There’s a good reason you likely broke out the winter jacket a few weeks early in October.
The Southeast Fire Centre’s monthly weather summary says we broke a cold record last month.
“The mean monthly temperature — that is, the average temperature when you take all the high and low temperatures and average them out — was 2.1 degrees cooler than the record,” says forecaster Jesse Ellis. “So that was a new record low. It was 5.9C. Previously the record was 6.1, set in 2009.”
A northwesterly or northerly flow aloft that dominated much of October helped bring cooler and drier than average conditions to the area.
“The main driver for our weather in October is we had an upper ridge over the Pacific, and a deep upper trough over eastern North America,” he says. “That put us in a northwesterly flow. And not only is a northwesterly flow cooler, but it allows interesting things to happen at the surface… it allows high pressure Arctic air masses to take little jaunts south down into southern B.C.”
Those “jaunts” turned into the feel of an early winter for residents of the West Kootenay’s mountain valleys.
The month’s peak temperature (17.4 degrees) that occurred under mainly sunny skies on the afternoon of Oct. 6 fell well short of the monthly record of 27.2 degrees set in 1980.
Not only was it colder, but drier, as almost all the rain fell during two separate events: the first was from Oct. 4 to 7, while the second was from the 16th to the 21st as two sets of Pacific frontal systems passed over the area.
Total rainfall was 38 per cent below average.
A fairly intense cold front that pushed eastward over southern B.C. on Oct. 25 brought strong gusty winds and highly variable precipitation. Convective cells embedded within the front (that were responsible for some of the more intense weather seen in many places that day) skirted just north and south of the area, with winds peaking just under 40km/h and only 0.8mm of rain locally.
A modified Arctic front that approached from the northeast on Oct. 28 brought cold gusty winds and a few (non-accumulating) snowflakes. Temperatures within the cool and dry airmass that followed dropped to -9.4C under clear skies the following night, breaking the daily record previously set in 1971. However, it still fell short short of the monthly record of -11.3C.
November should see the modified Arctic air mass stick around for this week, says Ellis. By mid-month we’ll start seeing more Pacific air masses moving this way, bringing more moderate temperatures — but also likely more precipitation. But of course, predictions are shakier as forecasters project farther into the future.
Your winter coat isn’t going to be put away anytime soon.