I had the opportunity to see the storm which struck Edmonton on that afternoon in July 11. These times are as I remember them - I had never seen a thunderstorm develop so FAST. It was truly a WILD one at that, too.
1:45 pm - I noticed that the clouds over my condo were unusually black and I knew something just wasn't right with the weather. So I went out outside with an umbrella and binoculars and walked out to the river valley, where I can get a great view to the south and west.
2:00 pm - I only saw what looked like a mass of ordinary showers, although the clouds were still quite dark directly overhead. But by 2:45 pm, that mass of showers had become a full-fledged thunderstorm with thunder and a few CGs. Scud clouds were moving at a rate I had never seen in years. Quite a bit were also being pulled into the main base at incredible speeds as well. It was already starting to rain, but not very heavily yet.
3:00 pm - I saw what I thought for a second was a wall cloud, but was a rapidly expanding gust front. The colors were awesome - the gust front had an orangey tint to it, while the main rain/hail core was already taking on an evil greenish tinge. The storm kept right on expanding over the south side of Edmonton, as I continued to watch the whole thing. Lightning was already becoming more frequent, accompanied often by loud thunder. The rain was still falling on and off as I watched the clouds. At one point, I saw distinct rotation among the scud clouds right at the base, but there was no mesocyclone nor true wall cloud apparent. To the southeast, I saw what looked like a fat inflow band and a vaulted ceiling. The inflow was sucking in clouds at an incredible speed, too. I could not tell if there was a meso or a wall cloud to the east, because the view was mostly blocked by highrises.
3:30 pm - the rain began to get much heavier, and the clouds to the west were now truly black. I had to get home, and luckily the hail got started after I got home. It just poured and poured and hail kept coming down for almost an hour. In downtown Edmonton, where I was, the hail never got any larger than just under dime-sized, but it did pile up a bit on my balcony. However, hail up to the size of golf balls - and according to some eyewitnesses, even baseball-sized hail were reported in the south side.
I decided to go south of the river to the University of Alberta area shortly after the storm had passed. I noticed drifts of hail up to 2 feet! They looked just like snowdrifts. Quite a few trees lost some leaves, but weren't completely stripped, though. Mammatus clouds were quite extensive as the storm moved away.
West Edmonton Mall got flooded and the entire mall had to be evacuated quickly, as holes were created in the rooof, causing water to come rushing in like waterfalls. Roadways and underpasses were so flooded that vehicles became instant submarines. It is estimated that up to 4"-5" of rain fell in some places, I think - an incredible amount.
I had checked the doppler radar online, but the storm which hit Edmonton was difficult for me to tell if it really was a supercell or not, because neither the shape nor hook was readily apparent. (A few days before, I did actually see a distinct supercell radar signature just west of Edson, about 200 km, or 124 miles west of Edmonton) I couldn't see any overshooting cap on satellite photos, either. But the storm was not an isolated one, as it was in a multi-cell cluster of thunderstorms. Funnels were sighted in that storm. And a couple of tornadoes were sighted, as I heard on the news. Although I did see rotation, I saw no funnels myself.