This story has been replaced by "DC, Virginia, Maryland Midweek Snowstorm," published Sunday, Mar. 3, 2013.
A wintry system that will make a cross-country tour this weekend has the potential to develop into a powerful and very disruptive storm along the East Coast next week.
Northwest and Plains
The storm will track into the Pacific Northwest and British Columbia tonight bringing a modest dose of rain and mountain snow.
Some of the early weather-related problems with the storm in the Northwest this weekend will be drenching rain along the coast and snow dipping to pass levels. As with many storms that bring snow to the high country and shifting snow levels in the Northwest, there is a risk of avalanches.
In fact, most of the life of this storm as it traverses the Northwest through Sunday, then the northern Rockies and central Plains into early next week will not be blockbusting news.
Through this point, the storm will tend to bring travel disruptions typical of the winter months with a swath of light to moderate snow. On a positive note, the storm will provide some moisture to a needy area. (States in the path of the modest storm to this point include, but are not limited to, Washington, Oregon, Idaho, Wyoming, Montana, North Dakota, South Dakota, Minnesota, Nebraska, Iowa and Missouri).
Midwest and South
However, toward the middle of next week (March 4-5), as this storm crosses the Mississippi River, changes taking place in the upper atmosphere will favor gradual strengthening to the Atlantic coast.
Moisture will begin to feed into the storm from the Gulf of Mexico, and we are likely to start to see heavier precipitation in the form of snow over the Ohio Valley states and snow, rain and thunderstorms to parts of the South and the mid-Atlantic. (States likely to be most involved at this point include Illinois, Indiana, Ohio, Kentucky, Tennessee, Mississippi, Alabama, Georgia, South Carolina, North Carolina, Virginia and West Virginia).
Once the storm reaches the Atlantic coast Wednesday into Thursday (March 6-7), conditions at most levels in the nearby atmosphere and well away from the storm throughout North America could lead to rapid development near the coast. At this point, the storm could become a dangerous system for parts of the mid-Atlantic, leading to significant travel disruptions and severe coastal flooding from the Outer Banks to Atlantic City, N.J.
According to Chief Meteorologist Elliot Abrams, "There may be similarities to a storm which affected much of the same area around March 6, 1962."
This graphic is for illustration purposes of one scenario of what the jet stream pattern may resemble March 6-7, 2013.
Storm Scenario Number 1, Track & Impacts
As the storm reaches the East Coast, we now have two potential scenarios. The first sends the storm eastward off the mid-Atlantic coast, leading to a substantial snowstorm from the central Appalachians into the western half of Virginia, western Maryland and the high spots of western North Carolina.
Snow mixed with rain would occur across Washington D.C., Baltimore, and Richmond cutting down on the snow accumulations, but still allowing for substantial travel problems. Significant coastal flooding would be possible from the Outer Banks of North Carolina to Long Island with a windswept rain affecting the mid-Atlantic coast.
This scenario generally keeps the heaviest precipitation to the south of New York City, Boston and Philadelphia.
Storm Scenario Number 2, Track & Impacts
The second and more dangerous scenario has the storm emerging off the East Coast with rapid strengthening taking place. A stronger storm would more likely take a northward turn, spreading heavy snow and potentially dangerous wind gusts into more of southern New England, including Boston and New York City.
The eventual track from this potential atmospheric bomb will determine whether or not portions of the mid-Atlantic and southern New England have a foot or more of windswept snow, hurricane-force gusts, power outages, coastal flooding, flooding rain and travel mayhem with a storm hugging the coast or another non-event with the storm heading out to sea. (States on the bubble for a major storm or a near-miss include North Carolina, Virginia, Maryland, Delaware, Pennsylvania, New Jersey, New York, Connecticut, Rhode Island and Massachusetts, as well as the District of Columbia).
At this point, it is too early to alter plans, but rather something to keep an eye on and perhaps come up with "Plan B" in case a major blizzard unfolds and wallops areas from Richmond and Washington, D.C., to Philadelphia, New York City, Hartford, Providence and Cape Cod Wednesday into Thursday.
AccuWeather.com Meteorologists will continue to monitor the situation over the weekend as the system we're watching is just moving into the Pacific Northwest. Once on land, our forecast tools will zone in on a solution.
We will then have more information to pass along to followers on AccuWeather.com related to the timing of the precipitation and amount of snow and rain, and the severity of thunderstorms, wind, seas and coastal flooding.
People and officials in coastal areas may want to review emergency procedures for the chance that the storm overachieves, as we have suggested it could, and makes the northward turn up the coast.
Thumbnail graphic illustration by Photos.com
This story was originally published at 10:30 a.m. EST, Thurs., Feb. 28, 2013 and has been updated at 1:15 p.m., Sat., Mar. 2. More storm-specific graphics and additional stories on the situation forthcoming.