Meteorologists are watching an exceptionally early disruption of the polar vortex in the first week of November, a development that could set a record for the earliest breakdown and displacement of the system dating back to the 1950s. Judah Cohen said it is one of the most, if not the most, surprising behaviors he has ever witnessed from the polar vortex.
The latest forecast shows the winds around the polar vortex slowing sharply and possibly reversing direction by the first week of November. If that happens around Nov. 4 or 5, it would beat the previous seasonal mark of around Nov. 28 by roughly three weeks, which is why the El Niño November Weather Forecast has drawn close attention now.
The polar vortex is a massive circulation of strong winds spinning around the Arctic high above in the stratosphere. When it weakens, stretches, or splits, it can reorganize the jet stream and send pockets of frigid air south. That is the part meteorologists are watching, because a disruption this early could change where cold air ends up and whether New England feels the effect.
The reason the forecast stands out is that the upper atmosphere is already showing sudden stratospheric warming, with temperatures surging as much as 50 to 70 degrees in just a couple of days high in the sky. Scientists say the record-warm El Niño is pushing pockets of intense surface heating north and upward into the atmosphere, where they form Rossby Waves that can crash into the polar vortex and make it weaken and sag.
That is where the forecast runs into a wall of climate logic. A very strong El Niño would usually make the polar vortex more stable heading into winter, not less. But these Rossby Waves are arriving at an unusual time, and statistically the vast majority of them show up during January and February. Early November is almost unheard of for that kind of setup, which is why Cohen called the behavior so startling.
For weather and climate records, that is really unheard of. The next thing to watch is whether the winds actually reverse around Nov. 4 or 5, because that would confirm an extraordinarily early breakdown. What it would mean for specific places is still unclear, but if the polar vortex does weaken further, the jet stream could shift enough to pull Arctic air south in some regions while leaving others milder.
