunity to systematically test and certify many of the algorithms and provides a basis for developing new algorithms.
In Phase I, 2 h of WSR-88D level II data from Hurricane Erin are available on an FTP site for use in algorithm development. Erin was chosen to take advantage of the excellent WSR-88D coverage of the storm during its lifetime as it made landfall along the east coast and panhandle of Florida.
The first hour of data (10-11 volume scans) are from the Melbourne, FL WSR-88D (KMLB), 0600-0700 UTC, 2 August 1995, during Erin's landfall along the east coast of Florida ( of KMLB base reflectivity or base velocity for this time are ). The second hour of data (10-11 volume scans) are from the Mobile, AL WSR-88D (KMOB), 1600-1700 UTC, 3 August 1995, during Erin's second landfall along the Florida panhandle . The volume scans are stored in the WSR-88D level II format. Documentation on the level II data format and subroutines to decode the data are also on the FTP site.
KMLB | KMOB |
We also plan to include an analog data set of a model wind field sampled from a simulated WSR-88D (e.g., Rankin vortex, divergent flow, combinations, etc.), for which we know the properties of the flow. The model data set would be a useful tool for algorithm development, and for intercomparison of results from the different algorithms. We are constructing such an analog data set and make it available as soon as possible.
Roughly 6 months after the data is made available via FTP the working group will reconvene at a convenient location and time to evaluate algorithm development and performance. The results from all the algorithms will be compared to independent data sources. A nice aspect of the Erin data set is that a number of independent data sources are available to assess the storm's position, track, kinematic structure, and rainfall. These independent data sets include:
The first three data sets are available at HRD and can be used to evaluate the algorithm performance.
Minutes of Vail Meeting 11 October 1995 (1 December 1995)
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Updated Tuesday, 27 October 1998