Monday, January 14, 2013

Dangerous Cold Arrives To Wrap Up January

To clear up any confusion, these are 850 Millibar temperature forecasts, in Celsius. That's 5000 feet above the ground, NOT the surface.

ECMWF 850mb forecast for Hour 192

ECMWF 850mb forecast for Hour 216
Dangerous cold is set to arrive in the nation to wrap up January, as the polar vortex moves south and drags anomalously cold air into much of the nation.

The above forecast shows the ECMWF model's latest 12z forecast. It depicts very cold air in the lower level of the atmosphere being dragged along south from the Arctic, as a very strong storm system moves north near the Canadian Maritimes in the bottom image. As I have been predicting for quite a while, recent stratospheric warming events have led to the release of cold air from the Arctic and the split of the polar vortex - semi-permanent low pressure in that region - to persuade cold air to push south. While the extent of such cold air has been in question, models are starting to build a consensus on a severe cold shock hitting the nation.

And this potentially-dangerous cold may persist well beyond January. Indications are that a continued cold spell will last through February, with the whole month likely ending below normal. Things are definitely looking good for cold starting in late January, stay tuned to The Weather Centre for continued daily updates on this developing information!



Logan said...

Are the numbers on the left the actual temperatures? Or departure from normal?

Anybody who knows, would be much appreciated! :)

Anonymous said...


Anonymous said...

I've been reading these posts the past few weeks and all I keep hearing about is brutal cold,now dangerous cold. Come on people, we used to get routinely down to the minus 20's all the time and it was no big deal. We've just been spoiled the past few years here in S.Ont. Now if this dangerous cold means minus 30's or colder than that's a different story. We haven't had those temps since January 1994 and even then it was only for 3-4 days. I say bring it on and we'll deal with it. Nothing to be afraid of here.

Anonymous said...

@Logan: I believe they are the true temperatures. All those dark blues and purples show temperatures 20-25 degrees Celsius below freezing, which is about -4 to -13 degrees Fahrenheit.

If this cold really does happen, it would be the coldest we've seen in 4 years, when it was -11.

Andrew said...

Logan: They are 850 millibar temperatures in Celsius.

Anonymous: Potentially below 20 degrees below normal.

Anonymous at 8:23: You'd be surprised. People die in the cold.

Anonymous at 8:44: They are 850mb temperatures in Celsius.