WUCN11 CWTO 050006

YELLOW WARNING - SEVERE THUNDERSTORM

FOR SOUTHERN ONTARIO

ISSUED BY ENVIRONMENT CANADA

AT 8:06 P.M. EDT MONDAY 4 MAY 2026.

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YELLOW LEVEL WARNING - SEVERE THUNDERSTORM - FOR:

=NEW= SARNIA - PETROLIA - WESTERN LAMBTON COUNTY.



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IMPACT LEVEL: MODERATE

FORECAST CONFIDENCE: HIGH



==DISCUSSION==



UPDATED OR ENDED BY 9:29 P.M. EDT.



AT 8:05 P.M. EDT, ENVIRONMENT CANADA METEOROLOGISTS ARE TRACKING A 

SEVERE THUNDERSTORM CAPABLE OF PRODUCING VERY STRONG WIND GUSTS, UP 

TO NICKEL SIZE HAIL AND HEAVY RAIN.



A SEVERE THUNDERSTORM WAS LOCATED 20 KILOMETRES NORTH OF TECUMSEH, 

MOVING NORTHEAST AT 75 KM/H. 



HAZARDS: 

- UP TO 90 KM/H WIND GUSTS. 

- UP TO QUARTER SIZE HAIL. 

- HEAVY RAINFALL. 



LOCATIONS IMPACTED INCLUDE: 

PETROLIA, WALLACEBURG, OIL SPRINGS, WALPOLE ISLAND, PORT LAMBTON, 

SOMBRA, BECHER, WILKESPORT, DRESDEN, BRIGDEN, BENTPATH, OIL CITY, 

FLORENCE.



LOCAL UTILITY OUTAGES ARE LIKELY. DAMAGE TO ROOFS, FENCES, SOFT 

SHELTERS OR TREES IS LIKELY. LARGE HAIL MAY CAUSE SIGNIFICANT DAMAGE 

AND INJURY. TAKE IMMEDIATE COVER IF A THUNDERSTORM APPROACHES. IF 

OUTSIDE, PROTECT YOURSELF FROM FLYING DEBRIS AND HAIL. SEVERE 

THUNDERSTORM WARNINGS ARE ISSUED WHEN IMMINENT OR OCCURRING 

THUNDERSTORMS ARE EXPECTED TO PRODUCE 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