A special weather advisory warning of extreme cold — expected to ice up the entire region this week — follows a rather mild and sodden January.
Regarding the cold front, Environment Canada forecasts that an Arctic airmass will sweep through the West Kootenay over the next several days bringing with it, temperatures 10 to 20 degrees below the seasonal average.
The freeze is expected to persist all week, making for the coldest conditions experienced this winter.
The Arctic front follows three sets of Pacific storms in January, which resulted in a stronger than normal, mild westerly flow, contributing to a record-breaking amount of rain.
The monthly total of 85.6 millimetres (mm) of rain was over three times the average. Total snowfall was 61 per cent above average and total precipitation was more than double the average.
Maximum daily precipitation records were broken on Jan. 11 (18.4 mm), Jan. 12 (28.6 mm), and Jan. 31 (18.8 mm).
The number of days with measurable precipitation was not unusually high (17 days out of 31), so for total precipitation to be more than double the monthly average, some storms brushed in with much more moisture than is typically seen in January, explains local forecaster Jesse Ellis.
Ellis says some of the month’s frontal systems fed on moisture originating from sub-tropical latitudes of the central and eastern Pacific. A strong cold front associated with the frontal wave fed by an atmospheric river during the night of Jan. 12 and early morning hours of Jan. 13. This led to strong winds and (somewhat counter-intuitively) the warmest temperature of the month along the leading edge of the well-mixed post-frontal airmass.
Daily temperature records were broken on several occasions: Jan 2 (5.5 C) breaking the previous record of 4.8 C from 1977; Jan. 12 (9.6 C) breaking the previous 7.5 C record from 1980; and Jan. 13 (8.0 C) ending the previous record of 7.3 C from 2014.
The month’s maximum temperature of 9.6 C came within a half degree of the monthly record of 10 C, set in January 1974.
The mean monthly temperature of -0.1 C was 1.5 degrees above average.
The coldest temperatures of the month were recorded during the morning hours of Jan. 23 (-9 C) and Jan. 24 (-10.4 C) as a result of overnight cooling under clear or partly clear skies and a relatively dry north-northwesterly flow aloft.
Read more: Up to date weather for Trail