WWCN11 CWTO 130142

YELLOW WATCH - SEVERE THUNDERSTORM

FOR SOUTHERN ONTARIO

UPDATED BY ENVIRONMENT CANADA

AT 9:42 P.M. EDT WEDNESDAY 12 AUGUST 2026.

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YELLOW LEVEL WATCH - SEVERE THUNDERSTORM - FOR:

      BROCKVILLE - LEEDS AND GRENVILLE

      CITY OF OTTAWA

      GATINEAU

      PRESCOTT AND RUSSELL

      CORNWALL - MORRISBURG

      SMITHS FALLS - LANARK - SHARBOT LAKE

      RENFREW - ARNPRIOR - CALABOGIE.



YELLOW LEVEL WATCH - SEVERE THUNDERSTORM - ENDED FOR:

      BARRY'S BAY - KILLALOE

      PETAWAWA - PEMBROKE - COBDEN

      DEEP RIVER - WHITNEY - EASTERN ALGONQUIN PARK.



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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 90 KM/H. 

QUARTER SIZED HAIL. 

HEAVY RAIN. 



WHEN: 

THIS EVENING.



WHEN THUNDER ROARS, GO INDOORS(EXCLAMATION MARK) LIGHTNING KILLS AND 

INJURES CANADIANS EVERY YEAR. SECURE LOOSE OBJECTS. 



HEAVY RAIN CAN CAUSE FLASH FLOODING AND SIGNIFICANT REDUCTIONS TO 

VISIBILITY. 



STRONG WIND GUSTS CAN DAMAGE TREES, BUILDINGS AND OVERTURN VEHICLES. 



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. TO REPORT SEVERE WEATHER IN GATINEAU, SEND AN EMAIL 

TO ONSTORM(AT)EC.GC.CA OR POST REPORTS ON SOCIAL MEDIA USING 

(HASH)QCSTORM. 



FOR MORE INFORMATION: 

HTTPS://WWW.ONTARIO.CA/PAGE/BE-PREPARED-EMERGENCY.



HTTP://WEATHER.GC.CA



END/OSPC