Today’s Poll

November was very, very wet

Nelson Daily Staff
By Nelson Daily Staff
December 5th, 2017

Precipitation dominated the month of November in the West Kootenay said Jesse Ellis Fire Weather Forecaster for the Southeast Fire Centre in the monthly synopsis.

Ellis said November started with a large accumulation of snow before mild Pacific flow took over to dominate the month with above-average temperatures and rain.

“Once the milder Pacific flow gained control by (November) 10th, it dominated through the rest of the month to maintain above-average temperatures most days with a prevailing valley wind direction out of the south,” Ellis explained.

“Rain became the dominant precipitation type with each successive Pacific frontal system that passed over the area after the 10th — of which there were many — for a total monthly rainfall of almost 70mm — 19% more than normal.” 

Ellis said November started out with a fairly active pattern as a moist Pacific flow advanced northeastward over a modified Arctic air mass that had pushed west of the Rockies.

He said this resulted in the first significant snowfall of the season and an accumulation of 15cm on the ground by the morning of the November 3rd, adding that is unusually early. 

“The modified Arctic air mass remained in the valley for more than a week thereafter, during which time temperatures remained below seasonal normal and the monthly minimum temperature of -5.8 degrees was seen shortly before sunrise on the morning of (November) 7th,” Ellis said.

“The only other snowfall event that brought more than 10cm in one go began on the night of (November) 8th, continuing into (November) 9th as a warm and moist southerly flow advanced over — and eventually scoured out — the cooler and denser air mass in the valley.”

Ellis said the mean monthly temperature of +2.5 was 0.4 degrees above normal with total snowfall was 5 per cent below normal.

He said the warmest temperature of the month was seen on the first, before the initial push of modified Arctic air made it into the area and while the sun angle was still relatively high.

Environment Canada is forecasting a dryer, cooler trend for the beginning of December with temperatures dipping just below zero under a mix of sun and cloudy skies.

That trend is expected to continue for most of the month with snow arriving later in December.

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