Pack your bags, autumn, because winter is moving in.
AccuWeather forecasters say an active storm track combined with a prolonged blast of cold air in the East will provide opportunities for many in the Appalachians, mid-Atlantic and Northeast to see their first snowflakes of the season -- and even though accumulations are not expected everywhere, some may need to dust off their shovels for the season.
Some portions of the Great Lakes have already experienced their first accumulating snow of the season as the lake-effect snow machine ran a little tune-up last week, dropping several inches of snow on some communities, including more than 11 inches in parts of northern Michigan. Lake-effect snow will kick into high gear again this weekend. However, while the Great Lakes region gets sprayed with snow, forecasters say Mother Nature will spread the wintry weather and bring some of the first snow of the season to a broader area over the course of a few days.
There are two main features to watch that could bring a general swath of snow, according to AccuWeather meteorologists. For some, this could mean at least a couple of inches for others, it may just be the first snowflakes of the year, perhaps mixing in with some rain.
The first system will move through the region Saturday and Saturday night. The same storm that was evolving into a snowstorm in the northern Plains and parts of Canada at midweek will continue to move northward toward the Hudson Bay in Canada, according to AccuWeather senior meteorologist Dave Dombek. "Energy will break off from the western and southern periphery of that storm and swing through the Great Lakes and Northeast," he said.
As it moves through the Northeast, more widespread rain and snow showers will break out across parts of the region. Dombek explained that the timing of this feature can make a big difference in the forecast.
"In areas that get precipitation during the day Saturday, it will mainly be cold rain showers that occur, with any snow showers confined to the highest elevations from the central Appalachians into upstate New York," Dombek said. "However, in heavier showers, there could be a brief burst of some small hail, called graupel, or partially melted snowflakes even at some lower elevations."
By later Saturday afternoon into Saturday night, as the sun sets, a change to more widespread snow could occur. This would likely bring accumulating snow to much of the Catskills, Adirondacks, Berkshires and Green and White Mountains and could even bring a small amount of snow to the Poconos and lower elevations from the upper Hudson Valley into interior New England.
The system will be moving along pretty quickly and is expected to exit the region by Sunday morning. With the fast-moving nature of the storm, even areas that receive accumulating snow are unlikely to get more than a slushy coating to an inch or two.
However, this time of year, roads have yet to receive winter treatment, and some roads at higher elevations could still turn quite slippery, even with minor snow accumulations.
Once the first system moves on, the next one will be right on its heels. A clipper storm, a quick-moving system with little moisture available, will race across the northern Plains on Saturday before diving southward toward the central Appalachians Sunday into Sunday night.
By Monday, energy from this storm will turn up the East Coast and may help to generate a new storm quickly enough to bring widespread accumulating snow to interior areas, even at lower elevations, and a portion of the I-95 corridor could end up getting the first flakes of the season.
Once again, the timing and track of this system will make a big difference in where snowfall occurs, and forecasters say there are a couple of different scenarios that could unfold.
"Lake-effect snow will be ongoing across the Great Lakes on Sunday. As energy from a clipper dives southward, rain and snow showers coming off the lakes could become even more widespread," said AccuWeather meteorologist Grady Gilman.
As the clipper crosses the Appalachians, a new area of low pressure could form somewhere near the East Coast. This is where multiple scenarios could come into play. One possibility is that the new system could form near or just inland from the coast and move northeastward, spreading a general light but likely accumulating snow through portions of the eastern Ohio Valley, mid-Atlantic and interior Northeast on Sunday night into Monday. Snowflakes could even reach places such as Washington, D.C., Philadelphia and New York City.
In a second scenario, a new area of low pressure may form much farther off the coast, triggering steadier rain and snow offshore. Only occasional rain and snow showers would occur in the Northeast on Monday should the system develop well offshore.
Even though flakes may fly early next week in parts of the I-95 corridor, no accumulating snow is currently expected. In fact, it would still be quite early for any accumulating snow in Philadelphia and New York City. The average date of the first measurable snowfall in New York City is Dec. 7, and in Philadelphia, it's Dec. 9. Measurable snowfall is an amount of 0.10 of an inch or greater.
On the other hand, in places like Pittsburgh or Albany, N.Y., accumulating snow arriving this weekend or early next week would be considered right on time. The average date of the first measurable snow in Pittsburgh is Nov.14. Albany's average date is Nov. 16.
After the taste of winter in the East this weekend into early next week, temperatures will moderate toward normal for mid-November, taking the edge off the chill and likely melting most of the snow that does fall.