The final chapter of Winter Storm Regis will deliver a swath of snow from parts of the New England into Monday as a nor'easter tracks well off the East Coast. Portions of eastern Massachusetts and Downeast Maine are forecast to see the heaviest snow amounts from Regis.
The National Weather Service has issued winter storm warnings and winter weather advisories from Long Island to southeast New England and Downeast Maine. Snowfall totals of 6 inches or more are likely in parts of eastern New England, with some locations locally seeing up to 10 inches of snow.
Regis first brought snow to parts of the Rockies, including Denver, Thursday into Friday. Light snow accumulations were reported from Regis on Saturday in the far northwest suburbs of Washington, D.C. and parts of the central Appalachians through Sunday. Light snow then grazed the Baltimore to Philadelphia corridor and points east across the Mid-Atlantic Sunday night. A recap of snowfall reports so far is at the bottom of this article.
RELATED: February winter weather across the US
February winter weather across U.S.
Winter Storm Regis takes aim on East; Heaviest snow expected in New England (Forecast)
A pedestrian walks through Washington Park as light snow falls on Tuesday, Feb. 16, 2016, in Albany, N.Y. A mix of snow, sleet and freezing rain made driving conditions dicey for commuters across upstate New York, with winter storm warnings and hazardous weather advisories posted throughout the state. (AP Photo/Mike Groll)
Harry Henneman clears snow from the front steps of his daughter's house Thursday, Feb. 18, 2016, in Truckee, Calif. A storm packing rain and high winds downed power lines, toppled trees and delayed flights across California, bringing back winter weather after several days of record-heat. In the Sierra Nevada, the winter storm dropped 1 to 2 feet of light powdery snow late Wednesday, adding to a snowpack that could ease but not end drought conditions when it melts in the spring. (AP Photo/Marcio Jose Sanchez)
One of the 19 stainless steel statues of the Korean War Veterans Memorial is covered with snow in Washington, Monday, Feb. 15, 2016. Bitter cold was replaced by snow, sleet and rain Monday in the mid-Atlantic states and the South, but many residents were able to hunker down at home with federal offices and many businesses closed for Washington's Birthday. (AP Photo/Carolyn Kaster)
A vistor to the Washington Monument walks past flags flying a half-staff in honor of Supreme Court Justice Antonin Scalia on a wintry Presidents Day holiday in Washington, Monday, Feb, 15, 2016. (AP Photo/J. David Ake)
People survey damage to a business off Mississippi Highway 18 in Sylverana, Miss., Monday, Feb. 15, 2016, after severe weather affected south Mississippi. No injuries were reported in the storm. Officials are investigating reports of at least two possible tornadoes that accompanied a line of thunderstorms across central and southern Mississippi Monday. (Ryan Moore/WDAM-TV, via AP)
Frost on a window forms a heart-shaped pattern on Friday, Feb. 12, 2016, in Falmouth, Maine, where the early morning temperature dipped below zero. More cold weather is forecast for the Valentine's Day weekend in New England. (AP Photo/David Sharp)
A bus window is covered by snow and ice, Sunday, Feb. 14, 2016, in Evanston, Ill. Snow has now overspread nearly all of the Chicago Metro area early Sunday afternoon and is expected to continue into the night before ending. (AP Photo/Nam Y. Huh)
People are bundled up as they walk in cold weather, Sunday, Feb. 14, 2016, in the Queens borough of New York. Bitter temperatures and biting winds had much of the northeastern United States bundling up this weekend. (AP Photo/Mark Lennihan)
A bare tree stands in a snowy field near Freeland, Md., Tuesday, Feb. 9, 2016. The mid-Atlantic region awoke Tuesday to a mix of rain and snow. The weather service issued a winter weather advisory in the region and expected the mix to change over to snow and fall occasionally during midday hours, with rain mixing in during the afternoon south of Baltimore. (AP Photo/Patrick Semansky)
Two women run through a snow flurry Tuesday, Feb. 9, 2016, in Nashville, Tenn. (AP Photo/Mark Humphrey)
A passenger waits in the snow to board a bus at Kennedy Plaza in Providence, R.I., Monday, Feb. 8, 2016. Massachusetts, Rhode Island and eastern Connecticut, could see winter storm conditions with an accumulation of 4 to 8 inches. The heaviest snowfall is expected during Monday's morning commute through the afternoon. (AP Photo/Stew Milne)
Kevin Lord, of Sagamore Beach, Mass., braves near hurricane-force winds to inspect storm erosion on Monday, Feb. 8, 2016, along a beach near his home in Bourne, Mass. (AP Photo/William J. Kole)
Jeremy Kincaid clears a sidewalk with a snowblower after a snow storm Friday, Feb. 5, 2016, in Derry, N.H. The storm was New Englandâs biggest snowstorm so far this season, coming two weeks after a massive blizzard engulfed much of the Eastern Seaboard but largely spared Boston and points north. (AP Photo/David Goldman)
Democratic presidential candidate Hillary Clinton departs a campaign stop during a snow storm, Friday, Feb. 5, 2016, in Manchester, N.H. (AP Photo/Matt Rourke)
A snow covered playground is bathed in pink light at sunset before a town hall meeting with Republican presidential candidate Sen. Ted Cruz, R-Texas, at the Lancaster School in Salem, N.H., Friday Feb. 5, 2016. (AP Photo/Jacquelyn Martin)
WASHINGTON, DC - FEBRUARY 13: Ai Koid, 25, fights gusty wind chills and snow while walking to the bus stop at Dupont Circle in Washington, D.C., February 13, 2016, to catch a bus to New York. (Photo by Astrid Riecken For The Washington Post via Getty Images)
Andrew Story clears a sidewalk with a snowblower after a snowstorm Friday, Feb. 5, 2016, in Derry, N.H. The storm was New Englandâs biggest snowstorm so far this season, coming two weeks after a massive blizzard engulfed much of the Eastern Seaboard but largely spared Boston and points north. (AP Photo/David Goldman)
A deicing team prepares a commercial jet for safe flight during severe weather at Denver International Airport, in Colorado, early Tuesday, Feb. 2, 2016. A powerful winter storm has shut down highways in eastern Colorado, closed many schools and slowed down traffic at Denver International Airport. (AP Photo/Brennan Linsley)
Looking southwest from Reno about 20 miles away, clouds obscured the top of Slide Mountain on Monday, Feb. 1, 2016, where the Mount Rose ski resort received 18 inches of snow the day before. (AP Photo/Scott Sonner)
A plow removes snow during severe weather at Denver International Airport, in Colorado, early Tuesday, Feb. 2, 2016. A powerful winter storm has shut down highways in eastern Colorado, closed many schools and slowed down traffic at Denver International Airport. (AP Photo/Brennan Linsley)
Students on the campus of Northern Arizona University navigate through blustery weather in Flagstaff, Ariz., Monday, Feb. 1, 2016. A winter storm dropped snow on the region, closing schools and making travel difficult. (AP Photo/Josh Biggs)
Here is our latest snowfall forecast followed by the timing for this final phase of Regis.
Regis Forecast Impacts: How Much Snow?
Best potential for 6 inches of snow (locally up to 10 inches): far eastern Long Island, southeast Massachusetts (from near Boston southward), Rhode Island, far southeast Connecticut and Downeast Maine.
Light snow amounts (less than 3 inches): New Jersey and the New York City metro area.
Wind could cause power outages: Some gusts up to 40 mph are possible in southeast Massachusetts into early Monday, which, coupled with accumulating wet snow, may lead to sporadic power outages and a few downed limbs. Coastal flooding should be minimal from this system.
Regis Forecast Timeline
The strengthening offshore low tracks from off Nantucket Island to Atlantic Canada.
Snow, along with moderate winds, spread from Long Island to southeast New England into eastern Maine and Atlantic Canada.
Wintry driving conditions are possible at least for the Monday morning commute in eastern/coastal New England. Any untreated roads may remain snow-covered into Monday evening, as well.
Travel impacts include slick travel along portions of the I-95 corridor from New London to Boston through Monday morning.
Here are some of the top snowfall totals by state from Regis in the East, so far.
Maryland: 4.5 inches in Oakland
North Carolina: 6 inches in Newfound Gap (elevation of 5,049 feet)
Virginia: 4 inches near Linden
West Virginia: 7 inches near Cherry Grove
Storm-prone Interstate 80 was once again shut down due to snow and wind from Rawlins to Laramie, Wyoming Thursday night into early Friday, but has since reopened.
Snow from this system impacted the Rockies and central High Plains, with some snow inching across the state of Kansas early Friday.
Some top snowfall as of Friday night include:
18.2 inches at Rabbit Ears, Colorado.
16.9 inches at Tower, Colorado.
13.0 inches near Boulder, Colorado.
10.5 inches at Aspen Springs, Colorado.
0.3 inches near Milberger, Kansas.
Why Was this Such a Difficult Forecast
Nor'easters are often a forecast challenge, but this particular system gave meteorologists whose task is to interpret various computer forecast model guidance into forecasts a headache.
One of the reasons for the uncertainty was a complicated upper-level pattern.
It wasn't simply just one upper-level system giving birth to offshore low pressure, but rather a complex interaction of (A) a digging shortwave trough from the Rockies, (B) a remnant circulation from a stalled gyre of low pressure over the Upper Midwest and (C) a sharp southward dip in the jet stream nosediving southeastward from Canada.
The other challenge was simply that it's late in the "snow season". Air masses by early spring are typically only marginally supportive for snow in lower elevations.
Furthermore, the lack of snowcover thanks to the recent warmth since February has allowed ground temperatures to remain rather warm, which would serve to, at least initially, melt the first flakes of snow hitting the ground.
Speaking of recent warmth, consider what we've seen recently in the East: