Meteorologists are closely monitoring yet another cross-country snowstorm on the way. Even though it will take a jog southward over the Rockies, the storm will then trek northward and aim at the Upper Midwest, just as many storms have done so far this winter.
The weather pattern feels like the movie "Groundhog Day" as Mother Nature seems to be exercising from muscle memory, according to forecasters, and that will start, in this case, with the storm rolling into the Pacific Northwest coastline.
"The storm will affect the Northwest with coastal rain and inland snow this weekend, prior to spreading moderate to heavy snow across the central and northern Rockies by early next week," AccuWeather Senior Meteorologist Brett Anderson said. "The Upper Midwest and northern tier of the Northeast will then take their turns with snow prior to the middle of the week."
A fresh blanket of snow will be a boon to skiing interests in the Wasatch Range and Colorado Rockies. A general 3-6 inches of fresh powder is forecast for the mountains with an AccuWeather Local StormMax™ of 16 inches.
All or most of the snow is likely to avoid Salt Lake City during Sunday night, but the Denver metro area may squeeze out a couple of inches from the storm on Monday.
Snow may struggle to bring more than an inch or two to parts of the Plains from eastern Colorado and western Nebraska to southwestern Iowa and eastern South Dakota during Monday.
Farther east, the storm should tap into Gulf of Mexico moisture, and snowfall rates are likely to ramp up once again.
Snowfall is likely to trend from 1-3 inches over northeastern Iowa and Minnesota to a general 3-6 inches over parts of eastern Wisconsin and central and northern Michigan from later Monday night through Tuesday.
In the swath from Chicago to Detroit, marginal temperatures are expected to play a significant role in limiting the amount of accumulation of snow, if any manages to stick at all. At this time, a mixture of rain and snow is forecast in these two metro areas with all rain to the south but more snow to the north.
If it were not for a reinforcing bubble of cold air expected to skip across the Great Lakes region from Sunday to Monday, the boundary between rain and snow would likely be much farther to the north as the coldest air from the Valentine's Day week Arctic outbreak will ease up early this weekend -- and a marked rebound in temperatures is anticipated.
As the storm crosses the Canada border from the northeastern U.S. on Tuesday and Tuesday night, it will encounter significant cold air and moisture with a large swath of 6-12 inches (15-30 centimeters) of snow forecast from central Ontario to southern Quebec and northern Maine. In these eastern areas, an AccuWeather Local StormMax™ of 16 inches (40 centimeters) is projected.
The early predictions of 1-3 inches and 3-6 inches of snowfall for New York state and central and northern New England from the storm are likely to be followed by a wintry mix and perhaps even a change to plain rain.
Another sweep of Arctic air will follow the storm next week.
The air next week is not expected to pack as much of a punch as the blast that spread from the northern Plains to the Eastern states to end this week; it is likely to be a larger and longer-lasting dose of cold air. It could play a role in the primary form of precipitation for any storm that comes along prior to the end of the month and could perhaps even lead to wintry precipitation in parts of the South.
Much of this winter, an area of high pressure has been a fairly permanent feature over the western Atlantic, and the jet stream has taken on a pattern to allow storms to move swiftly across the country.
"The combination of the warm and persistent western Atlantic high and the lack of a persistent area of cold high pressure near Greenland have played major roles in the track of most storms this winter," Anderson said.
A persistent area of cold high pressure near Greenland is referred to as a "Greenland Block" as it is also associated with a buckle in the jet stream and tends to slow the forward speed of storms as they approach the northeastern U.S. and southeastern Canada.
"The persistent high off the Florida coast has not only helped to pump warm air into the Southeast but has also forced storms to travel from the southern Plains and central Rockies toward the Upper Midwest," he added. "Since there has been no Greenland block, cold air can't linger for very long in the Northeast, and storms can't take a more southern track, slow down and strengthen along or just off the coast."
It is possible the pattern changes enough to allow the cold air to stick around and provide an opportunity for snow and force a late-month storm to take a more southerly track over the Eastern states. Time will tell.
Denver has been buried under more than the city's normal seasonal snowfall, 45.2 inches, by about a foot as storms have pushed inland over the West. Snowfall has been within a few inches of average in Minneapolis (40.9 inches) and Burlington, Vermont, (58.6 inches) with this season's worn winter storm path.
However, snowfall is well behind the typical pace in the swath from Washington, D.C., to New York City and Boston. Snow in part of the Interstate-95 corridor has been practically non-existent with only 0.3 of an inch in Philadelphia, which matches the total snow so far this winter for Muscle Shoals, Alabama, located in the northern part of the state and typically gets only a trace of snow each winter.