WxWorx, a weather data processing service, produces the various XM weather data, including some particularly interesting and useful displays for mariners such as storm-cell depiction. This mode shows the latest position of a radar-detected storm cell, its relative size and its projected path at 15-minute intervals. This picture, combined with ground-lightning-strike data, can be really useful when "getting out of Dodge" is the prudent thing to do. Sea-surface wind speed and direction information is depicted in the same format used on pilot charts. Atmospheric pressure is depicted as isobars with a similar format used to show surface visibility. Of primary use for long-range planning, and to better understand what will happen in the cruising days just ahead, the "Fronts" option includes the position and nature of highs, lows and all fronts regionally or for the entire continent. Sea-surface data obtained from satellite, buoy and ship reports, combined with computer models of the ocean, yield surface temperature of the water, wave height, wave period and wave direction information.