July 4, 2001 CANWARN A  DAY  TO  REMEMBER by Paul VE3SY

As we are all aware, Wednesday July 4th 2001 will be remembered by area CANWARN spotters and storm chasers as the day of the seven Tornados.

The Waterloo Region CANWARN net was active from shortly after 11:00 am until 8:00PM in the evening and saw a flurry of severe weather related activity as the net went from condition Green, to Yellow to Red as Tornadoes were touching down all around our VE3KSR CANWARN coverage area. 

Ron VA3TVS

A few days after the storm I sat down with our CANWARN coordinator Ron Gravelle VA3TVS and interviewed him on the events leading up to and during the storms path through Southern Ontario.

As well, be sure to read the story filed with us by Storm Chaser Mark Robinson who was able to witness and tape on of the many tornados that touched down during the storm. 

Paul

At noon on Tuesday July 3rd, the Storm Prediction Center in Norman Oklahoma had Southern Ontario under a slight risk of severe weather.  Ron maintained a vigilant watch on this US based site and by late evening both the Norman OK and the Environment Canada web sites were showing risk of severe thunderstorms. Ron then started studying publicly available charted information from the University of Oklahoma, University of Chicago comparing airflow speed and direction at seven different levels in the atmosphere. Based on various wind directions at various heights Ron was able to get a feel for what type of weather may be approaching us here in Southern Ontario. By the wee hours of the morning Ron saw that all of the severe weather parameters were in place and Southern Ontario would be in for a "pretty good show" on Wednesday so Ron hit the sack about 4:30AM.

Rising shortly before 11am Ron scanned the radar images and could see lots of storm scale rotation reaffirming his earlier predictions. The CANWARN pager brought Ron out from behind his computer monitor at 11:05 AM and after a brief phone conversation with the severe weather desk in Toronto Ron brought the Waterloo Regional CANWARN net up in condition green at 11:15. Almost immediately Golf ball size hail was reported by Dave Patrick east of Guelph and CANWARN  spotters reported hail in the Fairview Plaza area of Kitchener and very heavy rain and hail North of Elmira.  Ron immediately took the CANWARN net to condition Yellow.

The Action Begins
About 2:30 PM Marg Verbeek, the Waterloo Region Emergency Planning Coordinator, called Ron for a severe weather forecast.  Ron indicated that she was well aware of the situation but required a detailed storm system analysis in order to alert regional emergency services.

More heavy hail and flooded road reports streamed in from the Fergus and Elmira areas.  Then about 2:45pm a Tornado was reported on the ground near Argyle Ontario followed by another citizens report of a funnel dropping from the sky near Arthur however due to trees there was no confirmation if it reached the ground.

Then multiple reports from spotters in the Ayr area just south of Kitchener started coming in via VE3KSR and by phone from storm chaser Dave Patrick of Fergus who was shooting video of the funnel (see his Weather Network image) which did not reach the ground.  Glenn VE3GCI who lives in Ayr was also watching the tornado and reported his sighting to Ron at CANWARN Net Control and Ron immediately took the net to condition Red. 

Following earlier discussions with Ron as to where a tornado was likely to develop, Dave was in the Ayr area . Ron's forecast was "right on" as Dave was able to confirm multiple vortices in this tornado as he followed it along it's path developing severe thunderstorms as it moved eastward before dissipating around St. George.

At this point the severe weather moved out of our area towards the east and Ron returned the CANWARN net to condition green and started to relax after a very long net operation when reaching for his Sprite the phone rang, it was Mark Robinson, screaming "Tornado on the ground!!" "Tornado on the ground!!".  A very excited Mark (this was his first tornado sighting) grabbed his video camera and capture the funnel on tape. (see video capture from Mark's tape from The Weather Network) Fellow storm chaser Jack Kertzie from Buffalo NY SKYWARN was also in the area and also captured the tornado as it moved along the ground for some 20 minutes before dissipating as it dropped over the Niagara escarpment. (see left image of Jacks video capture) A security guard at Mohawk Raceway at Campbellville also spotted the funnel and trained the remote security camera located high above the racetrack grandstand on the Tornado and was able to capture it on tape as it moved past the facility.

Then it was over…. The skies cleared and Ron finally had a bite to eat and a chance for some rest.

Lessons Learned

1.	Whenever the net is in condition Yellow, no one should report ANYTHING other than the following:
	*	Rising scud into the clouds
	*	Rotating wall clouds
	*	Pea size or larger hail
	*	Very high winds of sufficient strength to damage trees or buildings
		Extremely heavy rain

PLEASE - no reports like "it's raining here", "sky is quite black here" , "it's windy here" should be reported during condition Yellow or Red.

2. A second person is definitely needed at Net Control to handle the radio traffic while the net is in condition Yellow or Red.

Thank You
Ron would like to personally thank the following spotters who assisted during the July 4th CANWARN net.

Storm Log from Environment Canada
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.

•  9:00 am Sarnia.. Marble-sized hail

• 11.15 am Elmira ..... Golf ball-sized hail

• 11:40 am Acton.....golf ball-sized hail

• Cambridge ..(late morning).........golf ball-sized hail

• 12:00 pm Guelph....1.5 inch hail with 6 inch hail drifts along roads and local flooding

• 12:00 pm West Toronto.. Possible tornado in Mississauga

• Fergus ..(early afternoon).........quarter sized hail

• Elmira ..(early afternoon).........flooded roads

• 1:20pm Toronto island .. Hovercraft reported funnel cloud Toronto city centre airport..(1.20 pm)... 89 km/h wind gusts

• 2:00 pm Toronto city centre airport.. 31 mm rain in 1.5 hours

• 2:30pm near Bancroft...2.3 cm hail west of Bancroft near Highland Grove.. unconfirmed tornado with hydro poles and trees down

• 2:45pm Argyle ...Tornado reported

• Regional rd 30 in Peterborough area.. (mid afternoon).. funnel cloud with barn roof lifted off...silo sheared off.

• 3:00 Sarnia ....marble-sized hail

• 3:10pm Sarnia ..trees and power lines downed quarter- sized hail

• 3:10 Barrie ....nickel-sized hail

• 3:30pm Petrolia ...strong rotation on Doppler radar but no confirmed tornado

• 4:00pm south of Lake Simcoe ...strong rotation on doppler radar with long-lived wall clouds associated

• 4:30pm Shelburne.....marble-sized hail

• 5:00pm Arthur.....tornado sighted

• 5:00pm Ayr (south of Cambridge) .. tornado sighted then lifted and touched down again near St. George west of Hamilton

• 7:45 Campbellville/Milton....tornado spotted lifted partial roof off barn and downed numerous trees with debris tossed about reportedly 100 cars stopped on hwy 401 near Milton watching tornado

Video captures courtesy of the Weather Network

Storm Related Links

• Storm Chaser Mark Robinson "In His Own Words"

• Dave Patrick's Ontario Weather web site

• Storm Chaser Marc Nagey's Web site