Since 1996 the Hurricane Research Division has participated in the H*Wind Project. The purpose is to develop an integrated tropical cyclone observing system in which wind measurements from a variety of observation platforms could be used to develop an objective analysis of the distribution of wind speeds in a hurricane.
An HRD wind analysis requires the input of all available surface weather observations (e.g., ships, buoys, coastal platforms, surface aviation reports, reconnaissance aircraft data adjusted to the surface, etc.). Observational data are downloaded on a regular schedule and then processed to fit the analysis framework. This includes the data sent by NOAA P3 and G4 research aircraft during the HRD hurricane field program, including the Step Frequency Microwave Radiometer measurements of surface winds, as well as U.S. Air Force Reserves (AFRES) C-130 reconnaissance aircraft, remotely sensed winds from the polar orbiting SSM/I and ERS, the QuikScat platform and TRMM microwave imager satellites, and GOES cloud drift winds derive from tracking low level near-infrared cloud imagery from these geostationary satellites. These data are composited relative to the storm over a 4-6 hour period. All data are quality controlled and processed to conform to a common framework for height (10 m or 33 feet), exposure (marine or open terrain over land), and averaging period (maximum sustained 1 minute wind speed) using accepted methods from micrometeorology and wind engineering (Powell et al., 1996, Powell and Houston, 1996). Background on the HRD Surface Wind Analysis System is available at: http://www.aoml.noaa.gov/hrd/Storm_pages/surf_background.html
The loop below shows an animation of the HRD sustained wind analysis for Irene from 1330 UTC on 26 August through 2230 UTC on 27 August. The Wind Analyses created by NOAA’s Hurricane Research Division for Irene are available at: http://www.aoml.noaa.gov/hrd/Storm_pages/irene2011/wind.html
A comparison of the NHC sustained wind forecast for 1600 UTC 27 August as viewed in the Hurrevac software and the HRD sustained wind analysis valid 1630 UTC 27 August which is based on a variety of data from 0700-1330 UTC is shown below.
The graphic below shows the observed sustained winds and wind gusts across the North Carolina coast and coastal waters from several buoys or coastal locations. The track of Irene’s circulation center is shown in red. These reports were obtained from the National Data Buoy Center: http://www.ndbc.noaa.gov/
Finally, wind forecasts from the NDFD valid at 15 UTC (left) and 18 UTC (right) on 27 August are shown below. The sustained wind forecasts below verify fairly well in the coastal region with other subjective analysis (not shown) suggesting that the inland sustained wind forecasts were well overdone. Collaboration issues are also easily noted.