Thunderstorm Wind — Cumberland, New Jersey

2012-06-29 to 2012-06-30 · near Greenwich, Cumberland, New Jersey

Event narrative

A gust front outrunning a cluster of severe thunderstorms entered near Greenwich in western Cumberland County at approximately 12:23 am EDT on the 30th. This gust front produced damaging wind gusts ranging from 65 to 70 mph as it traversed eastward across the county. Within approximately 10 to 20 minutes of the gust front passage, a potent line of severe thunderstorms tracked eastward into Cumberland County. One thunderstorm cell in particular experienced rapid intensification and expansion as it tracked through southern New Jersey. Destructive wind gusts, estimated as high as 75 mph, resulted in significant tree and power line damage county-wide. Eight homes in the county were destroyed, forty others suffered major damage. In addition, one hundred thirty one other homes suffered minor damage and fifty others were affected.

Several wind gusts in association with the gust front passage or cluster of intense thunderstorms were measured across the county by trained spotters, mesonet sites, and ASOS equipment. A 59 mph wind gust associated with the gust front was measured in Newport by a trained spotter at 12:40 am EDT on the 30th. Soon after, severe thunderstorms tracked through the Newport area, producing winds measured at 59 mph by a trained spotter. The strong winds associated with the cluster of thunderstorms occurred at 12:50 am EDT on the 30th and lasted for a duration of 10 minutes.

Intense thunderstorms produced several other measured wind gusts as they progressed from west to east across the county. A 62 mph gust was measured by a mesonet station in Upper Deerfield Township at 12:45 am EDT. Two locations recorded the highest measured gust of 67 mph in Cumberland County. A mesonet station in Bivalve measured a 67 mph gust at 12:50 am EDT, and the ASOS equipment at the Millville Municipal Airport (KMIV) measured a 67 mph gust at 12:57 am EDT. In addition, the KMIV Airport ASOS also measured a 63 mph gust at 12:52 am EDT. The final measured gust in Cumberland County of 64 mph was recorded in Vineland by a trained spotter at 1:00am EDT on the 30th. Severe thunderstorms exited eastern Cumberland County, including the town of Port Elizabeth, at approximately 1:19 am EDT on the 30th.

Widespread damage occurred across Cumberland County as a result of the strong wind gusts associated with the gust front and cluster of severe thunderstorms. Numerous trees were knocked down in Vineland and Bridgeton, and damage to some buildings was also reported in Vineland. Trees were reported down along Glade Road in Maurice River Township. Electric wires were knocked down in Delmont, and multiple large tree limbs blew down in Port Norris.

Thousands of customers lost power across the county as a result of the extensive tree and wire damage, with many areas experiencing power outages for about one week. According to Vineland Electric, about 1,800 customers did not have their power restored until the week of July 9th. As a result, the city of Vineland, as well as other surrounding communities, provided air-conditioned cooling centers as temperatures soared into the 90s during the week following the derecho. Vineland also postponed its Independence Day fireworks twice.

Wider weather episode

A well-organized cluster of thunderstorms with a history of producing widespread damaging winds advanced into a hot, unstable airmass over the Mid Atlantic. This derecho produced widespread, significant wind damage from southern New Jersey southward into the Delmarva during the late evening and overnight of the 29th. Salem, Cumberland and Atlantic Counties were hit the hardest. The counties were battered by the derecho which downed trees, power lines and poles, sparked fires and destroyed some homes.

There were three storm related deaths, two boys camping in Salem County and a man whose boat capsized in Absecon Bay in Atlantic County. A preliminary damage assessment put the cost at around $20 million for the three counties. In all sixteen homes were destroyed, ninety-two suffered major damage, one hundred eighty-seven suffered minor damage and another one hundred and twelve were affected by the derecho. In addition, forty-one businesses suffered major damage and three hundred twenty-nine suffered minor damage. A state of emergency was declared in Atlantic County. Governor Chris Christie mobilized the National Guard to help provide fuel and water. President Barack Obama has issued a disaster declaration for parts of South Jersey in the wake of the derecho. The president ordered federal aid to supplement state and local recovery efforts in Atlantic, Cumberland and Salem counties. Federal funds will be available to state and local governments and certain nonprofit private organizations. Atlantic City Electric reported 206,000 of its customers lost power; 105,000 of the homes and businesses were in Atlantic County. On Sunday July 1st, 119,000 of its customers were still without power. The utility restored power to its last customers on July 11th. Meanwhile in Cumberland County, Vineland Electric expected its remaining 1,800 customers that lost power to have it restored during the week of July 9th.

Strong thunderstorm development began across the Midwest and Lower Great Lakes regions during the afternoon of the 29th, with storms initiating across northern Illinois, near Chicago. Strong mid-level winds and an unstable airmass contributed to rapid development as well-organized storms progressed from northern Illinois through Indiana and Ohio. This robust convection continued to track southeastward into an airmass that was even more unstable due to abundant daytime surface heating. Late afternoon temperatures had peaked mainly in the mid to upper 90s with high humidity throughout the Mid Atlantic states, and as the potent thunderstorm cluster progressed from the Great Lakes to the central Appalachians and into the Mid Atlantic by late evening, thunderstorm activity was reinvigorated.

A robust gust front outpaced the main thunderstorm line, producing strong wind gusts as it traveled from the eastern shore of Maryland into Delaware and southern New Jersey. Shortly thereafter, the potent thunderstorm line tracked through the region, with additional damaging wind gusts. One cell in particular around Baltimore, MD experienced rapid intensification and expansion as it raced eastward into northern Delaware and southern New Jersey. This massive cell produced extreme damage throughout Salem, Cumberland, and Atlantic Counties in New Jersey. Damage to trees, power lines, and buildings was also significant throughout Delaware and the eastern shore of Maryland. Thunderstorms also dropped hail in several locations, ranging from penny to golf-ball size. Destructive wind gusts, between 65 mph to nearly 90 mph, were measured as this derecho tracked from the Lower Great Lakes to the Mid Atlantic coast.

View location on OpenStreetMap → (39.4000, -75.3300)

Source: NOAA Storm Events Database, event_id 393665. Narrative written by the NWS forecast office that issued the report.