The week’s first winter-like storm is passing just south of Long Island this morning. It is responsible for snow accumulations for the interior Northeast, while the coastal Northeast and Mid-Atlantic states have so far and will continue to just see rain. However, we can expect a different outcome for this next system. While still days away, guidance is beginning to converge on what could be the first widespread snow event for the Northeast this season.
Let’s first talk about the set up for this next storm. To understand the many surface features, we have to look at the upper levels. A digging shortwave trough is the culprit behind both storms this week as it makes its way across the US. In the last 24 hours, this trough has deepened and currently stretches down into TX; it’s also the cause of frigid temperatures for the Central Plains. Within the next 24 hours, this will become a cutoff low, essentially detaching itself from regular western flow. As its own independent circulation, this cutoff low will move slowly northeastward as it continues to strengthen. Out ahead of this upper level system is where the surface low, and thus the storm many will experience, will form.
Different from our current storm, this next surface low is expected to hug the coast more closely, a factor that would generally mean a rainier event for the coastal Northeast. The biggest differences here though will be colder temperatures and an overall stronger storm. The passage of this last cold front has introduced below-freezing low temperatures as far south as VA and TN. This will set up a much snowier outcome, one which most models have converged upon in the latest 00z and 06z runs.
As the storm makes its way up the East coast on Thursday, we’ll get the first taste of wintry precip as far south as KY and VA. Snow is much more possible further west, mainly for states along the Mississippi River. Along the coast, temperatures should still be mild enough for almost completely rain. The states in between (VA, TN, OH, IN) can expect a dangerous icy mix, with sleet and even freezing rain possible. These specifics are much harder to forecast this far out, but with temperatures so close to freezing at the surface, some ice accumulation can be expected.
Further north, more precip will turn completely over to snow as temperatures lower. Along the coast and the I-95 corridor will likely remain rain for cities like Philadelphia and NYC. Due to colder temperatures ahead and behind this storm, snowfall will still reach further than it has yet this season, bringing light accumulations as far east as Putnam and Orange counties in NY and the western half of MA. As the storm continues northward, snow will be brought further and further to the coast. Areas between rain and snow can expect a wintry mix, with rain, snow, and sleet possible. This will cause slippery conditions and make roadways dangerous, even without any significant accumulation.
As always, stay tuned to WeatherOptics for updates regarding this end of the week storm as more data comes in.