WWCN11 CWTO 181237

YELLOW WATCH - SEVERE THUNDERSTORM

FOR SOUTHERN ONTARIO

ISSUED BY ENVIRONMENT CANADA

AT 8:37 A.M. EDT SATURDAY 18 JULY 2026.

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YELLOW LEVEL WATCH - SEVERE THUNDERSTORM - FOR:

=NEW= HURON - PERTH

=NEW= WATERLOO - WELLINGTON

=NEW= ORANGEVILLE - GRAND VALLEY - SOUTHERN DUFFERIN COUNTY

=NEW= SHELBURNE - MANSFIELD - NORTHERN DUFFERIN COUNTY

=NEW= SAUGEEN SHORES - KINCARDINE - SOUTHERN BRUCE COUNTY

=NEW= HANOVER - DUNDALK - SOUTHERN GREY COUNTY.



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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 UP TO 100 KM/H. 

QUARTER SIZED HAIL. 

RAINFALL AMOUNTS 25 TO 50 MM. 



WHEN: 

BEGINNING THIS MORNING INTO THIS AFTERNOON. 



ADDITIONAL COMMENTS: 

A COLD FRONT OVER MICHIGAN IS EXPECTED TO BRING A LINE OF 

THUNDERSTORMS AS IT MOVES SOUTHEAST OVER THE AREA TODAY.



DRIVING CONDITIONS MAY BE DIFFICULT. LOCAL UTILITY OUTAGES ARE 

POSSIBLE. DAMAGE TO ROOFS, FENCES, BRANCHES OR SOFT SHELTERS IS 

POSSIBLE. 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 X USING (HASH)ONSTORM. 



FOR MORE INFORMATION: 

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



HTTP://WEATHER.GC.CA



END/OSPC