High Wind — Southern Lycoming, Pennsylvania

2012-10-29 to 2012-10-30 · Southern Lycoming, Pennsylvania

Event narrative

High winds knocked down several trees and utility wires, closing dozens of roads throughout the county. Sporadic power outages were also reported county-wide.

Wider weather episode

Hurricane Sandy began as a tropical wave over the Caribbean Sea around 19 October 2012 and became a powerful storm by 23 October 2012 before making its long track over the western Atlantic, just off the East Coast of the United States and then into New Jersey and Pennsylvania. High latitude blocking over the North Atlantic and the interaction with a strong upper-air disturbance over the central Appalachians allowed Sandy to take a sharp left turn and accelerate northwest from the western Atlantic into southern New Jersey and across southern Pennsylvania. The center of post-tropical Sandy moved westward across the state beginning late in the evening on the 29th. The remnants of Sandy, a weakening low pressure system, exited northwestern Pennsylvania into Canada on October 31, 2012.

The highest recorded storm-total rainfall amount obtained in PA for the Oct 28-31, 2012 period was 7.94 inches at Schellsburg 2.6 WNW in Bedford County. There was an unconfirmed report of 8.15 inches at Hanover 5.4 S in York County which has not been verified. There was widespread storm-total rainfall amounts of 3 to 5 inches over the central and south portions of the Commonwealth with locally up to near 8 inches along the MD border region. However despite the heavy rainfall, hydrologic impacts were rather limited. Most of the significant flooding occurred in the southern most counties bordering Maryland, where the heaviest rainfall totals occurred. Areal Flood Warnings and Advisories were issued for the region. Six river forecast points rose above flood stage, with all but the Conestoga River at Lancaster (with moderate flooding) experiencing minor flood crests.

The impacts from the strong winds were widespread, with peak wind gusts were measured in the 50 to 60 mph range. High wind watches and warnings were issued well in advance of the storm. There were several reports of roof and other minor structural damage to homes and businesses. Widespread reports of trees down and power lines down were received. Wind damage caused significant power outages at the height of the storm.

Cold air was drawn into the southwest-side of the storm and produced heavy snows from October 29-31 across the southern Laurel Mountains. Amounts in excess of a foot were reported at several locations over the highest elevations including 14 inches at Laurel Summit in Somerset County. The ridges in Cambria County received between 2 and 4 inches.

There was one indirect storm-related fatality that occurred on the evening of the 29th. A person was killed in a Somerset County traffic accident, when their car slid off snow and slush covered road into a farm pond.

A disaster emergency was issued by the Governor on October 26, 2012. This was followed by a Presidential Emergency Declaration on October 29, 2012.

In summary, Superstorm Sandy was an enduring late season tropical cyclone which developed during a period of high-latitude blocking over the Atlantic Basin. The storm came ashore in New Jersey with significant impact to the coastal regions of the Mid-Atlantic states. The interaction of hurricane Sandy with a strong upper-air disturbance produced one of the more memorable and destructive storms in the Mid-Atlantic region in over 100 years.

Source: NOAA Storm Events Database, event_id 413147. Narrative written by the NWS forecast office that issued the report.