712  
WWCN11 CWTO 122321  
YELLOW WATCH - SEVERE THUNDERSTORM  
FOR SOUTHERN ONTARIO  
UPDATED BY ENVIRONMENT CANADA  
AT 7:21 P.M. EDT WEDNESDAY 12 AUGUST 2026.  
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YELLOW LEVEL WATCH - SEVERE THUNDERSTORM - FOR:  
CITY OF TORONTO  
BURLINGTON - OAKVILLE  
HALTON HILLS - MILTON  
MISSISSAUGA - BRAMPTON  
VAUGHAN - RICHMOND HILL - MARKHAM  
PICKERING - OSHAWA - SOUTHERN DURHAM REGION.  
 
YELLOW LEVEL WATCH - SEVERE THUNDERSTORM - ENDED FOR:  
CALEDON  
NEWMARKET - GEORGINA - NORTHERN YORK REGION  
UXBRIDGE - BEAVERTON - NORTHERN DURHAM REGION.  
 
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IMPACT LEVEL: MODERATE  
FORECAST CONFIDENCE: HIGH  
 
==DISCUSSION==  
 
CONDITIONS ARE FAVOURABLE FOR THE DEVELOPMENT OF SEVERE  
THUNDERSTORMS THAT MAY BE CAPABLE OF PRODUCING STRONG WIND GUSTS,  
LARGE HAIL AND HEAVY RAIN.  
 
WHAT:  
WIND GUSTS NEAR 100 KM/H.  
TOONIE SIZED HAIL.  
HEAVY RAIN IN EXCESS OF 60 MM.  
 
WHEN:  
CONTINUING INTO THIS EVENING.  
 
ADDITIONAL INFORMATION:  
THE HIGHEST RAINFALL AMOUNTS ARE EXPECTED FOR AREAS THAT RECEIVE  
MULTIPLE THUNDERSTORMS.  
 
LOCAL UTILITY OUTAGES ARE POSSIBLE. FAST-MOVING AND RAPIDLY RISING  
WATER CAN SWEEP VEHICLES AWAY AND DAMAGE INFRASTRUCTURE. WHEN  
THUNDER ROARS, GO INDOORS(EXCLAMATION MARK) LIGHTNING KILLS AND  
INJURES CANADIANS EVERY YEAR. SECURE LOOSE OBJECTS.  
 
SEVERE THUNDERSTORM WATCHES ARE ISSUED WHEN CONDITIONS ARE  
FAVOURABLE FOR THE DEVELOPMENT OF THUNDERSTORMS CAPABLE OF PRODUCING  
DAMAGING HAIL, WIND OR RAIN.  
 
EMERGENCY MANAGEMENT ONTARIO RECOMMENDS THAT YOU TAKE COVER  
IMMEDIATELY IF THREATENING WEATHER APPROACHES.  
 
PLEASE CONTINUE TO MONITOR ALERTS AND FORECASTS ISSUED BY  
ENVIRONMENT CANADA.  
 
TO REPORT SEVERE WEATHER IN ONTARIO, SEND AN EMAIL TO  
ONSTORM(AT)EC.GC.CA OR POST REPORTS ON SOCIAL MEDIA USING  
(HASH)ONSTORM.  
 
FOR MORE INFORMATION:  
HTTPS://WWW.ONTARIO.CA/PAGE/BE-PREPARED-EMERGENCY.  
 
HTTP://WEATHER.GC.CA  
 
END/OSPC  
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