200mb Winds

• Purple shading indicates the speed of the winds at the 200 millibar level, in meters per second. This altitude is near the level of the core of the jet stream. So the tracks of the jet streams can be seen very clearly.
• The streamlines indicate the direction of flow of the wind, which is generally from west to east throughout most of the subtropics, mid- and high-latitudes.
• The color of the streamlines indicates a relative measure of divergence of the flow in the upper troposphere. Orange and red indicates strong divergence at upper levels, usually associated with strong vertical velocities in the middle troposphere, and severe weather/heavy rainfall.

Precipitable Water and Convective Available Potential Energy (CAPE)

• The shaded contours indicate total precipitable water in the atmosphere. Precipitable water is the total depth of liquid water that would result if all water vapor contained in a vertical column of air could be "wrung out", leaving the air completely dry. It indicates the total humidity of the air above a location, and is a good indicator of the amount of moisture potentially available to supply rainfall.
• The red contour lines indicate the amount of CAPE in the atmosphere, which is a good indicator of the potential for strong thunderstorms and severe weather. High values of CAPE indicate that most (but not necessarily all) conditions exist for strong thunderstorms.