Rapidly deepening low pressure system dragging mild Gulf of Mexico air over parts of southern Ontario. At midnight, London is 11C and Sarnia is 14C, thankfully melting accreted ice on trees, etc. Will be a much different story tomorrow with near-blizzard conditions. #ONstorm

Thunder reported with this compact storm moving into southwestern Ontario. Just one more weather type affecting the province right now. Northbound Hwy 400 north of Toronto currently closed due to multiple collisions with icy roads. #ONstorm

Sudden snow squall coming through the #LdnOnt area. Lots of blowing snow, and greatly reduced visibility. Take care out there! #ONstorm

And of course the related radar loop from CASET. Locked on London :-)

So the snow squall that was supposed to set up west of #LdnOnt seems to have locked in over the city, at least for now. Some impressive snowfall rates here, on top of all the snow we already have. It's been a very snowy December here! #ONstorm