VANDENBERG AIR FORCE BASE, Calif. >> An advanced U.S. weather satellite designed to improve the accuracy of extended forecasts has been launched into polar orbit from California.

The Joint Polar Satellite System-1 lifted off from Vandenberg Air Force Base at 1:47 a.m. PST Saturday atop a United Launch Alliance Delta 2 rocket.

The satellite is the first of four next-generation spacecraft for NASA and the National Oceanic and Atmospheric Administration.

Circling the Earth from pole to pole 14 times a day, JPSS-1 carries a suite of five instruments intended to make global observations that will improve forecasts of severe weather events three to seven days beforehand.

The satellite also will contribute to near-term weather forecasts, climate and ocean dynamics research, among many other uses.