In the short term: A wave of low pressure is now moving northeast towards the Mid-Atlantic region with plain rain already falling in the DC metro region. As the precipitation advances farther north, it’ll encounter slightly colder air at the surface and the northern and western suburbs of Philly and New York City will be right near the rain, freezing rain, sleet, snow boundary zone throughout this storm. As a result, a wintry mix is likely in these suburban locations from later this evening into early Wednesday and small accumulations of ice and/or snow are quite likely. The starting time for the precipitation in the Philly metro region is about 8-10PM and from around 10PM to midnight near the NYC metro region. Temperatures tonight will fall to near freezing in many of the suburbs and icy spots are likely. Stay tuned as this is still a tricky forecast.
In the medium term: It’ll remain moderately chilly for the rest of the week following yesterday’s cold frontal passage, but big changes are in store for the overall temperature pattern beginning early next week. A major sudden stratospheric warming event has produced significant changes in the overall weather pattern from the North Pole to the mid-latitudes and this will result in much colder weather pattern for the central and eastern US beginning early next week. As the stratosphere has warmed up in the northern latitudes in recent days, there has been, in turn, compensating much colder air shifting into the troposphere and soon that cold air will be displaced to the mid-latitudes of the central and eastern US. It appears that this change to a much colder weather pattern around here will last for awhile. In fact, the effects of this major stratospheric warming event may not reach its peak until later this month or even during the month of February. The change will also no doubt increase our chances for snow during the second half of the month.