CAPE CANAVERAL, Fla. -- NASA will make a run at landing shuttle Endeavour in Florida on Monday but bad weather is forecast for the Sunshine State.

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Rainshowers are expected over the Kennedy Space Center (KSC) when the shuttle is to land at 12:59 p.m. EDT (1659 GMT), and thunderstorms are predicted 90 minutes later for the second and final landing opportunity of the day.

"The weather outlook is poor," NASA flight director John Shannon said Sunday. "We'll just show up tomorrow and hope we get a little bit lucky."

Dense moisture streaming Sunday from the Yucatan Peninsula and a line of severe thunderstorms over Texas are expected to meet up in the Gulf of Mexico overnight and become the principal weather concern for Florida, Shannon said.

The state's typical summer pattern of afternoon thunderstorms triggered by the ocean sea breaze won't help matters.

Not to worry, as weather at the backup landing site at Edwards Air Force Base in California is forecast to be nearly ideal all week and the shuttle has enough supplies to safely remain in space until Thursday, Shannon said.

So if Endeavour can't land on Monday and the weather forecasts don't become more optimistic, it's very possible the spaceplane and its seven-member crew will wind up remaining in orbit until Wednesday.

That's the day Endeavour would come home to Florida or California, whichever site was acceptable first, Shannon said.

NASA's philosophy on landing shuttles is to do everything safely possible to end a mission in Florida and avoid the increased cost and risk of having to load an orbiter atop a 747 jumbo jet and ferry the duo cross country.

Endeavour's next mission, planned for launch Oct. 6, could be delayed as well.

Key events to watch for on Monday start about 9:10 a.m. EDT (1310 GMT) when the crew will be ordered to close Endeavour's payload bay doors, and then about 11:30 a.m. (1530 GMT) when Mission Control is scheduled to give a "go" for landing.

Of course, depending on what the weather is doing, a decision on committing the shuttle to a landing or extending the flight could come at anytime during the morning.

If the weather cooperates, astronauts would start up Endeavour's braking rockets at 11:51 a.m. EDT (1551 GMT) for a 12:59 p.m. EDT (1659 GMT) touchdown.

The second chance for a KSC homecoming on Monday calls for the shuttle to de-orbit at 1:30 p.m. EDT (1730 GMT) and land at 2:36 p.m. EDT (1836 GMT).

Meanwhile, it was a relatively quiet Father's Day in space, with the Endeavour crew enjoying a half-day off after completing a series of routine, day-before-landing checks of the shuttle's systems and maneuvering engines -- all of which went well, Shannon said.

On a day when many families celebrated their patriarch by spending time together, the returning Expedition Four station crew remained far from their loved ones, as they have for the past 193 days.

U.S. astronauts Dan Bursch and Carl Walz -- who together now hold the American spaceflight endurance record -- and Russian cosmonaut Yuri Onufrienko have nine children among them.

Their families are waiting for them in Florida, so the prospect of being diverted to California and a delay in the subsequent reunion isn't very appealing, they said Sunday.

"The best Father's Day gift we can get would be an on time landing at Kennedy Space Center," Walz said. "I'm just really looking forward to seeing their faces."

Wherever Endeavour winds up landing, and when, Shannon said a full complement of medical specialists will be on hand to assist the long duration space voyagers to begin their re-acclimation to life on Earth.