The rain that has caused minor flooding in some of the region’s rivers and creeks is supposed to continue for a few days, creating anxiety for Yakima Valley orchardists.

Forecasters expect a series of storms in the Pacific Ocean to push wet weather across South Central Washington through the weekend.

“Rainy on and off all through the week,” said Rob Brooks, a forecaster at the National Weather Service in Pendleton, Ore.

The rain, along with warmer temperatures, is hastening the snow melt in the Cascades, which in turn is causing rivers to rise.

The Naches River near Yakima is expected to rise slightly above its 16-foot flood stage by Saturday morning, according to a flood warning by the National Weather Service. The river reached 15 feet Thursday morning. Minor flooding was expected in the Rambler’s Park levee area, west of Yakima.

The areas of Cliffdell along the Naches River and Umtanum along the Yakima River were expected to see high water, though not high enough for a flood warning, Brooks said.

Also, authorities in Kittitas County have reported flooding on Naneum Creek and other streams east of Ellensburg.

More is possible in the Yakima River floodplain, according to hydrology forecasts. Kittitas County officials took the precautionary step of making sand available for bagging at the county fairgrounds parking lot.

The rest of April should bring “normal” weather, Brooks said, with temperatures around the historic average high of 64 degrees. However, that doesn’t stop farmers from fretting.

Temperatures will hit about 65 today, most likely a high for the whole weekend.

The damp, cool weather leaves fruit growers worried about a host of potential problems, including pollination, cold damage and the timing of the markets.

Bees placed in orchards to pollinate cherries, apples, peaches and apricots need at least 65 degrees to even leave their hives.

Warm, sunny weather late last week and early this week prodded blossoms out of their slumber a little earlier than expected. However, rainy, damp weather in California made for longer hours there for the nomadic bees, postponing their arrival in the Yakima Valley.

Dave Cowan placed bee boxes in his Grandview orchards Monday night, the evening before full bloom. He would have preferred to give the bees a few days’ head start.

“They couldn’t get there any later,” he said.

Meanwhile, an early bloom can be disastrous if freezing follows. A bud in full bloom will not tolerate temperatures below 32 degrees.

The weather service has not called for any such nights in early April, but in six out of the past eight years, Yakima has seen overnight lows of 20 degrees or lower by the middle of the month, Brooks said.

“This time of year, that would be devastating,” said Dennis Jones, an orchardist and vegetable grower in Zillah. “That would probably wipe everybody out.”

Growers dealt with a cold snap in late March, firing up wind machines, spraying water and lighting diesel heaters to protect their buds, which were still pretty new and more resistant to cold. The farmers have those tools ready to go again if needed, Jones said.

Most growers suspect that if they can make it until April 20 or so, they are generally safe. That’s when Jones begins planting vegetables, which are even less cold-hardy.

Also, overlapping markets are a concern to cherry farmers. Generally speaking, the bloom date sets the harvest date, said Mark Barrett, a fourth-generation orchardist from West Valley.

If California is late and the Yakima Valley is early, cherries from all over the West Coast could flood the market at one time, driving down prices and creating labor shortages. That’s looking very possible, Barrett said.

Even within the Valley, Grandview begins bloom and harvest a week or two earlier than Yakima, which growers prefer to stagger the demand for labor.

“It’s good to have it spread out,” Barrett said.

• Ross Courtney can be reached at 509-930-8798 or rcourtney@yakimaherald.com.