Search Results

You are looking at 1 - 7 of 7 items for

  • Author or Editor: Shirley T. Murillo x
  • All content x
Clear All Modify Search
Edward N. Rappaport, Jiann-Gwo Jiing, Christopher W. Landsea, Shirley T. Murillo, and James L. Franklin

The Joint Hurricane Testbed (JHT) is reviewed at the completion of its first decade. Views of the program by hurricane forecasters at the National Hurricane Center, the test bed's impact on forecast accuracy, and highlights of the top-rated projects are presented. Key concerns encountered by the test bed are identified as possible “lessons learned” for future research-to-operations efforts. The paper concludes with thoughts on the potential changing role of the JHT.

Full access
Shirley T. Murillo, Wen-Chau Lee, Michael M. Bell, Gary M. Barnes, Frank D. Marks Jr., and Peter P. Dodge

Abstract

A plausible primary circulation and circulation center of a tropical cyclone (TC) can be deduced from a coastal Doppler radar using the ground-based velocity track display (GBVTD) technique and the GBVTD-simplex algorithm. The quality of the retrieved primary circulation is highly sensitive to the accuracy of the circulation center that can only be estimated from the degree of scattering of all possible centers obtained in GBVTD-simplex analyses from a single radar in real TCs. This study extends previous work to examine the uncertainties in the GBVTD-simplex-derived circulation centers and the GBVTD-derived primary circulations in Hurricane Danny (1997) sampled simultaneously from two Doppler radars [Weather Surveillance Radar-1988 Dopplers (WSR-88Ds) in Mobile, Alabama, and Slidell, Louisiana] for 5 h.

It is found that the mean difference between the individually computed GBVTD-simplex-derived centers is 2.13 km, similar to the estimates in previous studies. This value can be improved to 1.59 km by imposing time continuity in the radius of maximum wind, maximum mean tangential wind, and the center position in successive volumes. These additional physical criteria, not considered in previous work, stabilized the GBVTD-simplex algorithm and paved the way for automating the center finding and wind retrieval procedures in the future.

Using the improved set of centers, Danny’s axisymmetric tangential wind structures retrieved from each radar showed general agreement with systematic differences (up to 6 m s−1) in certain periods. The consistency in the wavenumber-1 tangential winds was not as good as their axisymmetric counterparts. It is suspected that the systematic differences in the axisymmetric tangential winds were caused by the unresolved wavenumber-2 sine components rather than from the relatively small cross-beam mean wind components in Danny.

Full access
Rajul E. Pandya, David R. Smith, Donna J. Charlevoix, Wayne Hart, Marianne J. Hayes, Shirley T. Murillo, Kathleen A. Murphy, Diane M. Stanitski, and Thomas M. Whittaker
Full access
Paul R. Harasti, Colin J. McAdie, Peter P. Dodge, Wen-Chau Lee, John Tuttle, Shirley T. Murillo, and Frank D. Marks Jr.

Abstract

The NOAA/NWS/NCEP/Tropical Prediction Center/National Hurricane Center has sought techniques that use single-Doppler radar data to estimate the tropical cyclone wind field. A cooperative effort with NOAA/Atlantic Oceanographic and Meteorological Laboratory/Hurricane Research Division and NCAR has resulted in significant progress in developing a method whereby radar display data are used as a proxy for a full-resolution base data and in improving and implementing existing wind retrieval and center-finding techniques. These techniques include the ground-based velocity track display (GBVTD), tracking radar echoes by correlation (TREC), GBVTD- simplex, and the principal component analysis (PCA) methods.

The GBVTD and TREC algorithms are successfully applied to the Weather Surveillance Radar-1988 Doppler (WSR-88D) display data of Hurricane Bret (1999) and Tropical Storm Barry (2001). GBVTD analyses utilized circulation center estimates provided by the GBVTD-simplex and PCA methods, whereas TREC analyses utilized wind center estimates provided by radar imagery and aircraft measurements. GBVTD results demonstrate that the use of the storm motion as a proxy for the mean wind is not always appropriate and that results are sensitive to the accuracy of the circulation center estimate. TREC results support a previous conjecture that the use of polar coordinates would produce improved wind retrievals for intense tropical cyclones. However, there is a notable effect in the results when different wind center estimates are used as the origin of coordinates. The overall conclusion is that GBVTD and TREC have the ability to retrieve the intensity of a tropical cyclone with an accuracy of ∼2 m s−1 or better if the wind intensity estimates from individual analyses are averaged together.

Full access
Rajul E. Pandya, David R. Smith, Donna J. Charlevoix, Genene M. Fisher, Shirley T. Murillo, Kathleen A. Murphy, Diane M. Stanitski, and Thomas M. Whittaker
Full access
Rajul Pandya, David Smith, Steven A. Ackerman, Priti P. Brahma, Donna J. Charlevoix, Susan Q. Foster, Volker Karl Gaertner, Thomas F. Lee, Marianne J. Hayes, Anthony Mostek, Shirley T. Murillo, Kathleen A. Murphy, Lola Olsen, Diane M. Stanitski, and Thomas Whittaker

Abstract

No Abstract available.

Full access
Rajul E. Pandya, David R. Smith, Donna J. Charlevoix, Susan Q. Foster, Robert Hart, Marianne J. Hayes, Marjorie McGuirk, Shirley T. Murillo, Kathleen A. Murphy, Diane M. Stanitski, and Thomas M. Whittaker
Full access