National Weather Service United States Department of Commerce



A rare and historic October Nor/easter delivered snow, heavy rain, and strong winds to the Mid Atlantic region on Saturday October 29, 2011. Low pressure organized off the Carolina coast late Friday night October 28th. This system strengthened as it tracked northeastward along the Eastern Seaboard Saturday morning October 29th. For many locations across New Jersey, eastern Pennsylvania, Delaware, and Maryland, the precipitation began as rain before daybreak. By mid-morning, however, many areas throughout eastern Pennsylvania and northern to central New Jersey had changed over to snow or a rain/snow mix as temperatures steadily dropped into the middle and lower 30s. Sleet was also reported across parts of the region, including into northern Delaware. Elsewhere, moderate to heavy rain continued throughout the day into central and southern Delaware and the eastern shore of Maryland.

Heavy, wet snow aided by strong winds resulted in tree and power line damage across northern New Jersey and northeast Pennsylvania by Saturday afternoon as the low pressure system churned northward along the Mid Atlantic coast. Gale force winds buffetted the New Jersey and Delaware coastlines. By mid to late evening, the last remaining bands of precipitation pushed through the region from southwest to northeast as the low pressure system exited the region.


A Winter Storm Watch was issued at 315 PM Thursday October 27 for the following areas: Sussex, Warren, and Morris in New Jersey; Carbon, Monroe, Berks, Lehigh, and Northampton in Pennsylvania. A Winter Storm Warning was issued at 352 PM Friday October 28 for the following areas: Sussex, Warren, Morris, Hunterdon, and Somerset in New Jersey; Carbon, Monroe, Berks, Lehigh, Northampton, Chester, Montgomery, and Bucks in Pennsylvania. Also at 352 PM Friday October 28, a Winter Weather Advisory was issued for the following areas: Middlesex, Western Monmouth, Mercer, Salem, Gloucester, Camden, and Northwestern Burlington in New Jersey; Delaware and Philadelphia and Pennsylvania; New Castle in Delaware; Cecil in Maryland. At 1258 PM Saturday October 29, a Winter Storm Warning was issued for the following areas: Middlesex and Mercer in New Jersey. At 1119 PM Saturday October 29, all Winter Storm Warnings and Winter Weather Advisories were cancelled.


A heavy, wet snow resulted in historic October snow accumulations throughout eastern Pennsylvania and northern to western New Jersey. A swath of 8 to 16 inches was measured across the Poconos, Lehigh Valley, and Berks county Pennsylvania and into the mountains of northwest New Jersey. The highest snowfall totals were recorded over the higher elevations of Carbon, Monroe, Lehigh, Bucks, Sussex, Warren, and Morris counties. North-central New Jersey also received significant snow accumulations from this rare October snowstorm, with 8 to 12 inches recorded over the higher terrain of Hunterdon and Somerset counties and 4 to 8 inches measured elsewhere across Mercer, Middlesex, Somerset, and Hunterdon counties. Meanwhile, the lower Delaware Valley experienced a rain/snow/sleet mixture throughout the course of this winter storm. Locations across Delaware, Philadelphia, Gloucester, Camden, and northwestern Burlington counties recorded 1 to 3 inches accumulation. Temperatures throughout the region were in the middle to lower 30s for most of this event, resulting in a heavy, wet snow that quickly accumulated on trees and power lines. The heavy snowfall combined with strong northerly to northeasterly winds, ranging from 15 to 25 mph and gusting up to 35 mph, resulted in downed trees and electric lines.

Along coastal locations of New Jersey and Delaware, gale force winds were measured and minor coastal flooding occurred. Tuckerton Shores in Ocean county New Jersey recorded a 54 mph wind gust, and Ocean city in Cape May county New Jersey measured a 51 mph gust. Strong winds were also felt into portions of Delaware, with a 49 mph gust recorded at Lewes and a 47 mph gust measured at Dover Airforce Base.

In locations where temperatures remained in the upper 30s to lower 40s, moderate to heavy rain fell throughout the day. From the eastern shore of Maryland into Delaware and southern New Jersey, rainfall totals ranged between 1 and 2 inches. For other locations in northern New Jersey and eastern Pennsylvania where rain changed over or mixed with snow, liquid equivalents from the storm also ranged from 1 to 2 inches of precipitation.

Significant Impacts/Aspects

This early season winter storm created substantial transportation delays and utility outages across eastern Pennsylvania and northern to central New Jersey. After mild conditions through much of October, many trees throughout the region still had their leaves. The wet snow and gusty winds from this storm system resulted in many trees and power lines bending and breaking under the weight of the heavy snow. Widespread power outages were reported throughout the Poconos, Lehigh Valley, and northern New Jersey, with hundreds of thousands of customers being without electricity during the storm. In addition to significant utility outages, downed trees and power lines resulted in numerous closings of local and secondary roads. Slippery road conditions also contributed to a few fatalities in traffic accidents across the region. A downed tree onto a house in Berks county Pennsylvania also resulted in a fatality. Finally, air transportation was also greatly impacted during the height of the storm, with dozens of flights being cancelled at the Philadelphia International Airport.


Information contained in this summary is preliminary. More complete and/or detailed information may be contained in subsequent monthly NOAA storm data publications.