mostly rain / sleet now in metro west .. mby in Shrewsbury at about 420' got ~3" of slush. Driving around looks like above ~600' accumulations picked up. Took a weenie drive to the highest spot in town at ~750' and look like easy 5"-6" up there with roads still slushy.
looking at the 18z NAM (for example), you can see drier air getting advected in from the east as the low lvl centers begin to ramp up / tighten. Can see this on the radar a little bit too as the precip hasn't been able to advance much past a TAN - BOS - LWM axis. Probably why the sleet is over-performing right now haha
This time of year, the correlations to those indexes and weather are weaker. Wavelengths are shorter, easier to get those cut-offs and coastal bombs despite the teleconnections values. Also index value isn’t as important as rate of change.