Key Points

 

Observed Winds

represented by wind barbs

The symbol highlighted in yellow (in the diagram above) is known as a "Wind Barb". The wind barb indicates the wind direction and wind speed.

 

Wind Barbs

determining wind direction

Wind barbs point in the direction "from" which the wind is blowing. In the case of the diagram below, the orientation of the wind barb indicates winds from the Northeast.

 

 

 

Observed Dew Point Temperature

indicates the amount of moisture in the air

The value highlighted in yellow located in the lower left corner (in the diagram above) is the dew point temperature in degrees Fahrenheit. In this example, the reported dew point temperature is 58 degrees.

 

Identifying Tropical Air Masses

on a map of surface observations

Below is a map of surface observations and the leading edge of a tropical air mass surging northward into the Ohio Valley has been highlighted in red. Southerly winds behind the boundary signify the continued northward transport of warm moist air.

 

Below is a map of surface observations and the leading edge of a large arctic air mass blanketing much of the United States has been highlighted by the blue line. The center of this air mass is a high pressure center located in northern Montana (indicated by the blue "H").