Garmin GXM 30 GXM 30 Owner's Manual for Marine/Aviation Products - Page 21

XM WEATHER FEATURES > FRONTS Fronts The Fronts feature displays lines indicating the leading edge of an air mass. This feature also displays pressure centers. Pressure centers are represented by a large Red "L" for low pressure centers or a large Blue "H" for high pressure centers. Pressure centers represent an area where pressure is measured to be either the highest or lowest relative to the surrounding area. Indicates a Low Pressure Center. A Low Pressure Center is an area where the measured pressure is lowest relative to the surrounding area. Moving away from a Low Pressure Center in any horizontal direction results in increased pressure. Winds flow counterclockwise around Low Pressure Centers in North America. Cold Front Warm Front Stationary Front Occluded Front Trough Indicates a High Pressure Center. Similar to a Low Pressure Center, a High Pressure Center is an area where the measured pressure is highest relative to the surrounding area. Moving away from a High Pressure Center in any horizontal direction results in decreased pressure. Winds flow clockwise around Low Pressure Centers in North America. GXM 30 XM Radio Smart Antenna Owner's Manual 14