Jul.19, 2007 - severe thunderstorm warning, shelf cloud

[DarkSky]

WWCN11 CWTO 192012
SEVERE WEATHER BULLETIN
ISSUED BY ENVIRONMENT CANADA
AT 4:12 PM EDT THURSDAY 19 JULY 2007.
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WATCHES/WARNINGS IN EFFECT FOR SOUTHERN ONTARIO...
SEVERE THUNDERSTORM WARNING FOR:
=NEW= NIAGARA FALLS - WELLAND - SOUTHERN NIAGARA REGION
=NEW= ST. CATHARINES - GRIMSBY - NORTHERN NIAGARA REGION
WINDSOR - LEAMINGTON - ESSEX COUNTY.
AT 3:50 EDT THE RADAR IS INDICATING THAT SEVERE THUNDERSTORMS
MOVING SOUTHEAST AT 80 KM/H FROM MICHIGAN ARE EXPECTED TO
ARRIVE SOUTH OF WINDSOR AROUND 4:20 P.M. ALSO SEVERE
THUNDERSTORMS HAVE FORMED NEAR WELLAND AND ARE MOVING SOUTHEAST
AT 50 KM/H.

Shelf cloud passing over (St. Catharines) :

[DarkSky]

The above pictures are showing the bottom red area of this line on the radar: