Reports from the National Data Buoy Center's Stations During the Passage of Hurricane Ike

01 - 14 September 2008
and During Ike's Extratropical Transition 14-15 September 2008

This report provides a summary of some of the wind speed parameters, the sea-level pressure, and wave parameter reports from the National Data Buoy Center's (NDBC) stations in the vicinity of Hurricane Ike's track. During Hurricane Ike, NDBC’s stations provided 1122 real-time hourly reports within 300 nautical miles of Ike’s track . Ike’s position data are based on the advisory positions and may change when the National Hurricane Center does its final report on Ike (when completed the report will appear in the 2008 Atlantic Season Archives at http://www.nhc.noaa.gov/2008atlan.shtml).

Descriptions of measurements and other terms of reference are provided in Appendix A at the end of the report. Hurricane Ike caused two station casualties – the failure of station SRST2 and the movement of station 42035 approximately 25 miles southwest of its original mooring location. One station, 42003, was a casualty of Hurricane Gustav and provided no measurements for Ike. NDBC was testing two buoys in the western Gulf of Mexico for the Tropical Atmosphere Ocean Array (TAO, see http://tao.noaa.gov/proj_overview/proj_overview_ndbc.shtml) and released the data in real-time as stations 42070 and 42071. Contact webmaster.ndbc@noaa.gov for more information on these two stations.

Data Plots for Selected Stations

For more information:


NOAA’s National Data Buoy Center: http://www.ndbc.noaa.gov/


NDBC’s Wave Measurements: http://www.ndbc.noaa.gov/wavemeas.pdf


For links to local National Weather Service Post-Storm Reports, see http://www.srh.noaa.gov/lch/ike/ikemain.php


For tidal information and meteorological measurements at tide stations, see the Quicklooks of the National Ocean Service’s Center for Operational Oceanographic Products and Services: http://tidesandcurrents.noaa.gov/quicklook_archive.shtml?year=2008&storm=IKE
National Hurricane Center’s Hurricane Ike Advisory Archive: http://www.nhc.noaa.gov/archive/2008/IKE.shtml?


National Weather Service’s Hydrometeorological Prediction Center’s Advisory Archive: http://www.hpc.ncep.noaa.gov/tropical/IKE/IKE_archive.shtml

In the report, Buoys have 5-digit station identifiers (e.g., 42001) while C-MAN stations have an alphanumeric station identifier (e.g., PLSF1).

Wind Speed: For stations in this report, wind speed is sampled at a rate of 1.0 Hz. For the Coastal-Marine Automated Network (C-MAN) station wind speeds are reported to NDBC in knots to a resolution of 0.1 knots. C-MAN wind speeds have been converted to meters per second (m/s) for this report, where 1 m/s = 1.94 knots. For the buoy stations wind speeds are reported to NDBC in meters per second to a resolution of 0.1 m/s. For the plot legends:


CWS: The average wind speed over a 10-minute period at the anemometer height. In this report, data are plotted at the time of the end of the valid 10-minute period.


MXGT1: The Peak 5-second gust during the past hour at the anemometer height. The time of MXGT1 is reported to the nearest minute, however, in this report data are plotted at the valid time of the hourly report.


WSPD1: The average wind speed for a period of 2 minutes for C-MAN stations and 8 minutes for buoy stations.


GUST1: The highest five-second average wind speed during the 2 or 8 minute sampling period.

Pressure: For stations in this report, pressure is sampled at a rate of 1.0 Hz and reported to a resolution of 0.1 hectoPascal (hPa). For the plot legends:

BARO1: Sea-level Pressure. Coastal-Marine Automated Network (C-MAN) stations average the pressure over 2 minutes. The buoy stations average the pressure over 8-minutes.

In addition 41041, 41043, 41046, 42056, and 42057 are equipped with Hurricane Supplemental Measurements:

Winds:

MX1MGT1: Maximum 1-minute wind speed during the previous hour.

Pressure:

MN1MSLP1: Lowest 1-minute sea-level pressure during the past hour when the sea-level pressure is less than 1008 hPa.

Wave: Sampling rate and durations for the wave systems are given in the footnote above for Table 2.

WVHGT: The significant wave height that represents the average of the highest one-third of the waves during the wave sampling period and is computed from the zeroth spectral moment (m0) as 4 * v m0 .

DOMPD: The Dominant Period that represents the wave period (time from between consecutive passes of the wave crests) of the waves with the most energy.

Closest Point of Approach (CPA): Time, bearing (degrees True), and distance (Nautical Miles) from the station to Hurricane Ike at CPA are computed using the positions from the National Hurricane Center's advisories that have been interpolated to hourly values for positions, wind speed (intensity), and central pressure.