An Extensive List of Acronyms
The list of measurements provided by buoys is rather extensive. Here’s a guide to the various measurements published by NDBC:
Wind Direction (WDIR)
Wind direction (the direction the wind is coming from in degrees clockwise from true N) during the same period used for WSPD.
Wind Speed (WSPD)
Wind speed (m/s) averaged over an eight-minute period for buoys and a two-minute period for land stations. Reported Hourly.
Wind Gust Speed (GST)
Peak 5 or 8 second gust speed (m/s) measured during the eight-minute or two-minute period. The 5 or 8 second period can be determined by payload.
Significant Wave Height (WVHT)
Significant wave height (meters) is calculated as the average of the highest one-third of all of the wave heights during the 20-minute sampling period.
Dominant Wave Period (DPD)
Dominant wave period (seconds) is the period with the maximum wave energy.
Average Wave Period (APD)
Average wave period (seconds) of all waves during the 20-minute period.
Mean Wave Direction (MWD)
Mean wave direction corresponding to energy of the dominant period (DPD). The units are degrees from true North just like wind direction.
Sea Level Pressure (PRES)
Sea level pressure (hPa). For C-MAN sites and Great Lakes buoys, the recorded pressure is reduced to sea level using the method described in NWS Technical Procedures Bulletin 291 (11/14/80).
Air Temperature (ATMP)
Air temperature (Celsius). For sensor heights on buoys, see Hull Descriptions. For sensor heights at C-MAN stations, see C-MAN Sensor Locations
Water Temperature (WTMP)
Sea surface temperature (Celsius). For sensor depth, see Hull Description.
Dewpoint Temperature (DEWP)
Dewpoint temperature taken at the same height as the air temperature measurement.
Station Visibility (VIS)
Station visibility (statute miles). Note that buoy stations are limited to reports from 0 to 1.9 miles.
Pressure Tendency (PTDY)
Pressure Tendency is the direction (plus or minus) and the amount of pressure change (hPa)for a three hour period ending at the time of observation.
Water Level (TIDE)
The water level in feet above or below Mean Lower Low Water (MLLW).
