Heavy rain warnings blanket parts of Northwestern Ontario

THUNDER BAY · Environment Canada has issued rainfall warnings for parts of Northwestern Ontario, forecasting up to 50 millimetres of additional rain Wednesday in areas from Armstrong through Greenstone to Nipigon. The warnings cover the Nipigon area and the Geraldton-Longlac-Caramat forecast area used for Greenstone. The federal weather agency says multi-day rainfall totals could reach near 80 millimetres, with even higher amounts possible. A special weather statement is also in effect for Armstrong, forecasting 30 to 50 millimetres of rain from Wednesday into Thursday.

"Water may pool on roads and washouts are possible near rivers, creeks and culverts," the statement for Armstrong said. The main travel concerns across the warned regions include fog, ponding water on roadways, and north wind gusts reaching 40 to 60 kilometres per hour. The heavy rain is expected before colder air moves in, bringing a rain-snow mix to areas east of Lake Nipigon later in the week. In the Greenstone area, represented by the Geraldton-Longlac-Caramat forecast, temperatures will stay near 8 degrees Celsius Wednesday with 30 to 40 millimetres of heavy rain expected. Another 10 to 20 millimetres is forecast overnight, with a low of 1 degree. Nipigon will stay near 10 degrees with similar rainfall amounts, and north winds are expected to increase to 40 km/h with gusts to 60 overnight as the temperature falls to 2 degrees.

Conditions are forecast to improve in western parts of the region. Kenora has a 40 per cent chance of morning drizzle or showers before afternoon breaks, with a high of 9 degrees. Red Lake will reach 8 degrees and clear in the afternoon. Both areas, along with Dryden and Sioux Lookout, have a 30 per cent chance of overnight flurries, with lows near 0 degrees and north gusts of 40 to 50 km/h. Fort Frances will stay near 9 degrees as rain ends in the afternoon. Environment Canada advises residents in the warning areas to use a waterproof shell and waterproof footwear. Drivers are urged to keep a dry insulating layer in their vehicle and to avoid water-covered roads. The agency notes that one millimetre of rain equals one litre of water spread over one square metre, meaning a 50 millimetre rainfall places 50 litres of water on every square metre of level ground before runoff or absorption.

Colder air arrives Thursday, changing rain to a mix of rain and snow in eastern districts. Armstrong will have a 60 per cent chance of rain and a high near 2 degrees before plunging to a low of -9 degrees overnight. Greenstone will get periods of rain or snow, reaching 2 degrees before falling to -5 degrees. Nipigon keeps a 60 per cent chance of rain near 4 degrees, followed by a 40 per cent chance of flurries or rain showers and a low near -6 degrees. Add gloves and a warm mid-layer Thursday as wet surfaces may turn icy after dark. Friday is forecast to be sunny across the region. Highs will be about 6 degrees in Kenora, Red Lake, Dryden and Ignace, 5 degrees in Fort Frances and Sioux Lookout, 4 degrees in Armstrong and Nipigon, and 3 degrees in Greenstone. Clear Friday-night lows will range from about 1 degree in the western districts to -5 or -6 degrees around Greenstone and Armstrong.

With files from NetNewsLedger