Column: More hot, dry weather to come, climatologist says

A hot dry summer this year followed by an El Nino event in the winter could threaten water supply issues in coming years.

We may see some relief from the heat this coming weekend but according to Environment Canada and the National Oceanic and Atmospheric Administration (NOAA), temperatures will remain above normal for the next month and probably into the fall. And, according to NOAA, we could be getting less rain than normal. So far, July has continued the trend of record-breaking heat waves.

“On July 13, a maximum record of 34.5 degrees Celsius occurred,” said Roger Pannett, volunteer weather observer for Environment Canada. “The average for the day is 24.2 degrees Celsius. The previous record for that day was 33.9 degrees Celsius in 1961. After exceeding the record 34.3 degrees Celsius on July 1, July 13 was the hottest day in Chilliwack since the record-breaking 36.0 degrees Celsius on August 14, 2010. The all-time Chilliwack maximum record of 38.2 degrees Celsius occurred on July 29, 2009, the second day of a three-day heat wave that year.”

Pannett said that to date, this month’s temperatures have been two to seven degrees Celsius above normal. As for precipitation, as at July 16 we’ve only had 2.4 mm rain, on track to possibly match last year’s July precipitation at 5.0 mm.

“The average July rainfall is 46 mm on six days,” said Pannett, adding that Chilliwack weather records were started in 1881.

Over half of the province has been under the hot spell due partly to really hot air being pumped from the southwestern United States under a strong high ridge. All this heat and dryness spurred an air quality advisory for the Fraser Valley due to high concentrations of ground-level ozone that have persisted for several days.

Then of course, there are wildfires and from April 1 to July 16 there have been 564. The 10-year average taken from 2003 to 2012 is 1,908 fires, 38.6 per cent caused by people and 61.4 per cent caused by lightning with 2009 having the most number of wild fires at 3,064. Smoke from wildfires blazing in NWT and northern Alberta is already clouding the skies in northeastern U.S.A.

This weekend though might bring some relief with a bit of rain.

“The situation now is the high ridge in western Canada and it’s not going to go away,” said David Phillips, senior climatologist with Environment Canada. “There will be some precipitation this weekend but not much. This is the dry season. Our models show that what you see is what you are going to get. Early spring we predicted it would be a warmer than normal summer. There has also been so little precipitation. What we are showing is that, after a little change this weekend, later next week and into August it’s going to be dryer and warmer. It’s as though you are not getting enough weather. You should be getting precipitation but it’s down and continues to stay down. What are different are the warmer temperatures.”

Phillips said that they are fairly sure an El Nino event will materialize 60 per cent in August and 80 to 90 per cent in late fall and early winter. According to NOAA, during June this year above-average sea surface temperatures were prominent in the eastern equatorial Pacific although there has been some weakening since.

It is the warm sea surface temperatures that influence the El Nino current bringing worldwide weather changes. Phillips warned that a hot dry summer this year followed by an El Nino event in the winter could threaten water supply issues in coming years.

“A year from now if El Nino materializes you could be into a bit of a water shortage,” said Phillips. “The atmosphere will suck up any moisture which could interfere with water supply and power production.”