I will use it as kind of an aside, ancillary tool, like the QBO. For instance, here is how I incorporated it last season:
While it is clear that the polar vortex should not be overly consolidated early on in the season, a major disruption is far from imminent, and in fact, quite unlikely any time in the near future. Climatology dictates that any early season warming of the polar stratosphere is relatively unlikely to propagate downward and result in a severe disruption of the vortex. There are also a couple of notable metrics that imply that the vortex should endure any early assaults. According to research conducted by Dr. Judah Cohen, the Eurasian Snow Cover Extent (SCE) and the Snow Advance Index (SAI), which are both measures of the snow build up in Eurasia, are positively correlated to subsequent disregulation of the vortex. This season, the SCE is merely near normal and below that of many recent seasons.
According to Cohen, the Snow Advance Index (SAI) is a paltry -1.4, both of which are suggestive that any major disruption of the polar vortex will occur later in the season rather than sooner. Thus its likely that any perturbations in the near future that aid in a wintery onset to the season are likely to be followed by a recovery and re-consolidation of the vortex as we approach the new year. However, there are mixed signals from Eurasia in the sense that during the month of October, a Eurasian snowfall dipole materialized that has been linked to a weaker polar vortex during the winter.
Courtesy of Judah Cohen
Although the piece also implies that such a phenomenon needs to be sustained throughout the month of November in order for the correlation to be viable, so this is something that bares watching.
Given the preponderance of evidence between extended guidance and an already modestly perturbed polar vortex, confidence is above average that there will not be a strong vortex from the middle portion of November and into the holiday season, although there will likely be periods of recovery. It will ultimately persevere.
This outcome is also supported by the analog composite, which in hindsight accurately predicted one of the warmest months of October on record throughout the northeast.
Note that while I incorporate it into my conceptualization of how the season will evolve, its not the center piece of my outlook. I think it has value like any other tool does, but it was likely misused several years back, when it first came out and its value was probably overstated.