Understanding Global Warming's Effect On Weather

The arctic is warming faster than other parts of the planet.  This is having an effect on weather. 

It is well documented that the Arctic is warming at 2 to 4 times the global average rate (read here and here).

This decreases the temperature difference between the Equator and the Arctic, which decreases the driving force for the Jet Stream winds. The weakened driving force allows the jet stream to wallow around, just like a river that slowly meanders back and forth when it hits an area with only a slight elevation change (think flat). The image is similar to how a sailboat flounders about when the keel is pulled up: moving at the mercy of the wind instead of challenging it. In the same way that healthy arctic ice is linked with a strong, healthy jet stream that tracks relatively straight and true around the earth, so too a strong, deep keel is linked to a sailboat that tracks straight and true.

It is the melting Arctic ice that is causing the jet stream to lose its “keel” and change from tracking straight around the globe from West to East, and instead meander aimlessly. Remembering that the temperature of ice is 0°C or colder, as long as there is ice there are stable, constant, cold temperatures in the Arctic. Once the ice is gone, the water is free to warm up to any temperature above 0°C. The fundamental cause of the decreasing temperature difference between the Equator and the Arctic is melting Arctic ice, but the reason for the rapid warming is the changing albedo from reflective ice to absorbing ocean water.

• A meandering jet stream allows deep troughs and ridges, allowing some areas to get unusually warm while other areas become unusually cold (read here, here, and here) 
• A slowing, meandering jet stream is associated with weather patterns persisting for longer periods than they would with a jet stream that blows more strongly and directly in a West-to-East direction. A few hot days can turn into a heat wave, a period of rain can turn into a flood, and a period of dry weather can turn into a drought (read here). 
• The Jet stream may shed high-pressure systems that act like blocking highs. This is part of what is believed to have caused SuperStorm Sandy and Hurricane Florence to turn into the East coast of the US rather than assuming a northward trajectory that would have kept them away from the East Coast of the US (read here and here).

 I've posted before about these issues.