Background:

The night before was a very long one. I felt that the 4th was going to be a very interesting day and thus, wanted to make sure I had done my analysis of the models. This took me a lot longer than I thought and finally got to bed around 3 am figuring there was a chance of tornadoes in Ontario.

The chase would depend on the timing of the cold front. As with many cold fronts situated in the Lake Superior region, they tend to slow down crossing the Great Lakes and I was hoping this would happen. All the models indicated that there was sufficient shear and veering with height in the atmosphere to cause any storms that form to rotate but there was weak surface winds and this concerned me. I decided that it was a chase day and went to bed.

I woke up around 10 am and looked at my lightning detection system and noticed that I was getting strikes in the western sections of Southern Ontario. Radar confirmed that storms had fired in the Sarnia and Hanover area and were tracking east. I decided to take a stab at chasing them as I felt they would become severe even this early in the morning.

Chase #1:

I decided to intercept the northern storms in Elmira and time it perfectly. I caught the first storm and noticed that it was beginning to right turn and show signs of rotation in it. A severe thunderstorm warning came out about 11 am and a quick call to EC told me that rotation had been detected. I informed them that it was there but having trouble becoming surfaced based. Needless to say, I chased this storm into Guelph as it intensified.

I stayed north of Guelph to keep on good road networks and swung around after the core hit. The roads were covered in hail with the largest I found was 3.75 cm (1.5 inches). I reported this to EC around 12 pm and watched the second storm plow into the region. As the flow was linear, the storms were training over the same place and some evidence of flood became apparent. The second storm seemed a lot more intense than the first with tons of CG lightning hitting all around me.

Wall Cloud with Funnel Trying to Form

I changed position and within 5 mins noticed this nice wall cloud forming and condensing near the ground. I was about to call it in as the rotation was picking up but some cold outflow winds from the third cell hit it (could feel it rush by me) and the wall cloud with the possible funnel dissipated. Another cell hit after this one but it was weaker than the other 2 and I decided to head home and begin analysis for the afternoon storms. The show had just begun. What I liked was that the storms showed evidence of rotation this early in the morning. On the way home I talked with Ron G about this and he said that he had just gotten up and was starting the CanWarn net early. He had been up most of the night analyzing things as well and figure the afternoon show was going to be very interesting.

Chase #2:

After the nice morning excitement, I headed home and started to do some analysis on the possible afternoon storms. I was a little concerned that the morning's convection would stabilize the area around Guelph and cause me to chase further north or west. After running a few more models and hand plotting surface observations, I got on the phone to Des Cairns. He was in Hanover watching some cumulus starting to build. I decided that I would target Arthur and change locations as new data came in. About half way there I gave a call to Ron Gravelle and he told me that I should wait there but not go further north than that.

Just north of Arthur, some beautiful cumulus clouds started to build and I watched them but they did not have any indications of sustaining the storm. Well this was great. I was deciding heading further to the Southwest when the first warnings started coming in from the Sarnia area around 3 pm. This made my mind up and I headed towards Stratford. About half way there, tornado warnings started being issued for areas south of Sarnia and east of Barrie. Great. Storms firing up to my north and south but nothing firing up in my target zone (which was in between the 2). However the Sarnia storm was very mature and producing some gorgeous mammatus features that stretched for almost 100 kms. A simply perfect sight.

New!
 

As I came into Stratford, I noticed a nice vaulted updraft to my northwest and this would track over London. A quick phone call to Ron, told me it was there but not indicating rotation yet but asked if I would head back to spot in the Kitchener area as he felt things would get interesting in the next hour and that my forecast was getting better.

I headed south to Woodstock and then took off on the 401 back to Kitchener. About 40 kms from KW, I could see the towers rising into the mammatus field from the Sarnia storm but there was evidence of rotation. As I approached Aye, Ontario I called Ron and he told me that the cell of KW was weakening but the cell to the west of it was really cranking up. I got confused and said I think I am in that cell now and "Oh, it is really starting to get organized, I need to get off this highway."

I got off at the Ayr exit (#268) and headed south on Reidsville Road to Alps Rod and headed west. About 1/2 kms down the road I pulled over and watched as a wall cloud started to form.

A quick call to Ron about it and that I was on it and there was rotation becoming evident. Told him I would call him back.

As I filmed it, it started to wrap rain and hail around me. I was starting to lose visibility. A chaser nightmare. I turned around and headed back east to Reidville road and swung south again. As there was a ton of trees, I lost the wall cloud but was watching at every point so that I did not overrun it. I came down a hill to a train track when there to my southwest was a developing tornado. I had the film running but at the exact time, the train lights started to flash and I got across and set up to film the multiple vortex tornado (2 tornadoes rotating within a larger circulation). The stills below show a point after the 2 vortexs combined into a single tornado circulation.

I got out to take a still shot and phone Ron to report it and the train just started to pass and the engineer and conductor looked at me and then I pointed at the tornado and they looked in amazement before they started to slow the train down. There was no danger for them but it was good to see they took it seriously.

The 2 tornadoes merged into one and within a minute they had dissipated. I got closer to the wall cloud thinking it may regenerate and got a little too close by the next shot. the funnel is still over my head but the rotation is really strong. In fact, it looks like another funnel tried to form in the top right of this shot about half way.

I got lost in the road network from this point on as the trees really cause some dangerous problems as you could not see much. I decided to call the chase off for my safety.

I headed home and made a bunch of phone calls to other chasers and came into Guelph when I noticed another cell forming. This cell had some nice definition forming but I was very tired. I made a quick phone call to Mark Robinson and he said he was near the area and decided to chase it. I wish I did as I formed a tornado northwest of Campbellville and did some damage to some barns.

All in all, a very good chase day. Most of the tornadoes occurred in rural areas and did little damage. Going to be nice to add this one to my chase highlights film. Special thanks to Ron Gravelle, Des Cairns, Jack Kertzie and Mark Robinson for nowcasting and spotter obs from the field.

New Data: I went back the next day to do some damage assessment. It took over 2 hours to find any evidence of a touchdown but after talking with some people, I found that the tornado just missed a subdivision and hit open field. The picture below shows how the grass was sand blasted (turned yellow) and all the loose vegetation stripped from the area.

Additional Reports:

WOCN10 CWTO 050203
GENERAL WEATHER STATEMENT
ISSUED BY ENVIRONMENT CANADA. REGIONAL CENTRE TORONTO ONTARIO.
10.03 PM EDT WEDNESDAY 4 JULY 2001.

THE FOLLOWING IS A SUMMARY OF THE SEVERE WEATHER OUTBREAK ACROSS
SOUTHERN ONTARIO ON WEDNESDAY JULY 4.

SARNIA..(9 AM)....................MARBLE-SIZED HAIL
WEST TORONTO..(NEAR MIDDAY).......POSSIBLE TORNADO IN MISSISSAUGA
TORONTO ISLAND (EARLY AFTERNOON)..HOVERCRAFT REPORTED FUNNEL CLOUD
TORONTO CITY CENTRE AIRPORT..(1.20 PM)... 89 KM/H WIND GUSTS
TORONTO CITY CENTRE AIRPORT..(TO 2 PM)... 31 MM RAIN IN 1.5 HOURS
ELMIRA (11.15 AM).................GOLF BALL-SIZED HAIL
ACTON..(11.40 AM).................GOLF BALL-SIZED HAIL
CAMBRIDGE..(LATE MORNING).........GOLF BALL-SIZED HAIL
GUELPH..(NEAR NOON)...............1.5 INCH HAIL WITH 6 INCH
HAIL DRIFTS ALONG ROADS..AND LOCAL FLOODING
FERGUS..(EARLY AFTERNOON).........QUARTER SIZED HAIL
ELMIRA..(EARLY AFTERNOON).........FLOODED ROADS
NEAR BANCROFT...(2:30 PM).........2.3 CM HAIL
WEST OF BANCROFT NEAR HIGHLAND GROVE...(2:30 PM)..UNCONFIRMED
TORNADO WITH HYDRO POLES AND TREES DOWN
ARGYLE (2:45PM)...................TORNADO REPORTED
SARNIA (3 PM).....................MARBLE-SIZED HAIL
SARNIA (AFTER 3 PM)...............TREES AND POWER LINES DOWNED
SARNIA AREA (AFTER 3 PM)..........QUARTER-SIZED HAIL
PETROLIA (3:30 PM)................STRONG ROTATION ON DOPPLER RADAR
BUT NO CONFIRMED TORNADO
SOUTH OF LAKE SIMCOE (4 PM).......STRONG ROTATION ON DOPPLER RADAR
WITH LONG-LIVED WALL CLOUDS ASSOCIATED
BARRIE (3:10 PM)..................NICKEL-SIZED HAIL
REGIONAL RD 30 IN PETERBOROUGH AREA..(MID AFTERNOON)..FUNNEL CLOUD
WITH BARN ROOF LIFTED OFF...SILO SHEARED OFF.
SHELBURNE..(4:30 PM)...............MARBLE-SIZED HAIL
REGIONAL RD 30/DURHAM 15 (DURHAM REGION)..(4 PM)..MARBLE-SIZED HAIL
ARTHUR..(5 PM).....................TORNADO SIGHTED
AYR (SOUTH OF CAMBRIDGE)..(5 PM)...TORNADO SIGHTED THEN LIFTED
AND TOUCHED DOWN AGAIN NEAR ST GEORGE WEST OF HAMILTON
CAMPBELLVILLE/MILTON..(7:45 PM)....TORNADO LIFTED PARTIAL ROOF OFF
BARN
...AND DOWNED NUMEROUS TREES WITH DEBRIS TOSSED ABOUT
...REPORTEDLY 100 CARS STOPPED ON HWY 401 NEAR MILTON WATCHING
TORNADO

END/ASHTON

WOCN10 CWTO 060252
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 LOCATION

MISSISSAUGA NEAR NOON NO DAMAGE REPORTS

ARGYLE 2.30 PM F0 DAMAGE - TORNADO SIGHTED

BANCROFT 2.30 PM UNCONFIRMED TORNADO
HYDRO LINES/TREES DOWN

FENELON FALLS 2.45 PM F1 DAMAGE - SILO KNOCKED DOWN

ARTHUR 4.55 PM TORNADO CONFIRMED ON GROUND
BY CANWARN STORM SPOTTER
UNKNOWN DAMAGE

AYR TO ST GEORGE 5.00 PM F0 DAMAGE
-5.30 PM

CAMPBELLVILLE 7.25 PM F0 DAMAGE - VIDEO FOOTAGE
- PART OF ROOF RIPPED OFF
- TREES DOWN

END/KUHN

All Photos and information unless otherwise noted are copyrighted 2001 by Dave Patrick.  Any use other than authorized by me is against the law.  If you wish to contact me regarding use of these photos, please e-mail me. Images unaltered digitally (except where stated)