Sonoma State's School of Education has been fielding so many requests to post teaching openings this spring that for the first time in more than a decade it hosted a job fair where school districts from across Northern California handed out fliers and advertised what seemed unthinkable just a few years ago: "We're hiring."

More than 100 prospective candidates moved from table to table Friday at the campus in Rohnert Park, handing out resumes and talking about job openings with representatives from more than 25 school districts Friday afternoon.

"It's always hard to get a job as a teacher, but I'm hopeful," said Sonoma State graduate Antonella Leone. "I feel better having been here. It makes me more confident I will get a job."

Industry watchers say that confidence is not misplaced.

The sea change in job opportunities is a combination of more predictable budgets with the passage of Proposition 30 and forecasts of thousands of retirements in coming years.

"Local education is one that has seen some good growth in government," said Rob Eyler of the university's Center for Regional Economic Analysis. "Prop 30 passing probably jumped a lot of jobs back in the pipeline."

More than 36 percent of Sonoma County's educators are 55 years old or older — the highest percentage among the eight industries studied by the Sonoma County Economic Development Board.

"It's unprecedented," said Ben Stone, executive director of the Sonoma County Economic Development Board. "It's an age wave we are facing. That silver tsunami is coming at us in terms of education."

Friday's fair comes on the heels of a steep downturn in the number of annual teacher layoff warnings.

The total number of so-called pink slips issued in Sonoma County by the March 15 deadline are down by more than half from four years ago. Only Windsor School District issued a significant number of layoff warnings — for 47 full time positions — which accounted for well over half of those issued across the county's 40 school districts this spring.

And Windsor officials said they expect their final cut to be nearer to 23 full time positions.

But more than increased budget stability, it's the aging work force that presents the most dramatic potential change in the teaching ranks in the coming years.

Mendocino County officials saw a surge in new hires this year, according to Karen Ricketts, interim regional director of the Sonoma County Office of Education Beginning Teacher Program.

"They were expecting 60 new teachers and they have over 140," she said. "They had unexpected retirements and they also had people leaving the area."

Ukiah School District had 21 retirees this year, up from an average of eight or nine, according to Troy Sherman, assistant superintendent of human resources.

The trend is likely to hold, he said.

"Currently we have more than 100 teachers who are 55 or above," he said. "So it's going to be significant difference over the next five to 10 years."

Petaluma City Schools was not among the 25 school districts at Friday's job fair, but Superintendent Steve Bolman said the district is focused on adding back eight days to the school calendar next year and eventually examining reducing class sizes, which would require more teachers.

Jordan West of Bodega Bay wants to be ready. The Sonoma State student does not expect to graduate until the spring of 2014 but he was at Friday's fair learning more about the local job market.

"I'm jumping the gun a little bit," he said. "I'm just trying to build a bigger idea of what I need to do 12 months from now so I can get myself hired."

(Staff Writer Kerry Benefield writes an education blog at extracredit.blogs.pressdemocrat.com. She can be reached at 526-8671, kerry.benefield@press democrat.com or on Twitter @benefield.)