Group Members :
Shirley Murillo
Sean White
Russel St. Fleur
Nirva Morisseau-Leroy
Nick Carrasco
George Soukup
Neal Dorst
Jason Dunion
Sonia Otero
The hurricane wind field provides the forcing for waves and storm surge and interacts with land to produce a complex turbulent flow that provides the load cycling that leads to damage. This project seeks to describe the surface wind field for forecast, warning, and extreme wind climate purposes through the use of objective analysis and the latest technology in JAVA and database connectivity. The HRD Real-time Hurricane Wind Analysis System (H*Wind) is a distributed system that ingests realtime or retrospective tropical cyclone observations measured by land-, sea-, space-, and air-borne platforms into an object relational database, adjusts them to a common framework, and then graphically displays the data relative to the storm with interactive tools so scientists can quality control, objectively analyze, and visualize the information. The primary products of H*Wind help determine the storm's intensity, the extent of its damaging winds, and how the flow is affected by land and sea.
Link to project page: http://storm.aoml.noaa.gov
Accomplishments (link to pdfs):
Houston, S. H., W. A. Shaffer, M. D. Powell, and J. Chen, 1999: Comparisons of HRD and SLOSH surface wind fields in hurricanes: Implications for storm surge and wave modeling. Wea. Forecast., 14, 671-686.
Powell, M. D., and S. H. Houston, 1999: Comments on "A multiscale numerical study of Hurricane Andrew (1992). Part I: Explicit simulation and verification." Mon. Wea. Rev., 127, 1706-1710.
Coauthor, NRC Committee Report: 1999: Review of the need for a large-scale test facility for research on the effects of extreme winds on structures. National Research Council, National Academy Press, Washington D. C. ISBN-0-309-06483-X.
Powell, M. D., S. H. Houston, L. R. Amat, and N Morisseau-Leroy, 1998: The HRD real-time hurricane wind analysis system. J.Wind Engineer. and Indust. Aerodyn. 77&78, 53-64.
Powell, M. D., and S. H. Houston, 1998: Surface wind fields of 1995 Hurricanes Erin, Opal, Luis, Marilyn, and Roxanne at landfall. Mon Wea. Rev., 126, 1259-1273.
Coauthor, USWRP PDT-5 Report, 1998: Tropical Cyclones: Forecast problems and associated research opportunities. Bull. Amer. Met. Soc., 79, 305-323.
Coauthor, USWRP PDT-3 Report, 1997: Coastal Meteorology and Oceanography: Report of the third prospectus Development team of the USWRP to NOAA and NSF. Bull. Amer. Met. Soc., 77, 1578-1585.
Powell, M. D., S. H. Houston, and T. A. Reinhold, 1996: Hurricane Andrew's Landfall in South Florida. Part I: Standardizing measurements for documentation of surface wind fields. Weather Forecast., 11, 304-328.
Powell, M. D., and S. H. Houston, 1996: Hurricane Andrew's Landfall in South Florida. Part II: Surface Wind Fields and Potential Real-time Applications. Weather. Forecast., 11, 329-349.
Future Plans: Under the Joint Hurricane Testbed we will continue the effort to transition H*Wind to operations at NHC, CPHC, JTWC, and the Miami and Melbourne WFO's.
2. Hurricane Risk and Loss Projection
Principal Investigator : Mark Powell
Group Members :
George Soukup
Nirva Morisseau-Leroy
Neal Dorst
Chris Landsea
Collaborators :
S. Cocke (FSU)
L. Axe (FSU)
S. Gulati (FIU)
J. Pinelli (FIT)
K. Gurley (UF)
S. Hamid (FIU)
The extreme wind climate in hurricane threatened areas is insufficient to determine with statistical accuracy the average annual loss that might affect a location. Monte Carlo simulation models have been developed to improve risk assessment by simulating thousands of years of tropical cyclone activity based on the statistical properties of a limited (1900-present) record, and the assumption that the surface wind field may be adequately described by a few parameters: motion, minimum pressure, and radius of maximum wind. This project seeks to uncover the "black box" nature of proprietary risk models by developing an open, public model for the State of Florida in cooperation with colleagues at Florida International University, Florida State University, University of Florida, and Florida Institute of Technology. While building and improving the model, we will examine the sensitivity of results to selections of model parameters and assess the accuracy of model wind fields through comparison to observations.
Accomplishments:
Paper for the International Conference on Wind Engineering, June 2003 Lubbock TX
Future Plans:
The model will be prepared for submission to the Florida Commission on Hurricane Loss Projection as a candidate for certification as an insurance industry ratemaking tool.
3. Hurricane Landfall Forecast Accuracy
Principal Investigators :
Mark Powell
Sim Aberson
Hurricane forecasts in the Atlantic basin have improved at a rate of 1-2 % per year over the past 30 years. While this is a commendable improvement, only 15% of those forecasts crossed the U. S. coastline and 2% of those did not verify. This project assesses the accuracy of landfall forecasts by comparison to the observed position and time corresponding to the storm center crossing the coastline. Results thus far do not suggest a significant improvement in landfall position forecasts at any lead time period, although time of landfall forecasts show improvement at the 19-30 h period before forecast landfall. This information can be used by policy and planning officials to help set goals for scientific research programs. It is hoped that these results will motivate others to examine model landfall forecast performance and whether the current forecasts are approaching predictibility limits.
Accomplishments:
Powell, M. D., and S. D. Aberson, 2001: Accuracy of United States tropical cyclone landfall forecasts in the Atlantic basin 1976-2000. Bull. Amer. Met. Soc., 82, 2749-2767.
Future Plans: We will update the results as landfall forecasts and observations come in. We expect to update every five years and every ten years produce follow-on papers to track progress in U. S. landfall forecast accuracy.
4. Boundary Layer Structure and Dynamics
Principal Investigator : Mark Powell
Collaborators :
Gary Barnes (U. Hawaii)
Tim Reinhold (Clemson U.)
Peter Vickery (U. Western Ontario)
Much of what we knew about the boundary layer structure of hurricanes changed when GPS dropwindsondes were first dropped into hurricane eyewalls in 1997. Since then, analysis has shown the existence of well developed mixed layers in both specific humidity and potential temperature, and mean log wind profiles in the lowest 200 m. This research examines the marine boundary layer structure and variability in the hurricane and attempts to use individual and mean wind and thermodynamic profiles, together with insitu and remotely sensed information collected by the NOAA research aircraft to elucidate on important processes occuring in the surface layer including possible interactions with sea state, wind shear, and rainbands. Over coastal areas and inland, research focuses on describing the wind variability with time series analysis techniques and examining how obstacle roughness affects turbulence and the mean wind profile.
Results:
Powell, M.D., P.J. Vickery, and T.A. Reinhold, 2003: "Reduced drag coefficient for high wind speeds in tropical cyclones" Nature vol 422, March 20 pp.279-283
Wright, C.W., E.J. Walsh, D. Vandemark, W.B. Krabill, A.W. Garcia, S.H. Houston, M.D. Powell, P.G. Black, and F.D. Marks, 2001: Hurricane directional wave spectrum spatial variation in the open ocean. Journal of Physical Oceanography, 31(8):2472-2488.
Barnes, G. M. and M. D. Powell, 1995: Evolution of the inflow boundary layer of Hurricane Gilbert (1988). Mon. Wea. Rev., 123, 2348-2368.
Powell, M. D., 1990: Boundary layer structure and dynamics in outer hurricane rainbands. Part I: Mesoscale rainfall and kinematic structure. Mon. Wea.Rev., 118, 891-917.
Powell, M. D., 1990: Boundary layer structure and dynamics in outer hurricane rainbands. Part II: Downdraft modification and mixed layer recovery. Mon. Wea. Rev., 118, 918-938.
Future Plans: We will continue the approach followed in the Nature paper to explore heat and moisture exchange coefficient parameterizations and the effect of shoaling and breaking waves in shallow coastal ocean regions.
5. Hurricane Wind Field Reconstruction
Principal Investigator : Mark Powell
Group Members :
Jason Dunion
Shirley Murillo
Sean White
Collaborators :
Sam Houston (WFO Honolulu)
H. Winer (USACE)
H*Wind has proven to be an effective tool for retrospective hurricane studies to support a variety of applications. Observations from past hurricanes can be assembled and analyzed using the methods developed from hurricane landfall wind field reconstructions spanning 1979-present. Considerable time is spent in quality control and under some circumstances thewind observations are supplemented by using a wind field model such as that developed by Dr. Lloyd Shapiro of HRD. To date wind field reconstructions have been completed in support of Florida Bay ecosystem research with funding from NOAA's Coastal Ocean Program (Hurricanes Donna 1960 and the 1935 Labor Day Storm) and a Hurdat reanalysis (later stages of Hurricane Donna) funded by a grant to Dr. Landsea from the Risk Prediction Initiative of the Bermuda Biological Station. Presently, a reconstruction of 1965 Hurricane Betsy, and 2002 Hurricanes Isidore and Lili are in process with support grants from the U.S. Army Corps of Engineers New Orleans Office.
Results:
Houston, S. H., and M. D. Powell, 2003: Reconsturction of Significant Hurricanes affecting Florida Bay: The Great 1935 Hurricane and Hurricane Donna (1960). In press, J. Coastal Research.
Future Work:
Papers describing the Betsy, Lili, and Isidore reconstruction efforts will be produced. Analysis of additional storms affecting the New Orleans storm surge basin include Georges of 1998 and Andrew of 1992.
6. Tropical Cyclone Wind Exposure (Was ASOS Evaluation)
Principal Investigator : Mark Powell
Group Members :
Russel St. Fleur
Shirley Murillo
Nick Carrasco
Collaborators :
D. Bowman (NCDC)
D. Gilhousen (NDBC)
Grants from the USWRP allowed digital cameras to be distributed to WFOs in hurricane affected areas of the U. S. and its possessions. Following methodology posted at www.aoml.noaa.gov.hrd/asos Photographs were taken to document the wind exposure at over 200 automatic weather stations.
Results: Photo documentation is available at NCDC's station locator web site:
http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwdi~ASOSPhotos
as well as the NDBC site (For Coastal-Marine Automated Network stations):
http:// www.ndbc.noaa.gov
Future Plans:
A paper is being prepared for the Bulletin of the AMS: " Tropical Cyclone Winds at Landfall:The ASOS-CMAN Wind Exposure Documentation Project"