When it snowed in December, it dumped in December.
While there were two significant snowfall “events” last month – the first was over four days beginning Dec. 19, and the other over four days ending on Dec. 30 – the overall precipitation was only 78 per cent the norm.
In other words, even with all that snow, it was drier than normal in December 2017.
The month’s mix of snow and rain typically amounts to about 90 centimetres, but only 70 cm of precipitation was measurable by Dec. 31.
“A Pacific system pushed across southern B.C. for periods of rain and snow during the initial two days of the month,” local forecaster Ron Lakeman noted in his Jan. 1 media release.
A series of systems produced more frequent snow the night of Dec. 14 through to the night of Dec. 19 and again the 27th through to the morning of Dec. 30, he stated.
“The most significant system dumped 30 cm of snow on Dec. 19 … another 23.6 cm fell between the 27th and the 30th.”
The slightly drier than normal climate was accompanied by a slightly cooler than normal mean (average ) temperature.
“A strong upper ridge of high pressure dominated for 12 days of persistent valley cloud and near seasonal temperatures from Dec. 3 through Dec. 14,” Lakeman said.
“A modified Arctic air mass pushed across southeastern B.C. for cooler/below freezing temperatures during the final 11 days of the month.”
Lakeman says the mean monthly temperature for December is usually -2.1 C, but last month it dipped a half degree to -2.6 C. The coldest day was – 12 C, recorded on Christmas Eve.
Interestingly, the coldest December day on record, at least locally, happened 50 years ago. According to Lakeman’s data, Christmas Eve 1968 was the most frigid night to date, when the mercury dipped to -30.6 C.
The overall coldest December in local records was back in 1979, when the average monthly temperature was -6.5 C.
The warmest December day last year was 4.4 C on Dec. 3.
That doesn’t near the warmest day in local records, which was 12 C on Dec. 27, 1980.