NATIONAL BRIEFING / FLORIDA

Thunderstorms threaten to delay NASA’s planned launch tonight of the space shuttle Endeavour, already a month late.

Endeavour is back for a third launch attempt after hydrogen gas leaks were repaired. But forecasters say there is a 60% chance that storms could force a postponement.

The shuttle is set to install the third and final piece of Japan’s $1-billion lab.

NASA has until Tuesday or possibly Wednesday to send up Endeavour before making way for the launch of an unmanned Russian supply ship. If that happened, the shuttle flight would be off until late July.