Garmin GDL 30A Owner's Manual - Page 15

XM WX Weather Features Pressure The pressure feature displays pressure isobars and pressure centers on the map. 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 (mbar), inches of mercury (in Hg), and hectopascals (hPa). See the chartplotter Owner's Manual for more information on configuring units of measure. Pressure Isobars Strong Pressure Gradient GDL 30A Owner's Manual 13