Widespread heavy rain, powerful winds, and rapid cooling mark the arrival of a significant fall storm across the region
THUNDER BAY – WEATHER – A strong low-pressure system pushing across Northwestern Ontario on Sunday, will bring heavy rain, embedded thunderstorms, and damaging winds to both remote and highway-accessible communities.
The storm will affect a broad area — from Kenora, Dryden, and Vermilion Bay eastward through Sioux Lookout, Pickle Lake, Cat Lake, Marten Falls (Ogoki Post), Lansdowne House (Neskantaga), and Sandy Lake — causing flooding concerns, power outages, and hazardous travel conditions.
🌧️ Rainfall Totals and Flooding Risk
Environment Canada has issued Rainfall Warnings for many locations, including Kenora, Dryden, Sioux Lookout, and surrounding First Nations communities. Rainfall totals of 50 to 75 mm are likely, with isolated areas exceeding 75 mm where multiple thunderstorms will track over the same region. Communities like Pickle Lake, Lansdowne House, and Cat Lake with extended periods of steady and intense rain, while Sandy Lake and Marten Falls will be impacted by localized downpours and rising creeks and waterways.
⚠️ Flash flooding, water pooling, and washouts near rivers and culverts are expected. Residents in flood-prone areas are advised to monitor local conditions, especially in low-lying terrain and near waterways.
💨 High-Impact Winds
A Special Weather Statement is in effect for much of the region as winds will increase sharply Sunday afternoon. Southwest gusts of 70 to 90 km/h were reported in open and exposed areas, including parts of Kenora, Sioux Lookout, and Dryden. In isolated thunderstorms, wind gusts will likely exceeded 90 km/h, potentially contributing to power outages, downed tree limbs, and localized infrastructure damage.
Remote communities such as Marten Falls, Lansdowne House, and Cat Lake also will experience strong wind gusts and turbulent flying conditions, prompting caution for bush pilots and remote medical flights.
🌡️ Temperature Crash and Cold Front Passage
Before the front passes, temperatures surged to 25°C in Thunder Bay, 18°C in Dryden, and 16°C in Kenora, with humidex values reaching 28–30 in southern portions of the region. However, by late Sunday night, colder air swept in behind the system, driving temperatures down to the low single digits — with further cooling expected into Monday and Tuesday.
Community Impact Snapshot
| Community | Rain/Wind Highlights | Notable Conditions |
|---|---|---|
| Kenora | 50+ mm rain, gusts to 80 km/h | Localized flooding and brief power flickers |
| Dryden & Vermilion Bay | 60+ mm rain, gusty winds | Ponding on roads and strong crosswinds |
| Sioux Lookout | Multiple showers & thunderstorms | Rain totals approaching 70 mm |
| Pickle Lake | Persistent heavy rain | Limited road visibility, saturated ground |
| Cat Lake | Thunderstorm activity | Potential washouts near creeks |
| Marten Falls (Ogoki Post) | Rain + strong wind shift | River level concerns reported |
| Lansdowne House (Neskantaga) | Prolonged rainfall | Isolated infrastructure stress |
| Sandy Lake | Stormy with embedded cells | Potential flash flooding risk |
| Thunder Bay | Winds near 70 km/h, 25°C → 8°C drop | Rapid temperature drop, windy evening |
⚠️ Key Hazards Recap
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Rainfall Totals: 50–75+ mm
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Wind Gusts: 70–90 km/h, higher near storms
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Risks: Flash flooding, power outages, tree damage, dangerous travel
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Temperature Trend: Warm and humid Sunday → much cooler and unsettled Monday
As of Sunday evening, the storm system was exiting into northern Ontario and Manitoba, with conditions expected to stabilize slowly into Monday. However, cooler air, cloudy skies, and spotty showers will remain in place across the region to start the workweek. Frost risks return by Tuesday night in many communities, including Dryden, Sioux Lookout, and Pickle Lake.
Stay safe and weather-aware, and check back with the NetNewsLedger Weather Desk for the latest updates and flood bulletins across Northwestern Ontario.
