WWCN11 CWTO 200050
YELLOW WATCH - SEVERE THUNDERSTORM
FOR SOUTHERN ONTARIO
UPDATED BY ENVIRONMENT CANADA
AT 8:50 P.M. EDT TUESDAY 19 MAY 2026.
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YELLOW LEVEL WATCH - SEVERE THUNDERSTORM - FOR:
      DUNNVILLE - CALEDONIA - HALDIMAND
      NIAGARA FALLS - WELLAND - SOUTHERN NIAGARA REGION.

YELLOW LEVEL WATCH - SEVERE THUNDERSTORM - ENDED FOR:
      ST. CATHARINES - GRIMSBY - NORTHERN NIAGARA 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 AND 
LARGE HAIL.

WHAT: 
WINDS GUSTING 90 KM/H. 
HAIL UP TO QUARTER SIZED. 

WHEN: 
THIS EVENING. 

ADDITIONAL INFORMATION: 
DAMAGING WIND GUSTS WILL BE THE MAIN THREAT WITH THESE STORMS.

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. HEAVY RAIN CAN CAUSE FLASH FLOODING AND SIGNIFICANT 
REDUCTIONS TO VISIBILITY. 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