Garmin GXM 30A - Manual (Page 20)

3 GXM 30A XM Radio Smart Antenna Owner’s Manual
Surface Pressure
This feature displays pressure isobars and pressure centers. The isobars connect points of equal pressure. Pressure readings can help
determine weather and wind conditions in an area. High pressure areas are generally associated with fair weather. Low pressure
areas are generally associated with clouds and the chance of precipitation. Isobars that are packed closely together show a strong
pressure gradient. Strong pressure gradients are associated with areas of stronger winds. Pressure units can be displayed in Millibars
(mb), Inches of Mercury (in), and Hectopascals (hPa).
Strong Pressure Gradient
Pressure Isobars
XM W
eather
f
eatures
> s
urface
P
ressure