High Wind — Philadelphia, Pennsylvania

2012-10-29 · Philadelphia, Pennsylvania

Wider weather episode

Post Tropical Storm Sandy caused an initial estimate of $20 million dollars in damage in Pennsylvania and directly or indirectly caused 15 deaths across the state. Most of the damage in the eastern part of the state was wind related as wind gusts reached as high as 81 mph. Some moderate creek flooding occurred in the southeast part of the state and record tidal flooding occurred along the tidal Delaware River. Hundreds of roads were closed because of downed trees and major transportation in and out of the region was halted for two days and only slowly returned starting on the 31st. PECO Energy which serves customers in southeastern Pennsylvania, broke their all-time outage record of 850,000 customers without power. At any one time, the greatest number of statewide outages was approximately 1.2 million utility customers on the 30th. In the Mount Holly warning and forecast area of Eastern Pennsylvania, Sandy was responsible for eleven deaths, one that was considered directly caused by the system: a Berks County man was killed by a falling tree. Hardest hit with wind damage were Lehigh and Montgomery Counties. Chester and Delaware Counties were most affected by creek flooding.

Governor Tom Corbett declared a state of disaster emergency for Pennsylvania as did Mayor Michael Nutter of Philadelphia. President Barack Obama also declared a disaster emergency. Thirty-three counties in the state issued emergency declarations. Most schools and businesses were closed on the 29th and 30th. The American Red Cross opened 48 shelters in the state that could accommodate 31,000 people. In addition two super shelters were opened in West Chester and East Stroudsburg to assist evacuees from New Jersey. About half of the drinking and wastewater facilities lost power in the state. In all, about twenty-five sewage treatment plants were either bypassing or only on partial operations. Sixty-two water treatment facilities were affected and fifty-eight boil water advisories were issued.

In anticipation of Sandy's arrival, SEPTA shut down all commuter service in and around Philadelphia at 1230 a.m. EDT on the 29th. AMTRAK service along the northeast corridor was also shut down at 700 p.m. EDT on the 29th. All flights in and out of Philadelphia International Airport were cancelled on the 29th. In and around Philadelphia, the Ben Franklin, Betsy Ross, Walt Whitman, and Commodore Barry bridges were closed the evening on the 29th. They were re-opened on the 30th. Most of the major interstates leading into and around Philadelphia were also closed that evening: Interstates 95, 76, 476 and 676 as well as United States Route 1. Limited SEPTA resumed service at 12 p.m. EDT on the 30th. AMTRAK service along the northeast corridor was expected to resume on the 31st. Philadelphia International Airport has resumed limited flights on the afternoon of the 30th. There were 425 roadways that were closed statewide due to the combination of downed trees, downed utilities and flooding. There were 21 precautionary bridge closures awaiting inspection. The number of closed roadways dropped to 245 on November 1st, 141 on November 3rd, and 38 (mainly because of downed utilities) on November 5th. Trash and recycling schedules were delayed. Area hotels were booked solid as people without heat or that had home damage seeked shelter. There were also long gas lines because of problems with gas supplies in New York and New Jersey. Motorists were given two week extensions for their vehicle registrations and inspections that were due by the end of October.

PECO Energy reported a record breaking 850,000 of its customers lost power. Pennsylvania Power and Light reported 370,000 of its customers lost power and Metropolitan Edison reported 246,000 of its customers. Statewide about 520,000 utility customers were still without power on November 1st. Power was fully restored to Pennsylvania Power and Light customers on November 4th, Metropolitan Edison the week of November 4th and PECO Energy on November 6th. Power outages forced Carbon and Monroe Counties 911 operations to default to back-up and emergency powers. The high winds damaged four communication sites in Berks County. They were operating on reduced functionality but still maintained coverage throughout the county.

In Berks County, a tree fell onto the porch of a home in Pike Township, and killed a 62 year-old man. Other deaths attributed to Sandy included: in Montgomery County, a 90-year-old female was found deceased in her apartment after being overcome by fumes from her generator in the garage below her living room, in Carbon County, a 66-year-old male died at hospital due to carbon monoxide poisoning from generator running in the garage, in Northampton County, a 17- year-old boy drove his ATV into a downed tree, a 67-year-old male in Lehigh Township was found on the evening of November 2nd, apparently ran over by his tractor while cleaning up from the storm, in Lehigh County an 86-year-old female from Orefield was found unresponsive in her yard and pronounced dead from hypothermia, another man in Lehigh County also died from exposure, a 48-year-old female was found deceased in her home in Lower Macungie Township after being overcome by fumes from generator in her garage, in Berks County, an 86-year-old man died from carbon monoxide poisoning and in Philadelphia a 95-year-old female died from an electrical malfunction shortly after power was restored and a 64-year-old female died from a fire. There were six direct or indirect reported injuries. An infant in Upper Darby (Delaware County) was injured when a tree fell through the house. In Levittiown (Bucks County), two children were also injured when a tree fell through their home. Two people in Monroe County were hospitalized due to carbon monoxide poisoning and a firefighter was injured in Carbon County responding to the carbon monoxide fatality.

Tropical Storm Sandy formed in the Caribbean Sea on the 22nd of October. After drifting slowly southwest into the 23rd, Sandy turned to the north and intensified to a hurricane on the 24th just before making landfall in Jamaica during that afternoon. Hurricane Sandy continued to the north and intensified to a strong category two hurricane before making landfall again in Cuba shortly after Midnight EDT on the 25th. Hurricane Sandy emerged on the other side of Cuba during the morning of the 25th and proceeded to drift northwest as a category one or two hurricane as it moved through the Bahamas on the 25th and 26th. Overnight on the 26th, Hurricane Sandy (Category 1) started to move toward the north-northeast, a motion that continued into the evening of the 28th. From there, Sandy's motion became driven by two factors. An anomalously strong blocking ridge over the Canadian Maritimes prevented Sandy from escaping to the east. Simultaneously, an approaching and deepening extratropical trough was about to capture Sandy. The combination of the two, turned Sandy to the north overnight on the 28th and then to the northwest on the 29th. Hurricane Sandy received one last jolt of tropical energy as it passed across the Gulf Stream during the morning of the 29th. The lowest recorded central pressure of 940 millibars (27.76 inches) occurred when Category 1 Hurricane Sandy was about 110 miles southeast of Atlantic City at 2 p.m. EDT on the 29th. As Sandy continued to move northwest and interact with the mid latitude trough, its interaction continued to make it less tropical, but did not weaken it much. Sandy continued to make a harder turn to the left (west) and made landfall in Atlantic County as a post tropical storm in Brigantine City just north of Atlantic City at 730 p.m. EDT on the 29th. The estimated minimum central pressure was 945 millibars. The lowest recorded central pressure was 945.6 millibars at the Atlantic City Marina at 734 p.m. EDT. From there, Sandy continued to weaken or fill as it moved west. At 9 p.m. EDT, the low pressure system was in western Atlantic County and continued to move west-northwest. Sandy entered Pennsylvania in Delaware County around 1030 p.m. EDT. At 11 p.m. EDT, the post tropical storm (about 954 millibars) was located in southern Chester County. Post tropical storm Sandy continued to move west-northwest and weaken. At 2 a.m. EDT on the 30th, the 962 millibar low was located near Harrisburg, Pennsylvania and at 8 a.m. EDT the 979 millibar low was near Altoona, Pennsylvania. From there, the rapidly weakening low pressure system moved northwest and reached Lake Erie (993 millibars) at 8 p.m. EDT that evening and from there drifted north into Canada.

The unique aspect of Sandy and unlike most tropical systems was the multi-tide cycle increase of onshore winds prior to landfall. In Upper Delaware Bay and tidal sections of the Delaware River, some minor tidal flooding occurred during the evening high tide cycle on the 28th, moderate (upper Delaware Bay) and major (the tidal Delaware River) record breaking tidal flooding occurred during the one overnight high tide cycle on the 29th as Sandy moved westward. The storm surge averaged 4 to 5 feet. The region was spared higher surges as Sandy made landfall in New Jersey and the winds prior to landfall pushed water down the Delaware River and Delaware Bay. Borderline minor to moderate tidal flooding occurred during the subsequent daytime high tide cycle on the 30th. Minor tidal flooding occurred along tidal sections of the Delaware with the high tide cycle on the 31st. Tidal sections of the Delaware River were spared significant runoff from the non-tidal sections of the river as the heaviest rain occurred in the southern half of New Jersey.

Strong north to northeast winds associated with Sandy started to spread across the state during the morning of the 29th. High or damaging winds started during the middle of the afternoon on the 29th in the local Philadelphia area. High winds spread across the rest of Eastern Pennsylvania by the start of the evening. Most of the peak wind gusts (between 60 mph and 80 mph) occurred during the middle evening hours of the 29th as Sandy was making landfall. The high winds were over by around Midnight EDT that night and as Sandy rapidly weakened. Except for the Poconos where it lingered until the morning, most of the strong wind gusts were also over shortly after Midnight EDT on the 30th. The highest measured wind gust in Mount Holly's forecast and warning area in Pennsylvania was 81 mph in Allentown (Lehigh County).

Heavy rain also occurred with Sandy in the southeast part of the state. This made it easier for shallow rooted and leafed trees to be uprooted, it also complicated the tidal flooding. Unlike some of the more recent tropical systems to affect the area, the heaviest rain fell south of the state of Pennsylvania. Event rainfall totals averaged 1 to 2.5 inches in the Poconos, Lehigh Valley and Bucks County, 2.5 inches to 5 inches in Berks, Montgomery, Delaware and Philadelphia Counties and 4 to 6 inches in Chester County. The steady rain associated with Sandy started to spread into the state during the day on the 28th and slowly edged north and northeast and reached all of the state by the morning of the 29th. The heaviest rain fell during the morning and afternoon on the 29th. The rain ended during the middle of the day on the 30th.

In the city of Philadelphia, about 10,000 people were evacuated including the Eastwick Neighborhood. Approximately 100 trees were knocked down and about 140,000 PECO customers lost power. Hundreds of events were cancelled or postponed. Tidal flooding occurred along Delaware Avenue. The refineries within the city could not operate at full capacity because of power outages. Bucks County was one of the hardest hit counties in Eastern Pennsylvania with around 200,000 homes and businesses losing power. Thirty-eight roadways were closed due to wind damage with the most closures in Solebury Township. In Montgomery County, around 200,000 homes and businesses also lost power. The high winds destroyed one home in the county, caused major damage to sixteen others, minor damage to nineteen others and affected an additional twenty homes. The most road closures were in Upper Dublin Township while the hardest hit townships were East Norriton, West Norriton, Lower Providence, Upper Merion, Lower Merion and Whitpain. In Delaware County, a home in Newtown Square was badly damaged by a downed tree. About 86,000 homes and businesses lost power. In Chester County, three homes were damaged by downed trees in West Goshen Township. About 74,000 homes and businesses lost power. Six roadways in the township were closed. Most of the worst wind damage occurred in the eastern part of the county in East Goshen, East Whiteland, Tredyffrin, Westtown and Easttown Townships. County offices and Longwood Gardens reopened on the 31st.

In Berks County, thirty-one roadways were closed. In the Lehigh Valley, 181,000 homes and businesses lost power. In Lehigh County, the high winds caused major damage to thirteen homes, minor damage to thirty-two homes and affected an additional eighty-six homes. Flights were cancelled from Lehigh Valley International Airport on the 29th and through Noon EDT on the 30th. About 29 roads were closed. In neighboring Northampton County, thirty-two roadways were closed. In the Poconos, in Monroe County, the worst reported wind damage occurred in Lehman and Middle Smithfield Townships. The Delaware Water Gap National Recreation Area was closed. At the Pocono Raceway, the wind knocked down a steeple. Thirty-one roadways were closed. Carbon County fared better as only five roadways were closed.

Peak wind gusts included 81 mph in Allentown (Lehigh County), 77 mph in Forks Township (Northampton County), 76 mph in Bensalem (Bucks County), 70 mph at the Lehigh Valley International Airport, Northeast Philadelphia Airport and Bushkill (Northampton County), 68 mph in Perkasie (Bucks County) and the Philadelphia International Airport, 66 mph in Mount Pocono (Monroe County), 64 mph in Mount Aetna (Berks County), 62 mph in Wind Gap (Northampton County), 59 mph in Newbold (Bucks County), Pottstown (Montgomery County) and Newtown Square (Delaware County), 56 mph in Yardley, 48 mph in West Grove (Chester County), 46 mph in Reading (Berks County) and 45 mph in Coatesville (Chester County).

In Philadelphia, the overnight high tide on the 29th reached a record breaking 10.62 feet above mean lower low water. The previous record was 10.5 feet above mean lower low water during a pair of nor'easters: April 17, 2011 and November 25, 1950. Flooding was reported in Philadelphia along the Delaware River on Delaware Avenue and Columbus Boulevard. In Bucks County, at Newbold Island the highest crest was 12.27 feet above mean lower low water.

Source: NOAA Storm Events Database, event_id 416855. Narrative written by the NWS forecast office that issued the report.