First the story about the abrupt changes now being observed in the Gulf Stream, the prevailing ocean current that has traditionally moved surface water from the tropical areas in the Atlantic ocean northward along the eastern coast of the USA, and into the North Atlantic ocean where it helps heat Northern Europe.
"...The theory is that freshwater melt from ice floats on salty sea water and creates a blockage in the warm northward flowing waters of the Gulf Stream. When the Gulf Stream shuts down, winter cold freezes the north Atlantic allowing cold air to penetrate much farther south, which has a reverberating cooling effect around the globe."This point is backed up in the blue area shown in the North Atlantic. The blue area is where ice is melting, leaving the surface water cooler as a result from the loss of ocean water circulation.
Next, the Psychrometric Chart showing the relationships between air temperature, relative humidity, amount of water vapor absorbed, and total energy of air under the full range of variation.
What brings these two together? If the prevailing Atlantic ocean current commonly known as the Gulf Stream is truly being disrupted as recent evidence suggests than it would mean that more of the sun's energy that lands in equatorial regions of the Atlantic area would have to migrate toward cooler areas away from the equator as heat energy stored in molecules of air traveling in the wind instead of as heat energy stored in water molecules within the ocean currents.
When heat travels in the ocean currents, the warmed water delivers heat in a northerly direction along the coastline. Regional wind patterns pick up the heat from the oceans and distribute the energy.
When the heat energy travels in the wind, the energy exists as a combination of an elevated temperature of the air and the amount of water vapor absorbed into the air. Hot humid air transfers more energy than cold dry air. And according to the Psychrometric chart, we can make two basic predictions about the future weather patterns we will see if the Gulf Stream is indeed disrupted. I am not proposing a theory as much as simply interpreting what the chart shows in plain sight.
1) Warmer air can absorb exponentially more water vapor than cooler air.
2) Warm humid air has a lower density than cold dry air. As air cools, it shrinks.
This means that in the seemingly random locations where warm humid air masses collide with cold air masses, there will be relatively larger amounts of snow or rain. and the resulting drop in barometric pressure will continue to pull in more surrounding air and source of precipitation.
It's a double-whammy. Higher average temperatures resulting from increased human activity not only lead to an increase in the amount of water vapor carried away from the equator region in the wind, the disruption in the Gulf Stream further increases the amount of water vapor carried away from the equator region in the wind. And all that extra absorbed water vapor has to fall out of the sky eventually.
So the megastorms are the new normal.