Threat Analysis: Weekend winter storm
A well discussed storm system — with winter weather potential — is heading towards the Northeast US this weekend, in the wake of a brutally cold airmass associated with the polar vortex in the troposphere. This storm, however, will come with a vast amount of warm air advection — which occurs when warm air moves in multiple levels of the atmosphere. In this case, southwesterly winds are driving the storm system towards the Northeast as the polar vortex departs.
The resulting storm system will be one of transition, with a cold airmass in place to start, followed by a moist and warm airmass as the storm begins its departure. The transition itself will occur with quite a bit of complexity, and interior locations are likely to see a impactful winter storm on Saturday, particularly in the morning hours. Nearer to the coast, a change to rain should occur relatively quickly, alleviating widespread impacts.