Northeast Could See Snow As Spring Arrives (FORECAST)

Jon Erdman
Published: March 18,2015



 

Spring, the vernal equinox, officially arrives at 6:45 p.m. EDT Friday. We don't need to remind anyone of the magnitude of the winter folks in New England and other parts of the Northeast have faced.
(MORE: New England's Record-Smashing Snow Season)
While Boston's seasonal snow record has been well documented, there are also a couple of snow cover longevity notables from this winter that you may not have heard about:
- Newark, New Jersey: Record 45 straight days with at least 1 inch snow cover (ended March 9).
- Syracuse, New York: Record 19 straight days with over 2 feet of snow cover (ended March 9).
- Machias, Maine: Set daily snow depth records from Jan. 28-March 11, then again from March 16-17 (36 inches as of March 17).
So it only stands to reason that snow is on the table as spring arrives. Here's what we know now.

Low pressure near the Northeast seaboard may wrap moisture into lingering cold air to wring out wet snow for some on Friday and Friday night.

The Ingredients

In the wake of yet another snowmaker for eastern Maine and parts of Atlantic Canada, fresh, cold air has been dragged into the Northeast.
(FORECAST: The Cold Returns)
Disturbances in the northern (polar) and southern (subtropical) jet streams and associated moisture will swing into the Northeast on Thursday.
In response, an area of low pressure will spin up off the Northeast seaboard Friday and Friday night. A reinforcing arctic cold front will then sweep into the Northeast Saturday.
Before you become concerned that this sounds like another big Northeast snowstorm, there are several aspects that mitigate this threat:
- The cold air becomes more "stale" by Friday, thus near-surface temperatures may allow for some melting of falling snow.
- It's also late March. With the sun higher in the sky, that would also add several degrees of warmth to an air mass compared to what we would see in January or February.
- The offshore low-pressure system isn't expected to become strong. Therefore, strong winds will not be an issue.
- The reinforcing arctic cold front most likely won't arrive to combine with the offshore low until Saturday, when the low will be moving into Atlantic Canada. This will limit the potential for heavy precipitation over the northeastern U.S.

Friday's Forecast

Friday Night's Forecast

Snowfall Forecast

The Forecast

A couple of days out, forecast uncertainties typical in virtually all snow events still exist.
A low track more directly east would take most of the precipitation out to sea faster than a track closer to the Northeast coast.
Furthermore, it remains to be determined where the rain/snow line, that zone delineating where precipitation falls mainly as rain vs. mainly as wet snow, sets up.
For now, here is our forecast timing:

• Thursday night: Some wet snow may fall in the northern Appalachians and a few flakes may push as far north as parts of southern Pennsylvania overnight. There will be a steady rain south of the Mason-Dixon Line.
• Friday: Wet snow is possible from the Appalachians to the Hudson Valley, Long Island and southern New England. Some slush buildup on roads is possible for the morning and afternoon commutes.
• Friday night: Wet snow continues particularly from southern New England westward to northeast Pennsylvania, including the New York City area. A little snow is also possible in Upstate New York and parts of northern New England.
• Saturday:  Expect additional snowfall over eastern New England as an area of low pressure passes by just offshore. Meanwhile another area of snow will occur over upstate New York and Vermont as an arctic cold front approaches.

Here is our latest outlook on snowfall amounts:

• Highest accumulation potential: 3 to 6 inches possible from central and eastern Pennsylvania through parts of New Jersey, southeastern New York (including New York City) and into Connecticut and Rhode Island. Another area of 3 to 6 inches (possibly more) is expected over the eastern half of Maine on Saturday.
• Lesser accumulation: Interior New England, upstate New York, I-95 corridor south of Philadelphia. Some snowfall may initially melt on roads Friday.

(FORECASTS: Boston | NYC | Philly | Baltimore | Washington)

Average date of last measurable snow of the season, snow that typically falls after March 20, and the percent of the season's snow that falls after March 20.

Perspective: The Last Snow of the Season

If you're truly sick of snow, you're probably wondering when the last snow of the season occurs.
While every season is different, the season's last accumulating snow typically falls from late February as far south as the Nation's Capital, to late March in southern New England, to April in Maine.
In snow-weary Boston, it's par for the course to pick up another 3 to 4 inches of snow after March 20. Bangor, Maine can expect another 7 to 8 inches of spring snow, comprising roughly one-eighth their season's average snowfall.
Last spring, 0.3 inch of snow fell in Boston on April 16. Boston's previous record snow season featured an April 7-10, 1996 dumping of 7.3 inches of snow.
Of course, we'd be remiss not mentioning the April Fools' Blizzard of 1997, when 25.4 inches of snow in just 24 hours paralyzed Boston and parts of southern New England.
Check back with us at weather.com and The Weather Channel for updates to this forecast as the week goes on.

MORE: Boston's Snow Misery 2015