• Ayotte, K., 2008: Computational modelling for wind energy assessment. J. Wind Eng. Ind. Aerodyn., 96, 15711590.

  • Britter, R., Hunt J. , and Richards K. , 1981: Air flow over a two-dimensional hill: Studies of velocity speed-up, roughness effects and turbulence. Quart. J. Roy. Meteor. Soc., 107, 91110.

    • Search Google Scholar
    • Export Citation
  • Caribbean Community Secretariat, 1989: Caribbean Uniform Building Code. Part 2—Structural design requirements. Georgetown, Guyana, 218 pp.

  • Harper, B., Kepert J. , and Ginger J. , 2010: Guidelines for converting between various wind averaging periods in tropical cyclone conditions. WMO/TD-1555, 52 pp.

  • Henderson, D., Ginger J. , Leitch C. , Boughton G. , and Falck D. , 2006: Tropical Cyclone Larry: Damage to buildings in the Innisfail area. CTS Tech. Rep. TR51, Cyclone Testing Station, School of Engineering, James Cook University, Townsville, QLD, Australia, 98 pp.

  • Houston, S., Forbes G. , and Chiu A. , 2002: Impacts of Super Typhoon Paka’s (1997) winds on Guam: Meteorological and engineering perspectives. Nat. Hazards Rev., 3, 3647.

    • Search Google Scholar
    • Export Citation
  • Hunt, J., Leibovich S. , and Richards K. , 1988: Turbulent shear flows over low hills. Quart. J. Roy. Meteor. Soc., 114, 14351470.

  • Jackson, P., and Hunt J. , 1975: Turbulent wind flow over a low hill. Quart. J. Roy. Meteor. Soc., 101, 929955.

  • Kepert, J., 2005: Objective analysis of tropical cyclone location and motion from high-density observations. Mon. Wea. Rev., 133, 24062421.

    • Search Google Scholar
    • Export Citation
  • Lawrence, M., Avila L. , Beven J. , Franklin J. , Pasch R. , and Stewart S. , 2005: Atlantic hurricane season of 2003. Mon. Wea. Rev., 133, 17441773.

    • Search Google Scholar
    • Export Citation
  • Lemelin, D., Surry D. , and Davenport A. , 1988: Simple approximations for wind speed-up over hills. J. Wind Eng. Ind. Aerodyn., 28, 117127.

    • Search Google Scholar
    • Export Citation
  • Mason, P., 1986: Flow over the summit of an isolated hill. Bound.-Layer Meteor., 37, 385405.

  • Mason, P., and Sykes R. , 1979: Flow over an isolated hill of moderate slope. Quart. J. Roy. Meteor. Soc., 105, 383395.

  • Mason, P., and King J. , 1985: Measurements and predictions of flow and turbulence over an isolated hill of moderate slope. Quart. J. Roy. Meteor. Soc., 111, 617640.

    • Search Google Scholar
    • Export Citation
  • Miller, C., and Davenport A. , 1998: Guidelines for the calculation of wind speed-ups in complex terrain. J. Wind Eng. Ind. Aerodyn., 74–76, 189197.

    • Search Google Scholar
    • Export Citation
  • Mortensen, N., Landberg L. , Troen I. , and Petersen E. , 1993: Wind analysis and application program WAsP: User’s guide. Risø-I-666 (EN), Risø National Laboratory, Roskilde, Denmark, 133 pp.

  • Powell, M., and Houston S. , 1996: Hurricane Andrew’s landfall in south Florida. Part II: Applications to real-time analysis and preliminary damage assessment. Wea. Forecasting, 11, 329349.

    • Search Google Scholar
    • Export Citation
  • Powell, M., and Houston S. , 1998: Surface wind fields of 1995 Hurricanes Erin, Opal, Luis, Marilyn, and Roxanne at landfall. Mon. Wea. Rev., 126, 12591273.

    • Search Google Scholar
    • Export Citation
  • Powell, M., Houston S. , and Reinhold T. , 1996: Hurricane Andrew’s landfall in south Florida. Part I: Standardizing measurements for documentation of surface wind fields. Wea. Forecasting, 11, 304328.

    • Search Google Scholar
    • Export Citation
  • Powell, M., Houston S. , Amat L. , and Morisseau-Leroy N. , 1998: The HRD Real-Time Hurricane Wind Analysis System. J. Wind Eng. Ind. Aerodyn., 77–78, 5364.

    • Search Google Scholar
    • Export Citation
  • Powell, M., Vickery P. , and Reinhold T. , 2003: Reduced drag coefficient for high wind speeds in tropical cyclones. Nature, 422, 279283.

    • Search Google Scholar
    • Export Citation
  • Rowe, M., 2003: Roof damage by hurricane force winds in Bermuda—The Fabian experience. Dept. of Environmental Protection, Government of Bermuda, 41 pp.

  • Salmon, J., Bowen A. , Hoff A. , Johnson R. , Mickle R. , Taylor P. , Tetzlaff G. , and Walmsley J. , 1988a: The Askervein Hill project: Mean wind variations at fixed heights above ground. Bound.-Layer Meteor., 43, 247271.

    • Search Google Scholar
    • Export Citation
  • Salmon, J., Teunissen H. , Mickle R. , Taylor P. , Tetzlaff G. , and Walmsley J. , 1988b: The Kettles Hill project: Field observations, wind tunnel simulations and numerical model predictions for flow over a low hill. Bound.-Layer Meteor., 43, 309343.

    • Search Google Scholar
    • Export Citation
  • Taylor, P., Walmsley J. , and Salmon J. , 1983: A simple model of neutrally stratified boundary-layer flow over real terrain incorporating wavenumber dependent scaling. Bound.-Layer Meteor., 26, 169189.

    • Search Google Scholar
    • Export Citation
  • Walker, G., Reardon G. , and Jancauskas E. , 1988: Observed effects of topography on the wind field of Cyclone Winifred. J. Wind Eng. Ind. Aerodyn., 28, 7988.

    • Search Google Scholar
    • Export Citation
  • Walmsley, J., Salmon J. , and Taylor P. , 1982: On the application of a model of boundary-layer flow over low hills to real terrain. Bound.-Layer Meteor., 23, 1746.

    • Search Google Scholar
    • Export Citation
  • Walmsley, J., Taylor P. , and Keith T. , 1986: A simple model of neutrally stratified boundary-layer flow over complex terrain with surface roughness modulations (MS3DJH/3R). Bound.-Layer Meteor., 36, 157186.

    • Search Google Scholar
    • Export Citation
  • Weng, W., Taylor P. , and Walmsley J. , 2000: Guidelines for airflow over complex terrain: Model developments. J. Wind Eng. Ind. Aerodyn., 86, 169186.

    • Search Google Scholar
    • Export Citation
  • Weng, W., Taylor P. , and Salmon J. , 2010: A 2-D numerical model of boundary-layer flow over single and multiple surface condition changes. J. Wind Eng. Ind. Aerodyn., 98, 121132.

    • Search Google Scholar
    • Export Citation
  • Wieringa, J., 1993: Representative roughness parameters for homogeneous terrain. Bound.-Layer Meteor., 63, 323363.

  • WMO, 2008: Guide to Meteorological Instruments and Methods of Observation. 7th ed. WMO-8, 681 pp.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 450 283 0
PDF Downloads 354 193 0

Topographic Speed-Up Effects and Observed Roof Damage on Bermuda following Hurricane Fabian (2003)

View More View Less
  • 1 University of Western Ontario, London, Ontario, Canada
  • | 2 Atmospheric and Environmental Research, Lexington, Massachusetts
  • | 3 Risk Management Solutions (Asia Risk Centre), Newark, California
Restricted access

Abstract

In this study the impacts of the topography of Bermuda on the damage patterns observed following the passage of Hurricane Fabian over the island on 5 September 2003 are considered. Using a linearized model of atmospheric boundary layer flow over low-slope topography that also incorporates a model for changes of surface roughness, sets of directionally dependent wind speed adjustment factors were calculated for the island of Bermuda. These factors were then used in combination with a time-stepping model for the open water wind field of Hurricane Fabian derived from the Hurricane Research Division Real-Time Hurricane Wind Analysis System (H*Wind) surface wind analyses to calculate the maximum 1-min mean wind speed at locations across the island for the following conditions: open water, roughness changes only, and topography and roughness changes combined. Comparison of the modeled 1-min mean wind speeds and directions with observations from a site on the southeast coast of Bermuda showed good agreement between the two sets of values. Maximum open water wind speeds across the entire island showed very little variation and were of category 2 strength on the Saffir–Simpson scale. While the effects of surface roughness changes on the modeled wind speeds showed very little correlation with the observed damage, the effect of the underlying topography led to maximum modeled wind speeds of category 4 strength being reached in highly localized areas on the island. Furthermore, the observed damage was found to be very well correlated with these regions of topographically enhanced wind speeds, with a very clear trend of increasing damage with increasing wind speeds.

Corresponding author address: Craig Miller, Dept. of Civil and Environmental Engineering, University of Western Ontario, London ON N6A 5B9, Canada. E-mail: cmiller@eng.uwo.ca

Abstract

In this study the impacts of the topography of Bermuda on the damage patterns observed following the passage of Hurricane Fabian over the island on 5 September 2003 are considered. Using a linearized model of atmospheric boundary layer flow over low-slope topography that also incorporates a model for changes of surface roughness, sets of directionally dependent wind speed adjustment factors were calculated for the island of Bermuda. These factors were then used in combination with a time-stepping model for the open water wind field of Hurricane Fabian derived from the Hurricane Research Division Real-Time Hurricane Wind Analysis System (H*Wind) surface wind analyses to calculate the maximum 1-min mean wind speed at locations across the island for the following conditions: open water, roughness changes only, and topography and roughness changes combined. Comparison of the modeled 1-min mean wind speeds and directions with observations from a site on the southeast coast of Bermuda showed good agreement between the two sets of values. Maximum open water wind speeds across the entire island showed very little variation and were of category 2 strength on the Saffir–Simpson scale. While the effects of surface roughness changes on the modeled wind speeds showed very little correlation with the observed damage, the effect of the underlying topography led to maximum modeled wind speeds of category 4 strength being reached in highly localized areas on the island. Furthermore, the observed damage was found to be very well correlated with these regions of topographically enhanced wind speeds, with a very clear trend of increasing damage with increasing wind speeds.

Corresponding author address: Craig Miller, Dept. of Civil and Environmental Engineering, University of Western Ontario, London ON N6A 5B9, Canada. E-mail: cmiller@eng.uwo.ca
Save