Thunder Bay In Sites for Winter Storm Conditions Tonight into Thursday

THUNDER BAY – WEATHER – The NetNewsLedger Weather Desk is tracking a developing winter storm for the City of Thunder Bay, with Environment Canada issuing a Yellow Winter Storm Watch as of early this morning.

While the impact level is listed as moderate, the combination of snow, strong winds, and a risk of freezing rain will be more than enough to disrupt travel and make conditions tricky on highways and city streets through Thursday night.

At 7:00 AM EST, Thunder Bay Airport is reporting cloudy skies and a temperature of –8.4°C, feeling closer to –15°Cwith the northwest wind at 17 km/h gusting to 28 km/h.

Humidity is sitting at 61 percent, visibility is a solid 24 kilometres, and the barometric pressure is 101.1 kPa and rising, a sign of the pattern shifting ahead of the incoming low. For mid December, a daytime high of around minus single digits is typical; the region has seen much colder and occasionally milder extremes on this date, although specific historical record highs and lows for December 17 are not included in this bulletin.

Tonight: Snow Moves In, 5 to 10 cm by Morning

Today, Thunder Bay will enjoy a relatively calm lead up to the storm with a mix of sun and cloud. Winds are expected to be west 20 km/h gusting to 40, becoming light early this afternoon as the high reaches about –4°C. The morning wind chill near –20°C will slowly ease to around –9°C by the afternoon, keeping it feeling properly wintry but manageable for errands, school runs, and outdoor work.

Tonight, things begin to change. Skies turn cloudy, with a 30 percent chance of flurries this evening before snow begins late this evening. By morning, 5 to 10 centimetres of fresh snow are expected. Winds will shift to the southeast at 20 km/h, gusting to 40 km/h, then become light after midnight. Temperatures will actually rise to around –1°C by morning, and the wind chill will hover near –10°C this evening and around –5°C overnight. The combination of new snow, slightly milder air, and increasing moisture will set the stage for a messy Thursday.

Thursday: Snow, Rain, Freezing Rain and Blowing Snow

Thursday is shaping up to be the main impact day for this system. Snow at times mixed with rain is in the forecast, and there is a risk of freezing rain late in the morning and through the afternoon, particularly for neighbourhoods closer to Lake Superior. That mix of precipitation means that while total snowfall amounts of 15 to 25 centimetres are possible for the event, some locations may see less snow if more of the day falls as rain or freezing rain.

Local blowing snow is expected late in the afternoon as winds strengthen. Winds will become north 20 km/h early in the afternoon, then increase to 40 km/h gusting to 60 km/h, drawing in colder air from the north. The high will briefly reach around +1°C, but temperatures will fall back toward –4°C in the afternoon. Wind chill will feel close to –5°C in the morning, then trend colder as the northerly winds take over.

Thursday night, the system transitions back fully to snow. The forecast calls for snow and local blowing snow, with windy conditions and a low near –21°C. As the temperature plummets, any wet and slushy surfaces from Thursday’s rain or freezing rain will freeze hard, and drifting snow will add to the cleanup challenge by Friday morning.

End of the Week: Staying Cold and Unsettled

On Friday, Thunder Bay will see a mix of sun and cloud with a 30 percent chance of snow and a high near –13°C, cool but more seasonal after the storm. Friday night stays unsettled with cloudy skies and a 60 percent chance of snow, and a low near –18°C.

The pattern remains wintry into the weekend. Saturday will be cloudy with a 40 percent chance of flurries and a high around –6°C, followed by cloudy periods Saturday night and another 40 percent chance of flurries, with a low near –20°C. Sunday brings a 30 percent chance of flurries and a high near –12°C, and Sunday night holds a 30 percent chance of snow with a low near –19°C.

Early next week, Monday carries a 40 percent chance of snow and a high near –6°C, then a continued chance of snow Monday night with a low near –13°C. By Tuesday, a mix of sun and cloud with a high around –9°C suggests a calmer, colder day as the region slowly recovers from the stormy stretch.

Travel, Safety and What to Wear

With 15 to 25 centimetres of snow possible, a period of rain or freezing rain, and strong northerly winds gusting up to 70 km/h on Thursday, roads and walkways around Thunder Bay will likely be slippery, rutted and hard to navigate. Visibility may drop suddenly to near zero in bursts of heavy snow and blowing snow, especially along exposed sections of the Thunder Bay Expressway, Highway 61, and rural routes out toward Kakabeka, Shuniah, and beyond.

If you can, it is wise to prepare for delays and possible disruptions to transportation, services and utilities. Charge devices, top up fuel, and make sure your vehicle’s winter kit is ready, with a blanket, booster cables, scraper, and emergency supplies.

For clothing, today calls for standard winter layers: a warm base layer, mid-layer like a sweater or fleece, and an insulated, windproof jacket. Boots with good grip are important, as the snow begins to fall tonight. On Thursday, with the mix of snow, wet snow, and possible freezing rain, a waterproof outer shell or parka with a good hood will help keep you dry. Combine that with snow pants or lined pants, a toque, neck warmer, and insulated mitts or gloves, and you will be far more comfortable waiting for buses, clearing driveways, or navigating icy parking lots.

Thunder Bay Weather Trivia – Lake Superior’s Wild Card

Thunder Bay’s position on the northwest shore of Lake Superior often turns winter storms into tricky forecasts. Slight shifts in the track of a low pressure system can determine whether the city sees mostly snow, a messy mix of snow and rain, or a glaze of freezing rain, especially when temperatures hover near the freezing mark like they will on Thursday. Lake Superior’s influence can sometimes cut snowfall totals near the shoreline while leaving inland areas buried, and it can also enhance winds and lake-effect bursts behind a passing system.

This upcoming storm is a textbook example of that Great Lakes wild card: a mix of snow, possible freezing rain, and strong northerly winds, all packed into a thirty-six hour window that will keep Thunder Bay drivers, plow crews, and travellers on their toes.

The Last Word:
Thunder Bay faces a winter storm watch with 15–25 cm of snow, strong north winds, blowing snow and possible freezing rain from tonight into Thursday night.