Must see: How and why Toronto got so swamped, so fast
Wednesday, August 8, 2018, 3:15 PM - Downtown Toronto was in the wrong place at the wrong time Tuesday night, as a slow-moving area of tropical moisture-fueled rain showers absolutely drenched the city. Radar estimates indicate that some spots received more than 100 mm in less than 3 hours, causing extensive flooding over parts of the downtown core. Didn't see any rain last night? You're not alone -- the heaviest rain was concentrated over a very small area, and that made the difference between seeing more than 70 mm of rain, or 2, over a distance that's probably shorter than your morning commute.
We take a look at some of the amazing images from the event, as well as the cause, below.
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- Radar indicates heaviest rainfall amounts were locally greater than 120 mm
- Heaviest rain fell from North York, near the 400/401 interchange, then south across Downtown Toronto to Toronto Island
- Heavy rain was very localized; Pearson recorded only 6 mm, Buttonville only 2.4 mm
WATCH BELOW: RADAR IMAGES SHOW THE SLOW-MOVING CLUSTER OF STORMS DRENCHING THE CITY
Storms developed around 7:30 pm Tuesday evening, when a lingering afternoon lake breeze off of Lake Ontario butted up against a gradually southward-moving boundary from the northeast, which was likely the lake breeze generated by Georgian Bay. This created a local boundary with enhanced lift right along the 401 corridor north of the city, which in turn teamed up with significant tropical moisture in the atmosphere to unleash a deluge that drifted very slowly south as the storm motion overcame the dying lake breeze -- right over the downtown core.
The result was widespread flash flooding, as rain quickly overwhelmed drainage systems and flooded underpasses, roads, and, in some cases, buildings. Toronto Police services responded to numerous rescue calls through the night, including one case of two men being trapped in a rapidly-filling elevator.
Another round of rain moving in from the south delayed the drainage of standing waters in some places Wednesday morning. Toronto traffic cameras still showed water covering some roads by the start of morning rush hour. Fortunately the heaviest of this latest batch of rain moved over the Niagara Peninsula, rather than over the city itself. Isolated showers and thunderstorms are again possible across the region Wednesday afternoon.
Below are some of the remarkable images and videos that emerged from Tuesday night's flash flooding event.