Nurses ended their two-day strike at Memorial Hospital at 5 a.m. today but vowed to continue picketing outside the Santa Rosa hospital until they are allowed to return to their jobs over the weekend.

About 150 temporary nurses hired to keep the hospital operating during the strike will continue to work until Saturday morning, when their four-day contract expires, said Debra Miller, vice president of human resources for St. Joseph Health System in Sonoma County, which operates Memorial.

A handful of union nurses will return to work this morning, when the hospital reopens an outpatient surgery center in Santa Rosa and urgent care centers in Windsor and Rohnert Park.

Sue Gadbois, president of the 660-member Staff Nurses Association, said management had been notified in advance that the picketing would continue if nurses were unable to return to work after the scheduled two-day strike.

"We told them that if we were to be locked out we'd be out here doing informational picketing," Gadbois said.

The nurses said they went on strike to repel a number of "take-aways," including proposed reductions in night shift pay and on-call pay. The two sides also disagree on a wage increase.

The hospital proposes a 1 percent increase beginning in 2013 and another 1 percent increase in 2014, while the union wants a 5 percent increase beginning this month and another 5 percent increase next year.

The union said the desired increase would keep nurse wages competitive with other Bay Area hospitals, and that the hospital posted a record $38 million operating margin — the difference between revenue and costs — for the fiscal year ending June 30.

But hospital officials argue that its operating margins are just large enough to allow the hospital to reinvest in new technology and other infrastructure. Also, hospital officials said they must plan for reduced government payments with the full implementation of President Obama's health care overhaul.

The hospital hopes to resume negotiations with the Staff Nurses Association soon, Miller said.

"We are hopeful that we will be back in negotiations with SNA shortly after the end of this week," Miller said.

On Wednesday, dozens of nurses once again picketed up and down Montgomery Drive in front of Memorial Hospital. Donuts, coffee, cooler weather and, of course, the ubiquitous sound of car horns made for a celebratory atmosphere.

Nurses from different departments mingled and got to know each other on the picket line.

"Nurses have come together," Gadbois said. "We want to impress on hospital administration that we're serious about our issues and in fact, we are so serious that we're willing to go without pay in support of those issues."

Two of the three urgent care centers operated by St. Joseph Health, in Rohnert Park and Windsor, will reopen today. The ambulatory surgery center, an outpatient facility in Santa Rosa, will also reopen today.

In all, 10 to 12 nurses will return to work today. The union said there are only about two to three nurses who work at the urgent care center at any given time, so the majority of union nurses will not return to work until 7 a.m. Saturday, the end of the last shift for replacement nurses.

(You can reach Staff Writer Martin Espinoza at 521-5213 or martin.espinoza@pressdemocrat.com)