B&G Deckman - Manual (Page 137)

Chapter 9: Wind and current forecasts
9.10
002 Pressure reduced to mean sea level
031 Wind direction in true degrees
032 Wind speed in metres per second
033 u-component of wind—east/west component of the wind.
Positive indicates wind is going towards the east, i.e. a
westerly wind, and vice versa
034 v-component of wind—north/south component of the wind.
Positive indicates wind is going towards the north, i.e. a
southerly wind, and vice versa
Essentially, 031 together with 032 give the same information as 033 and
034 but in a different form. You are unlikely to come across both of
these in the same GRIB file.
The first column shows the forecast type according to the codes
mentioned above. The third row of figures for each forecast section
shows the date and time the forecast was issued, and the time in hours
between the forecast and the present data (the middle number of the
three after the date and time). The rest of numbers give details such as
positions, but are difficult to interpret in this form.
To see the data in a more user-friendly form, select View>Select Data.
Select the data you wish to view by clicking on the arrow beside the
Forecast box (which shows the forecast type according to the codes
along with the issue date/time).
You will now see a set of figures in a table. At the top is the code for the
type of data selected followed by the date and time of issue and the
elapsed time since the issue. (Note that the data shown will be for the
forecast time only if this is 0, see below). The figures down the left hand
side of the display give the latitude and those along the top show the
longitude. The data is then shown in the grid. For instance Figure 9.7
shows data for 12:00 on 11th August '97 (twelve hours after the forecast
was issued at 00:00). At a position 70.008N, 27.500W (both underlined)
the expected u-component (east/west) of the wind is 5.59 metres per
second (circled)—or about 12 knots.