At a Glance

Northeast snowstorms can be difficult to forecast.Winter Storm Quinn brought snowfall differences of 20 inches in less than 20 miles for some.

Winter storms in the Northeast can be challenging to forecastand was no exception. One of the challenges with Quinn was the tight snowfall gradient toward the coast.

(MORE: )

This was especially clear in the snowfall totals reported in the New York City area.Franklin Lakes, New Jersey,measured an impressive 24 inches, or 2 feet, of snowfall from Winter Storm Quinn. However, less than 20 miles away, Central Park received just 3.2 inches of snowfall.

Contour on the map indicates snow cover as of 7 p.m. Jan. 7, 2018.

In Connecticut, about 4.5 inches of snow fell in Darien, but just over 15 miles to the northin Ridgefield about 19 inches of snow accumulated.

Farther east in Massachusetts, a snowfall gradient of over 10 inches was reported in about 8 miles: Weymouth recorded 2.2 inches of snowfall, while Milton measured 13.8 inches.

How could there be such a large difference in snowfall over such a small area?

One reason is where the heavy bands of snow developed Wednesday. Heavy snowbandswere located just west of New York City over portions of New Jersey, including the Franklin Lakes area.Exactly where these bands of heavy snowfall set up couldn't be determined until the storm was ongoing, which addedto the challenge for forecasters.

(MORE: )

The track of low pressure system helps to determine where snowbands will develop, andWinter Storm Quinn tracked just off the coast of New Jersey, with the center of the low-pressure system not that far from New York City. As a result, the heavier snowfall occurred west of Central Park.

Surface temperatures were another factor. Temperatureswest of New York City were 32 degrees or colder, while the temperature in Central Park remained in the 33- to 35-degree range for much of the storm.This relatively small temperature difference played an important role in the amount of snow that accumulated. While it can snow with temperatures above freezing, snow may melt when reaching the ground.

Generally speaking, temperatures closer to the coast tend to be warmer than areas farther inland due to the influence of the relatively mild waters of the Atlantic Ocean.