Southwestern Ontario and Niagara got just pasted yesterday and the day before. A steady stream of large and small cells out of Michigan, Illinois and Indiana out of that cold front. Eastern Ontario missed the brunt of it. EWR sent out at least dozen alerts.

Some radar scans below of Apr 6th and 7th – this sort of stuiff went on for nearly a full 36 hour period. As much as 65-80mm of rain got dumped in the triangle between London, Sarnia and Chatham.

On Tues, after a night of small, but fairly intense popup cells over the north shore of lake Erie, this MCS grew up on the lee shore of Lake Michigan and emigrated to Canada about 12:45 Tues afternoon. crossing the Wallaceburg area about 1 pm. The southermost cell flirted with being a full grown supercell all the way across its trip. Although it tripped off ETVS and TVS signatures, I don’t know if anything came to ground. Most of the signatures were elevated. Grand Rapids never issued tornado warniings for it, but
Indianapolis did.

Composite reflectivity scan

On Wednesday, Welland got pounded with this cell at about 1:42pm:

The base velocity profile for this storm (at 1:47pm) looked like this:

In 3-D, cell looked like this from the east (ie from Buffalo) ( looking at the 45-55dBZ return profile). The inflow jet stands out…

And the same view with all echo return layers, transparent, (the purple hail core is embedded and doesn’t show through the denser rain wrap) the weak echo region of the main updraft shows just above the inflow jet:

All returns, transparent, viewed from the south (out over Lake Erie). The strong upper winds are clear and evidence of how fast-moving these storms were. I was surprised at how skinny this was! It was dropping rain at the rate of 10-15 mm/hr around this time:

another view:

And finally, 10 minutes later, it appears to stretch out even more. The clipping of the radar at KBUF is evident in the flattopping. I’m not sure, since the cell is very close to the radar site, how much of the slope is an anomaly of the rotational scan time and how much is actual wind profile: