Tornado Alley (PROG)

[F6]

fuagf -- it's the increased Greenland ice melt -- the much fresher and thus lighter/less-dense meltwater floats at the surface, keeping the warmer but still heavier/denser saltwater brought to the area by the thermohaline circulation, specifically by the Gulf Stream, from remaining at the surface in contact with the air to be chilled enough to become dense enough to then sink as part of/to continue the thermohaline circulation (and accordingly add the heat to the air that helps keep the UK and Europe so relatively mild) -- the fresher water at the surface just turns to ice if sufficiently chilled, without ever becoming dense enough to then sink into/through the denser saltwater below it as part of/to continue the thermohaline circulation -- covering that, and more (together just one snippet from the ongoing climate research I have stashed):

Is ‘The Day After Tomorrow' Scenario Possible? Study Says Collapse Of Ocean Currents Could Reverse Global Warming Effects
October 11, 2015
http://www.techtimes.com/articles/93812/20151011/is-the-day-after-tomorrow-scenario-possible-study-says-collapse-of-ocean-currents-could-reverse-global-warming-effects.htm [with comments]

the study:
Competition between global warming and an abrupt collapse of the AMOC in Earth’s energy imbalance
Published online:06 October 2015
Abstract
A collapse of the Atlantic Meridional Overturning Circulation (AMOC) leads to global cooling through fast feedbacks that selectively amplify the response in the Northern Hemisphere (NH). How such cooling competes with global warming has long been a topic for speculation, but was never addressed using a climate model. Here it is shown that global cooling due to a collapsing AMOC obliterates global warming for a period of 15–20 years. Thereafter, the global mean temperature trend is reversed and becomes similar to a simulation without an AMOC collapse. The resulting surface warming hiatus lasts for 40–50 years. Global warming and AMOC-induced NH cooling are governed by similar feedbacks, giving rise to a global net radiative imbalance of similar sign, although the former is associated with surface warming, the latter with cooling. Their footprints in outgoing longwave and absorbed shortwave radiation are very distinct, making attribution possible.
http://www.nature.com/articles/srep14877

Could the Day after Tomorrow happen in real life? Southampton scientists say yes – sort of
October 11, 2015
http://www.dehlitimes.com/could-the-day-after-tomorrow-happen-in-real-life-southampton-scientists-say-yes-sort-of-461.html [no comments yet]

‘The Day After Tomorrow’ can be real
If global warming and a collapse of the AMOC occur simultaneously for a period of 20 years, the earth will cool instead of warm
2015-10-11
http://www.natureworldreport.com/2015/10/climate-change-can-make-the-day-after-tomorrow-happen/ [no comments yet]

Climate disaster looming, new model supports theory
October 11, 2015
http://www.babwnews.com/2015/10/climate-disaster-looming-new-model-supports-theory/ [no comments yet]

and, more broadly:

Welcome to a New Planet
Climate Change “Tipping Points” and the Fate of the Earth
Tomgram: Michael Klare, Tipping Points and the Question of Civilizational Survival
October 8, 2015
http://www.tomdispatch.com/post/176054/tomgram%3A_michael_klare%2C_tipping_points_and_the_question_of_civilizational_survival/ [also at "Climate apocalypse is here, now: Science fiction has become our new reality - Climatologists dismissed the science behind "The Day After Tomorrow." Eleven years later, it's not so improbable", http://www.salon.com/2015/10/09/climate_apocalypse_is_here_now_science_fiction_has_become_our_new_reality_partner/ (with comments)]