The Dow .DJI and the S&P 500 .SPX closed out their best first quarter since 1998 and the Nasdaq .IXIC had its best first-quarter performance since 1991, largely on the back of improving domestic economic data.

Economic indicators next week include data on manufacturing and services from the Institute for Supply Management, construction spending, factory orders and domestic car sales as well as several reports on the labor market, culminating in Friday's payrolls number.

The benchmark S&P 500 index could be vulnerable to a retreat if the data shows a softening of the economy, a possibility many investors have been cautiously eyeing with the index up nearly 30 percent from its October low.

"The remarkable part of the first quarter is you really didn't have any major piece of economic data in the U.S. that disappointed the market," said Dean Junkans, chief investment officer of Wells Fargo Advisors and Wells Fargo Private Bank in Minneapolis.

"It was really a no drama, no surprise quarter and the market may not be fully appreciating that we could have some surprises here in some of the data coming up."

MARCH JOBS AND FED MINUTES

Equity markets will be closed at the end of the week for the Good Friday holiday, which could create lighter volume and increase volatility. The holiday also conflicts with the release of the March payrolls report, which could leave investors reticent to make big bets in front of the data.

Economists polled by Reuters are looking for an addition of 201,000 jobs in March, compared with February's 227,000. They expect the U.S. unemployment rate to remain steady at 8.3 percent.

"People are looking for a little more out of the data, but it ultimately depends on how the numbers come in relative to expectations - it's all about beating or missing expectations," said Joseph Tanious, market strategist at J.P. Morgan Funds in New York.

"That will likely dictate the market the following Monday after Good Friday."

Along with dealing with a short week and a glut of economic data, investors will have to grapple with Tuesday's release of the minutes from the most recent Federal Open Market Committee meeting and an interest-rate decision on Wednesday by the European Central Bank after its meeting.

"The underlying issue in Europe - the sovereigns themselves being solvent - has not been resolved," Tanious said. "I would suspect you will continue to see some flare-ups in Europe that will rattle markets here in the U.S."

The ECB is expected to keep interest rates unchanged with no major announcements on other policy decisions while the Fed minutes will not be followed up with a press briefing by U.S. Federal Reserve Chairman Ben Bernanke.

Comments from Bernanke signaling a supportive monetary policy on Monday lifted stocks more than 1 percent and helped boost the index higher for the week despite three consecutive sessions of declines. Investors will look to the FOMC minutes for any change in language.

WARMING UP FOR EARNINGS SEASON

The earnings calendar is light, with Monsanto Co (MON.N) and Constellation Brands Inc (STZ.N) the only S&P 500 companies due to release results. Investors will be gearing up for the unofficial start of earnings season the following week, when Alcoa Inc (AA.N)> reports on April 10.

Also on tap are same-store sales from retailers on Thursday, which could give further insight on consumer habits on the heels of Friday's consumer sentiment and personal income and spending data.

"You've got manufacturing, service, retail and jobs all coming out during the week, plus you are going to have people next week start to think about first-quarter earnings," Junkans said.

But even if equities do pull back - and with more than 80 percent of the benchmark S&P 500 above the 200-day moving average - the market would appear primed for one, analysts cautioned it was more likely to be a healthy decline.

"If you get weakness initially in April, no one is going to really panic unless all of a sudden, the bottom falls out," said Ken Polcari, managing director of ICAP Equities in New York.

"But I don't suspect that is going to happen because I still believe we are the prettiest girl on the block and that if the market gets weak, there is still plenty of money to be put to work."

(Wall St Week Ahead runs every Friday. Questions or comments on this column can be emailed to: charles.mikolajczak(at)thomsonreuters.com)

(Reporting by Chuck Mikolajczak; Editing by Jan Paschal)

• A Permanent Economic Emergency