Winter Storm Regis has dropped more than a foot of snow across parts of the Rockies, but this is only just the beginning for this late season winter storm. Regis is forecast to progress east, bringing snow into the central Appalachians later Saturday, before redeveloping as a nor'easter later this weekend.

By Sunday into Monday, locally heavy snow remains possible over parts of New England and the mid-Atlantic states, just as spring officially arrives this weekend.

(MORE:Latest Regis Impacts/News)

Regis was named just after midnight Friday when winter storm warnings were issued for the Denver metro area, meeting The Weather Channel population requirement for named winter storms. Snow has since wound down across the area.

(MORE:How Winter Storms are Named)

East Coast Nor'easter

If it wasn't for the near record-setting snowfall from Winter Storm Jonas, New York's Central Park would be on pace for its least snowy season in 14 years. Only 4.8 inches of snow has fallen outside of that late January snowstorm.

It only stands to reason, then, that a chance of snow moves into the East this weekend.

(MORE:The Science Behind the First Day of Spring)

As can sometimes happen in East Coast snow events, there remains a sizable degree of uncertainty this far out.

Snow Starts Saturday

Colder air will gradually work its way into the East during the first half of the weekend, a pattern change led by a gyre of low pressure is slowly spinning down over the Great Lakes.

This will allow for a swath of generally light snow and mixed precipitation to spread from the Ohio Valley early Saturday, toward the central Appalachians and Mid-Atlantic during the afternoon and evening.

Saturday's Forecast

(Blue indicates snow, while pink is a wintry mix and rain is shown in green.)

A portion of West Virginia and northwest Virginia may see as much as much as 2 to 4 inches of snow by Saturday evening, as winter weather advisories have been issued for this region. Elsewhere, from parts of Kentucky, southern Indiana to southern Ohio, snowfall amounts should be limited to less than an inch.

The forecast into the Mid-Atlantic is a bit more tricky, as temperatures may initially be too warm for snow to fall and accumulate. However, into the evening, as colder air works in, a narrow band of snow is possible across portions of northern Virginia, Maryland, Delaware, southeast Pennsylvania and New Jersey.

(FORECAST: D.C. | Philadelphia | Atlantic City)

At this point, while significant accumulations are not anticipated here, a couple inches of snow cannot be ruled out.

Forecast Remains Complicated

One of the reasons for the uncertainty is a complicated upper-level pattern. Exactly how the interaction of (A) a digging shortwave trough from the Rockies, (B) a remnant circulation from the aforementioned Midwest gyre and (C) a sharp southward dip in the jet stream nosediving southeastward from Canada will help determine how this potential East Coast system evolves.

In response to all this, low pressure should develop and intensify somewhere near or off the East Coast Sunday and Monday.

The $64,000 question then is, "Where will the center of low pressure track?"

The Setup This Weekend Into Monday

A closer track to the East Coast would bring a better chance of heavy snow, or perhaps even a period of rain closer to the coast, from parts of Maryland to New England, including a sizable swath of the heavily-populated I-95 Boston to Baltimore corridor.

However, a track farther offshore might confine the heaviest snow closer to coastal New England, leaving lighter snow for most other Northeast locations.

Here is our general forecast thinking for Sunday into Monday:

Best potential for at least 6 inches of snow: Eastern New England, from eastern Long Island to Downeast and northern Maine.Light to moderate snow totals most likely, but can't completely rule out locally heavy snow: I-95 corridor from New York City metro to Maryland.An inch or two at best most likely: Upstate, central, western New York; central, western Pennsylvania.

Winter storm watches have been issued by portions of eastern Massachusetts and all of Rhode Island, where confidence of potentially heavy snow is the highest. Some additional light snow may continue into Sunday to the west across the Appalachians, possibly resulting in total accumulation of near or just over 6 inches.

(FORECAST:Boston|New York|Philadelphia|Bangor, Maine)

Winter Weather Alerts

(Alerts issued by the National Weather Service.)

Our latest forecast maps for Sunday and Monday are shown below.

If the snowier East Coast scenario would come to pass, this could pose travel headaches including flight delays out of some major Northeast hubs and a challenging Monday morning commute in parts of New England.

(MAPS:10-Day Forecast Highs/Lows|Weekly Planner)

Fortunately, this system should move rather quickly, either out to sea or into Atlantic Canada by Monday night.

Sunday's Outlook

(Areas in pink denote either rain or snow may fall. Areas in blue denote where snow may fall.)

Monday's Outlook

(Areas in pink denote either rain or snow may fall. Areas in blue denote where snow may fall.)

First Phase of Regis

Storm-prone Interstate 80 was once again shut down due to snow and wind fromRawlinsto 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.

Big Change in the East After a Warm Stretch

If you needed any more reminders of how changeable the weather can be this time of year, this is your exhibit A.

A man rollerblades near the Bethesda Terrace in Central Park, Manhattan, New York City, March 9,2016 as people take advantage of the warm weather in the city.

(TIMOTHY A. CLARY/AFP/Getty Images)

Consider what we've seen recently in the East:

A record warm December-February in New England, and one of the warmest on record in much of the East.A rash ofsevere thunderstorms as far north as Maine in late February.The warmest temperatures so early in the season on March 9in the Northeast, including low 80s in Albany, New York.Through March 16, this has been the least snowy season-to-date in both Albany, New York (10.3 inches), and Binghamton, New York (22.3 inches).

Check back with us at weather.com for the latest on this potential storm and any likely forecast changes ahead.

MORE ON WEATHER.COM: Winter Storm Regis (PHOTOS)