JULY 4TH - SOUTHERN ONTARIO TORNADO 'OUTBREAK'

Busy day for active weather - hot humid instability, combined with the jet stream being directly overhead and a strong cold front sweeping across from the east caused at least 4 confirmed tornadoes, as well as a few more that are unconfirmed.  Radar summary showing echo tops shows the size of these storms along the front and radar loop showing their direction.  Good jobs by Environment Canada and The Weather Network staying on top of things all day.
Thanks to Des Cairns for this radial velocity image showing localized rotation in one of the cells.

Photos in Campbellville, ON,  courtesy of Jack Kertzie
Click thumbnails for full-size images:

Newpaper interview with chaser Mark Robinson (Toronto SUN)
Click image below for full-size article:

Below are some vidcaps from The Weather Network,
 and TV news stations CityTV, CFTO-TV, GlobalTV, and CHCH-TV:
(If anybody knows who shot the amateur video in the caps below please tell me so I can give due credit)
Ayr, Ont tornado (below) captured by Mark Robinson.


TORNADO WARNING

ISSUED BY ENVIRONMENT CANADA. REGIONAL CENTRE TORONTO ONTARIO.
5.21 PM EDT WEDNESDAY 4 JULY 2001.
SEVERE THUNDERSTORM WARNING UPGRADED TO TORNADO WARNING FOR..
WELLINGTON COUNTY.
A STORM SPOTTER HAS SIGHTED A TORNADO NEAR ARTHUR AT 5 PM.  MOTION IS TO THE EAST AT ABOUT 60 KM/H. IT IS EXPECTED TO AFFECT
BELLWOOD AREA AND ERIN BY 6:15 PM.  THIS WARNING IS IN EFFECT UNTIL 7.00 PM.
END/1/AGA
TORNADO WARNING
ISSUED BY ENVIRONMENT CANADA. REGIONAL CENTRE TORONTO ONTARIO.
5.34 PM EDT WEDNESDAY 4 JULY 2001.
SEVERE THUNDERSTORM WARNING UPGRADED TO TORNADO WARNING FOR..
HAMILTON
BRANT COUNTY.
TORNADO WARNING ISSUED FOR..
EASTERN HALDIMAND AND NORFOLK COUNTIES
REGIONAL MUNICIPALITY OF NIAGARA.
A STORM SPOTTER HAS SIGHTED A TORNADO NEAR ST GEORGE AT 5:20 PM. MOTION IS TO THE EAST AT ABOUT 60 KM/H. THE STORM IS EXPECTED
TO BE IN THE HAMILTON AREA BY 6 PM. IT MAY ALSO GRAZE EASTERN HALDIMAND-NORFOLK AND NIAGARA COUNTIES AS WELL.  THIS WARNING IS IN EFFECT UNTIL 7.30 PM.

TORNADO WARNING

ISSUED BY ENVIRONMENT CANADA. REGIONAL CENTRE TORONTO ONTARIO.
7.43 PM EDT WEDNESDAY 4 JULY 2001.
SEVERE THUNDERSTORM WARNING UPGRADED TO TORNADO WARNING FOR..
REGIONAL MUNICIPALITY OF HALTON
SOUTHERN REGIONAL MUNICIPALITY OF PEEL.
STORM SPOTTERS HAVE SIGHTED ONE POSSIBLY TWO TORNADOES TOUCHING DOWN IN THE BURLINGTON TO MILTON AREA. ONE IS REPORTED TO BE
A SIZABLE TORNADO. MOTION IS SOUTHEAST AROUND 30 KM/H. TAKE SHELTER IMMEDIATELY.
UPDATED EXPERIMENTAL ELBOW QPF DISCUSSION.
ISSUED AT 6.10 PM EDT WEDNESDAY 4 JULY, 2001.
 
SIGNIFICANT TORNADO/SEVERE WEATHER OUTBREAK CURRENTLY ONGOING IN SOUTHERN ONTARIO. SEVERAL UNCONFIRMED AND A FEW CONFIRMED TORNADO REPORTS FROM CANWARN SPOTTERS. MOST OF THE SUPERCELLS HAD DEVELOPED ALONG THE SOUTHWESTERN ENDS OF LINES OF CONVECTION FOCUSSED BY LAKE-BREEZE BOUNDARIES.  AT 21Z...THE COLD FRONT WAS LOCATED FROM NORTH BAY TO SAGINAW BAY TO EXTREME SOUTHERN LAKE MICHIGAN, AND A PRE-FRONTAL PRESSURE TROUGH WAS LOCATED FROM SOUTH OF LAKE SIMCOE TO SOUTH OF ST. THOMAS. SURFACE BASED CAPE AROUND 2500 J/KG AND STORM RELATIVE HELICITY NEAR 200 METRES SQUARED PER SECOND SQUARED
ASSOCIATED WITH THE PRE-FRONTAL TROUGH WILL BE THE FOCUS FOR CONTINUED SUPERCELLS AND POSSIBLE TORNADIC STORMS FOR THE NEXT ONE TO TWO HOURS UNTIL IT MOVES SOUTHEASTWARD OUT OF THE REGION.
END/BRIAN MURPHY
GENERAL WEATHER STATEMENT
ISSUED BY ENVIRONMENT CANADA. REGIONAL CENTRE TORONTO ONTARIO.
10.52 PM EDT THURSDAY 5 JULY 2001.
...SOUTHERN ONTARIO TORNADO SUMMARY FROM THE 4TH OF JULY...
 FOLLOWING IS A SUMMARY OF THE LOCATION OF TORNADOES AND DAMAGE FROM SEVERE THUNDERSTORMS PRODUCED BY TWO COLD FRONTS THAT SWEPT ACROSS SOUTHERN ONTARIO ON THE 4TH OF JULY.

TORNADO LOCATION TIME DESCRIPTION
MISSISSAUGA Noon No damage reports
ARGYLE 2.30pm F0 DAMAGE - TORNADO SIGHTED
BANCROFT 2.30pm UNCONFIRMTED TORNADO, HYRO LINES/TREES DOWN
FENELON FALLS 2.45pm F1 DAMAGE - SILO KNOCKED DOWN
ARTHUR 4.55pm TORNADO CONFIRMED ON GROUND BY CANWARN STORM
SPOTTER, UNKNOWN DAMAGE
AYR -> ST. GEORGE 5.00pm F0 DAMAGE
CAMPBELLVILLE 7.25pm F0 DAMAGE - VIDEO FOOTAGE, PART OF ROOF TORN OFF, TREES DOWN

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