The
Mean Sea Level
pressure field is plotted together with
Reduced
Pressure (millibars).
In some cases the reference level
for reduced pressure is set to 0m or sea level. In other cases it is set
to an elevation more representative of the station elevations, especially
in mountainous areas.
Surface Wind Barbs are also plotted in knots.
Wind barbs show wind direction and speed. A barb pointing to the left
means the wind is from the west. Each flag is 10 knots (11.5 mph), and half
flags are 5 knots.