British Columbia

Wagstaffe's Weather Friday: Dry May to break low rainfall records

A few high clouds this morning will quickly give way to another summer-like day with lots of blue skies, as many parts of B.C. line up to shatter records for record low rainfall this month.

Dry weather records are expected to tumble from Victoria to Prince Rupert this month

There were just a few clouds in the sky north of Maple Ridge, Friday morning. (Rafferty Baker/CBC)

A few high clouds this morning will quickly give way to another summer-like day with lots of blue skies, as many parts of B.C. line up to shatter records for low rainfall this month.

Lingering moisture in the air will make it feel like the mid-20s on Friday afternoon. Temperatures will come down slightly for the weekend, but it will be warm and sunny through to Sunday night.

With no rain in the forecast, YVR is on the verge of setting the bar for driest May seen since records began in 1937.

Only 4.2 millimetres fell at YVR, where the records are taken. YVR usually gets around 65 millimetres of rain for May — meaning we saw just 6.5 per cent of our monthly rainfall. 

  Victoria is also on the verge of an all-time driest May. Its airport station saw just two millimetres in a month that normally gets about 37 millimetres.

The contrast is even more stark for places like Prince Rupert where only 3.3 millimetres fell this month, compared with the May average of 138 millimetres. 

What's causing the dry weather?

The dry weather comes along with record low snowpacks left over from a warm winter in B.C., and ahead of long range forecasts for a hot, dry summer.

Experts say an unusually strong high pressure system that has remained anchored offshore of the Pacific Northwest for months is causing the dry weather.

This ridge of higher pressure essentially protects the West Coast from approaching Pacific storms, and brings in warmer temperatures too.

As for how the high pressure system got so strong, warmer than normal sea surface temperatures — nicknamed 'The Blob' — have been observed in the North Pacific Ocean for the past couple of years.

An El Nino system this summer is expected to keep these conditions locked in. 

This is all great news for those who have been enjoying the summer-like weather this spring, but the consequences are could be severe for the environment.

After a early start to the wildfire season, dry weather, low snowpacks in the mountains and low river levels will likely lead to severe impacts on ecological systems in the months to come.


Johanna Wagstaffe

Senior Meteorologist

Johanna Wagstaffe is a senior meteorologist for CBC, covering weather and science stories, with a background in seismology and earth science. Her weekly segment, Science Smart, answers viewers' science-related questions.


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