ORIGINAL: Macclan5
1) May 16 2016 - "Frost warnings over night" for northern Toronto Regions (York Region - Newmarket Aurora Richmond Hill)
That would be Temperatures of slightly less than 0 degrees Centigrade / 32 degrees Fahrenheit.
Despite perceptions that Canada is North - Toronto is geographically south of Minneapolis St Paul / Seattle and other significant American cities (including all of North Dakota and Montana)
2) I am solely responsible for the weather.
I opened my backyard pool last Thursday. I am actually pleasantly surprised it did not snow.
If I open my pool it will be cold.
If I wash my car it will rain.
If I store my snow blower it will Blizzard
etc.
Seattle is the furthest north major city in the lower 48. It's on the same latitude with Montreal. Both the North Atlantic and North Pacific have counter clockwise currents that bring tropical water north along the eastern parts of those oceans. They make the Western US and Europe warmer than the same latitudes on the opposite sides of those oceans. The effect is more pronounces in the Atlantic where the North Atlantic is completely open to the Arctic around Greenland and Iceland. The Pacific has the comb of the Aleutians that allows less Arctic flow to get into the Pacific.
Because the Pacific off the west coast of North America is so deep, the continental shelf is right at the coastline, the tropical current stirs up cold deep water which comes up onshore along the West Coast. So ironically even though the region is warmed by the tropical current, the water at the shore is very, very cold. Surfers in Los Angeles usually wear wetsuits. You die of hypothermia very quickly off the Washington or Oregon coasts. Eastern North America has different terrain, the continental shelf extends several hundred miles out to sea which makes the coastal areas shallow and warmer.
Over the next few million years the Aleutians will become a peninsula, it's very active volcanically thanks to the Pacific plate getting subducted there. That will really crank up the moisture coming off the Pacific and may trigger a very long ice age. During the last 2 million years the world has been locked in ice ages with short inter-glacial periods. We're in one of those now. When the ice sheets grow, the oceans drop and the Aleutians turn into a peninsula. When that happens, all that tropical water collects in the Aleutians and isn't mitigated by any Arctic water. It produces a staggering amount of moisture.
During the last glacial period the west had some massive lakes. Lake Bonneville covered a large chunk of Utah and was 1000 feet deep. It was larger in surface area than Lake Michigan and much deeper. Lake Lahontan covered most of NW Nevada. The San Joaquin Valley in California was a giant lake. Southern California extending into Arizona and New Mexico was a verdant green paradise. The entire Puget Sound region was a giant fresh water lake. Then there was Lake Misoula which covers a large part of western Montana and the Idaho panhandle. That one was created by a big ice dam. Recent geology shows it drained and reformed multiple times. The floods when the dams broke crossed all the way across Washington State and down the Columbia River Gorge. In the Gorge the water was 1500 feet high. Rocks that originated in the Rockies have been found 1000 feet up in the Gorge.
Sorry, Geology geeking out...
Back kind of on topic, when those on the East Coast of NA want to blame something for freezing their *** off in May, blame the Atlantic Conveyor current.
[;)]
