Orchards need warmer days, though might cause flooding

Weather in the next month or so will be a critical factor in determining whether we can expect flooding this spring, due to the deep snow that’s accumulated in the hills around this valley.

Weather in the next month or so will be a critical factor in determining whether we can expect flooding this spring, due to the deep snow that’s accumulated in the hills around this valley.

Because it’s been such a cold spring, little of the snow that fell all winter has melted yet and even more has been added to it in the last month or so.

Meteorologist David Jones with Environment Canada says this past month has been among the coldest five on record, due to a combination of the effects of La Nina and the Pacific Decadel Oscillation.

While La Nina results in colder than normal temperatures in the Pacific Ocean and causes colder and wetter than normal weather in this part of the world, the PDO is a pattern of Pacific climate variability that also can result in cooler surface waters in the Pacific, translating into cooler inland temperatures.

Jones said the result of a lower freezing level has been a snowpack that is still accumulating instead of melting as it normally would at this time of year.

Temperatures were about two degrees lower than normal during April, with an average mean temperature of 6.3 C, compared to the normal of 8.5 C.

Up until April 22, the high temperature for the month was only 14 C, he noted.

However, he says La Nina never persists through summer.

Dave Campbell, head of the River Forecast Centre for the province, says while they haven’t yet analyzed data from the snowpack measurements done around May 1, he does anticipate there could be as much as 20 per cent more than the normal amount of snow in local watersheds for the time of year.

How it will melt off depends on weather conditions in the coming six weeks or so.

The colder, wetter weather that is a feature of La Nina continues this spring, leading to concerns that all that snow could melt suddenly when it does warm up finally. Jones forecasts it will remain cool for the next while—a forecast that isn’t encouraging for orchardists.

Joe Sardinha, president of the B.C. Fruit Growers’ Association, says he hasn’t heard of any major problems in valley orchards caused by the cold weather yet, but some cherry growers have been using their wind machines to prevent damage from frost.

Cherries have begun to bloom, and many of the soft fruits such as apricots and peaches are nearly finished.

In the southern part of the valley, apples are getting close to what is called the pink stage of the bud.

It’s a point at which the blossoms are susceptible to low temperatures.

In addition, bee flight is delayed if the weather is cool during blossom, and some fruit trees depend on bees for pollination.

Even those varieties that are self-fertile benefit from bee activity, he said.

A consistent patch of warmer weather is needed at this time of year in order for this year’s crop to get off to the best start, said Sardinha.

jsteeves@kelownacapnews.com

 

 

Kelowna Capital News