NetNewsLedger Weather Desk – Thunder Bay Outlook

THUNDER BAY – WEATHER – Thunder Bay is waking up under cloudy skies and a slick setup for Tuesday, as an Alberta clipper brings an icy mix this morning before temperatures jump above freezing and then slide back into snow and deep cold later this week.

While the city remains under a Special Weather Statement, the expected precipitation that was forecast for overnight has not happened – Yet!

At 5:00 AM EST, conditions at Thunder Bay Airport were cloudy with a temperature of –12.3°C, feeling like –14°Cwith a light southwest wind at 3 km/h. The humidity sits at 85 percent, with a dew point of –14.3°C, and visibility is about 19 kilometres through the early morning cloud.

The barometric pressure is 100.8 kPa and falling, a good signal that our weather is in transition.

For mid-December along the north shore of Lake Superior, daytime highs often land in the minus single digits and overnight lows drop into the minus teens. While specific record highs and lows for December 16 aren’t included in this report, today’s conditions fit right into a typical Thunder Bay December – just with a little extra drama from ice pellets and possible freezing rain.

Special Weather Statement: Icy Conditions Possible

Environment Canada continues to highlight the risk of patchy ice pellets and freezing drizzle as part of a Special Weather Statement for the City of Thunder Bay.

Hazards:

• Patchy ice pellets or freezing drizzle

• Light ice accretion leading to hazardous travel conditions

An Alberta clipper moving across Northwestern Ontario is drawing in warmer air aloft over cold surface temperatures. That setup is ideal for mixed precipitation, including ice pellets and localized freezing rain, especially this morning. Even a thin glaze of ice can make roads, sidewalks, and steps very slippery, so caution is advised for anyone out early.

Today: Icy Start, Then a Mild +3°C

For today (Tuesday), expect mainly cloudy skies with a 60 percent chance of ice pellets early this morning along with a risk of freezing rain. Winds will increase, becoming southwest near 20 km/h this morning, ushering in milder air.

The high is forecast to reach around +3°C, which will feel like quite a change compared to this morning’s –12°C start. However, the wind chill early on will still feel near –14°C, and the combination of ice pellets, a bit of freezing rain, and warming temperatures means slushy, rutted, and icy conditions on many roads and walkways.

If you’re driving on Highway 11/17, neighbourhood streets, or walking to school or work, watch for:

• Black ice at intersections, bridges and overpasses

• Slush and puddles that can hide underlying ice

• Very slick sidewalks, driveways and bus stops

Tonight: Showers Turning to Flurries as Temperatures Drop

Tonight remains cloudy with a 40 percent chance of rain showers this evening, changing over to a 40 percent chance of flurries overnight as colder air returns.

Winds will swing northwest 40 km/h gusting to 70 km/h this evening, then ease back to a west wind near 20 km/hbefore morning. The low will drop to around –12°C, and the wind chill will feel closer to –16°C overnight.

Any water or slush left on roads and sidewalks from the daytime thaw is likely to refreeze, setting up icy patches again by Wednesday morning.

Wednesday: Bright but Cold, Snow Moving In at Night

On Wednesday, Thunder Bay gets a brighter day, with mainly sunny skies and a high near –5°C. Winds will be light, up to 15 km/h, but it will still feel crisp: the wind chill will be around –18°C in the morning and near –8°C in the afternoon.

Clouds increase late in the afternoon, and periods of snow are expected to develop Wednesday night with a low near –5°C. That will lay the groundwork for a more wintry Thursday.

Thursday: Snow, Local Blowing Snow, Then a Deep Freeze

Thursday brings a return to full-on winter. Expect periods of snow with local blowing snow and windy conditions, with a high near –7°C. The fresh snow and strong winds will reduce visibility at times and lead to drifting along open stretches of highway and in exposed neighbourhoods.

Thursday night, skies turn to cloudy periods with a 40 percent chance of flurries, and temperatures plunge to a low near –24°C. It will be a harsh return to deep cold, with wind chills likely pushing well into the minus twenties and a renewed risk of frostbite on exposed skin.

Beyond that, the pattern stays wintry:

• Friday: 30 percent chance of flurries, high near –10°C; periods of snow Friday night with a low near –9°C.

• Saturday: 40 percent chance of flurries, high near –10°C, then clear skies Saturday night with a low near –18°C.

• Sunday: A mix of sun and cloud with a high around –11°C, followed by a cloudy Sunday night with a low near –15°C.

• Monday: Another mix of sun and cloud with a high near –10°C.

What to Wear Around Thunder Bay

This is a layer-up kind of week, especially with a slippery start and deep cold returning by Thursday night.

Today and tonight:

• Start with a thermal or fleece base layer on top and bottom.

• Add a warm mid-layer, such as a hoodie or sweater.

• Top it with a good insulated winter jacket that blocks wind and sheds wet snow or drizzle.

• For your legs, lined pants or snow pants are wise if you’re spending time outside or walking longer distances.

On your feet, insulated winter boots with solid tread and thick socks are essential. With ice pellets, possible freezing rain and refreezing, traction is just as important as warmth. A toque, warm mitts and a scarf or neck warmer you can pull over your mouth and nose will help with both wind chill and the damp feel of mixed precipitation.

Thunder Bay Weather Trivia – From Ice to Deep Cold in 48 Hours

Thunder Bay sits in a crossroads zone where Alberta clippers, Arctic air, and Lake Superior moisture all meet. That’s why the city can swing from –12°C and icy pellets to +3°C with rain, and then back to snow, blowing snow and –20s wind chill in just a couple of days.

This week is a perfect example of that roller-coaster: icy now, mild briefly, then straight back into a deep freeze. It keeps drivers, walkers, and plow crews on their toes – and makes checking the forecast part of daily life along the north shore.

Last Word on the Weather:
Thunder Bay faces icy pellets and freezing rain risk this morning with a high of +3°C, then sunshine Wednesday, snow Thursday and a sharp plunge to –24°C Thursday night.