THUNDERSTORM: Montréal Island area
yellow watch – severe thunderstorm – in effect
Issued: 10:28 AM EDT, Tuesday, July 21, 2026
Expires: 2:00 AM EDT, Wednesday, July 22, 2026
Urgency: Expected
Severity: Moderate
Impact Level: Moderate
Forecast Confidence: High
Conditions are favourable for the development of severe thunderstorms capable of producing strong wind gusts and heavy rain this afternoon and this evening.
Severe thunderstorms may produce tornadoes.
Nautical activities may be hazardous due to sudden, severe wind gusts over bodies of water.
Damage to roofs, fences, branches or soft shelters is possible.
Heavy rain can cause flash flooding and significant reductions to visibility.
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to QCstorm@ec.gc.ca or post reports on X using #QCStorm.
When thunder roars, go indoors! Lightning kills and injures Canadians every year.
SQUALL: Montréal to Trois-Rivières
squall watch in effect
Issued: 10:03 AM EDT, Tuesday, July 21, 2026
Expires: 10:02 PM EDT, Tuesday, July 21, 2026
Urgency: Expected
Severity: Severe
Today, between 3 pm and 8 pm, conditions will be favourable for the development of squalls accompanied by gusts of up to 85 km/h and frequent lightning.
Please continue to monitor alerts and forecasts issued by Environment Canada. For more information monitor Canadian Coast Guard radio or Weatheradio stations.
Vessels without lightning protection should make their way to shore immediately. Mariners are advised to prepare for potential squalls. Vulnerable vessels are most at risk and should seek safe harbour if underway. Consider delaying or postponing travel in areas under the Squall Watch.
SQUALL: Richelieu River and Northern Lake Champlain
squall watch in effect
Issued: 10:03 AM EDT, Tuesday, July 21, 2026
Expires: 10:02 PM EDT, Tuesday, July 21, 2026
Urgency: Expected
Severity: Severe
Today, between 3 pm and 8 pm, conditions will be favourable for the development of squalls accompanied by gusts of up to 85 km/h and frequent lightning.
Please continue to monitor alerts and forecasts issued by Environment Canada. For more information monitor Canadian Coast Guard radio or Weatheradio stations.
Vessels without lightning protection should make their way to shore immediately. Mariners are advised to prepare for potential squalls. Vulnerable vessels are most at risk and should seek safe harbour if underway. Consider delaying or postponing travel in areas under the Squall Watch.
