Hurricane Sandy

Meteorological history and forecasts

Hurricane Sandy originated from a tropical wave in the western Caribbean Sea, becoming a tropical depression on October 22, 2012, south of Kingston, Jamaica. It was upgraded to Tropical Storm Sandy just six hours later, moving slowly northward towards the Greater Antilles due to a ridge to the north. The system intensified into a hurricane on October 24 as an eye began developing and it moved steadily northward ahead of an approaching trough. At about 1900 UTC that day, Sandy made its first landfall near Kingston, Jamaica, with winds of about 137 km/h. The storm then rapidly intensified over warm waters just offshore of Cuba, reaching its peak as a Category 3 hurricane with winds of 185 km/h and a minimum central pressure of 954 millibars before making a second landfall just west of Santiago de Cuba at 0525 UTC on October 25. After crossing Cuba, Sandy's structure became disorganized as it turned to the north-northwest over the Bahamas, and by October 27 it was no longer fully tropical as frontal structures developed in its outer circulation. A key factor in its eventual path was a blocking high-pressure system over Greenland, which caused the jet stream to kink and forced Sandy on an unusual northwestward track towards the United States, a movement often described as a 'left hook'. On October 29, Sandy made its final landfall near Brigantine, New Jersey, as a post-tropical cyclone with sustained winds of 130 km/h, before its remnants drifted over Ontario and merged with another low-pressure system on November 2.

The storm's path was correctly predicted nearly eight days in advance by the European Centre for Medium-Range Weather Forecasts (ECMWF), which forecast the unusual westward turn into the New York and New Jersey region. By October 27, the National Weather Service and National Hurricane Center confirmed this predicted path. The event prompted criticism of the National Weather Service for not employing its higher-resolution forecast models as effectively as its European counterpart, leading to a hardware and software upgrade completed at the end of 2013 to improve future prediction accuracy and range. Sandy's enormous size set records, with a gale-force wind diameter exceeding 1,850 kilometres, and its central pressure of 940 mbar resulted in the lowest barometric pressures ever recorded in many Northeastern U.S. cities. During its approach, Sandy briefly re-intensified to Category 2 intensity on the morning of October 29, around which time its convection began to diminish as it accelerated toward the New Jersey coast.

Impacts in the Caribbean

The Caribbean bore the initial brunt of Hurricane Sandy, with severe damage reported across several nations. In Jamaica, where the storm first made landfall as a hurricane, winds left 70 percent of residents without electricity, blew roofs off buildings, and caused one fatality, with total damage estimated at US$100 million. Acting Prime Minister Peter Phillips urged residents to take the storm seriously and care for neighbours, while officials shut down schools, government buildings, and the Kingston airport ahead of its arrival. Haiti suffered the greatest loss of life in the region, with Sandy's outer bands triggering flooding that killed 75 people, created food shortages, and left approximately 200,000 people homeless. The hurricane also caused two deaths in the neighbouring Dominican Republic, and in Puerto Rico, one man was swept away by a swollen river. In Cuba, the Category 3 landfall resulted in extensive coastal flooding and wind damage inland, destroying about 15,000 homes, killing 11 people, and inflicting an estimated US$2 billion in damage. The Bahamas experienced two fatalities and an estimated US$700 million in damage as the storm passed through the archipelago. Even Bermuda, far to the north, was placed under a tropical storm watch on October 26 due to the storm's massive size and anticipated wide-reaching impacts.

Preparations across the islands were extensive and began as soon as Sandy became a tropical cyclone. The Jamaican government issued a tropical storm watch for the entire island on October 22, upgrading it to a warning and a hurricane watch early on October 23, and then a full hurricane warning by 1500 UTC that day. The Haitian government issued a tropical storm watch shortly after Jamaica's first alert, modifying it to a warning by late October 23. Cuban authorities posted a hurricane watch for six eastern provinces at 1500 UTC on October 23, switching it to a hurricane warning only three hours later. The Bahamian government issued a series of tropical storm watches and warnings for numerous islands beginning on October 23, including the Acklins, Cat Island, and Exuma, with some upgraded to warnings by the next day. These actions, while mitigating some potential losses, could not prevent the widespread destruction caused by the intense winds and prolific rainfall associated with the hurricane.

Impact on the United States

Hurricane Sandy affected 24 states across the eastern United States, from Florida to Maine and west to Michigan and Wisconsin, with the most severe damage concentrated in New Jersey and New York. The storm's surge hit New York City on October 29, flooding streets, tunnels, and subway lines and cutting power to large sections of the city and surrounding region. Overall damage in the United States was catastrophic, amounting to US$65 billion. The storm's hybrid nature led forecasters like Jim Cisco of the Hydrometeorological Prediction Center to coin the term 'Frankenstorm', though many media outlets later used 'superstorm'. Utilities along the East Coast prepared for massive power outages, with researchers from Johns Hopkins University using a computer model to conservatively forecast that 10 million customers could lose electricity. The Federal Emergency Management Agency (FEMA) monitored the storm through regional offices and coordinated closely with state and tribal partners, and President Barack Obama signed emergency declarations for several states on October 28, allowing them to request federal aid.

Extensive preparations were undertaken across multiple states. Over 5,000 commercial airline flights scheduled for October 28 and 29 were canceled, and Amtrak canceled some services through October 29. The U.S. Navy sent more than twenty-seven ships and forces to sea from Naval Station Norfolk for their protection. States of emergency were declared from the Carolinas to New England. In North Carolina, Governor Beverly Perdue declared a state of emergency for 38 eastern counties on October 26, later extended to 24 western counties where up to 30 centimetres of snow was anticipated. The National Park Service closed at least five sections of the Blue Ridge Parkway. In Virginia, Governor Bob McDonnell activated 630 National Guard personnel, and both presidential candidate Mitt Romney and Vice President Joe Biden canceled campaign appearances. In Washington, D.C., Mayor Vincent Gray declared a state of emergency, federal offices closed, and all Metro rail and bus service was canceled on October 29. Maryland Governor Martin O'Malley also declared a state of emergency, ordering evacuations in parts of Ocean City and other counties, while officials warned of potential environmental threats from sediment behind the Conowingo Dam.

The storm's disruption was widespread and detailed. In Maryland, the Maryland Transit Administration canceled all bus, light rail, Amtrak, and MARC train service for October 29 and 30, and six shelters opened in Baltimore. Maryland Insurance Commissioner Therese M. Goldsmith activated an emergency regulation requiring pharmacies to refill prescriptions regardless of their last refill date. The Chesapeake Bay Bridge and the Millard E. Tydings Memorial Bridge were closed. In Florida, schools on the Treasure Coast closed on October 26. The National Guard and U.S. Air Force put as many as 45,000 personnel in at least seven states on alert for possible duty. These measures show the scale of the anticipated crisis and the extensive mobilization required to confront it.

Impact and response in Canada

While the core of Hurricane Sandy struck the United States, its immense circulation brought significant effects to Eastern Canada, particularly Ontario and Quebec. The storm caused two fatalities in Ontario as its remnants moved through the region in the days following U.S. landfall. The financial impact was substantial, with total damage across the two provinces estimated at C$100 million. The effects included high winds, heavy rainfall, and power outages affecting many communities. The storm's post-tropical phase continued to generate hazardous conditions as it drifted northward and then northeastward over Ontario, before merging with another low pressure area over Eastern Canada on November 2. The Canadian response involved local and provincial emergency management teams addressing downed trees, flooding, and infrastructure damage. The event demonstrated the far-reaching nature of major hurricane systems and their ability to cause disruption well inland and across international borders, serving as a case study for cross-border emergency management coordination.

Relation to climate change and sea level rise

The unusual characteristics and severe impacts of Hurricane Sandy fuelled scientific discussion about its possible connections to anthropogenic climate change. Climate scientist Kevin E. Trenberth noted that while the storm was caused by natural variability, all weather events now occur in an environment made warmer and moister by global warming, which can enhance their intensity. One contributing factor was abnormally warm sea surface temperatures off the U.S. East Coast, more than 3°C above normal, to which global warming had contributed approximately 0.6°C. This warmer atmosphere holds more moisture, potentially leading to stronger storms and higher rainfall totals. The unusual blocking pattern over Greenland that steered Sandy westward has been studied in the context of Arctic ice melt altering jet stream patterns, as suggested by Mark Fischetti of Scientific American, though Trenberth noted the null hypothesis remained that this was natural weather variability.

A critical factor in the storm's destructiveness was higher sea levels. Sea level in the New York and New Jersey region has risen by nearly 30 centimetres over the past century. Scientific analysis estimated that human-driven climate change was responsible for approximately 8.9 centimetres of that rise. This additional height allowed Sandy's storm surge to cause approximately US$8.1 billion of the reported economic damage and extended the flood zone to impact about 71,000 more people than would have been affected otherwise. Harvard geologist Daniel P. Schrag described Sandy's 4-metre storm surge as a precursor to what may become the 'new norm' for the Eastern seaboard by mid-century. This highlights the long-term infrastructural and planning challenges posed by rising seas, where storm surges ride on a higher baseline ocean level, increasing the reach and power of coastal flooding during extreme events.

Key statistics and records

Hurricane Sandy set several meteorological and impact records due to its unique size and strength. It was the largest Atlantic hurricane ever recorded by diameter, with tropical-storm-force winds extending 1,850 kilometres from the centre. Its central barometric pressure dropped to 940 millibars, setting records for the lowest pressures ever observed in many cities across the Northeastern United States. In terms of seasonal activity, Sandy was the eighteenth named storm, the tenth hurricane, and the second major hurricane of the 2012 Atlantic hurricane season. The storm's financial toll was immense, with total damage approaching US$70 billion, making it one of the costliest tropical cyclones on record at the time. The human cost was also severe, with 254 fatalities across eight countries from the Caribbean to Canada.

The storm's impacts were felt across a remarkably wide area and included specific, costly events. It was the largest Atlantic hurricane by wind field diameter, measuring 1,850 km. It caused record low barometric pressures across the U.S. Northeast and was the second costliest U.S. hurricane at the time with US$65 billion in domestic damage. The storm caused 254 total fatalities in eight countries, with Caribbean damage including US$2 billion in Cuba and US$700 million in the Bahamas. In Canada, it caused C$100 million in damage in Ontario and Quebec, and it affected 24 U.S. states from Florida to Wisconsin. Its path was correctly forecast by the European model eight days in advance, a notable achievement in meteorological prediction. These figures show the historic scale of the disaster and its significance for meteorology, emergency management, and climate science. The storm's specific damage totals, like the US$100 million in Jamaica and the 15,000 homes destroyed in Cuba, provide concrete examples of its destructive power across different regions.

Questions about Hurricane Sandy

How much damage did Hurricane Sandy cause in Canada?

Hurricane Sandy caused significant damage in Eastern Canada, with a total estimated cost of C$100 million across Ontario and Quebec. The storm's remnants brought high winds and heavy rain to the region after it made landfall in the United States. This damage included downed trees, power outages, and property damage. The storm also resulted in two fatalities in Ontario.

How did climate change influence Hurricane Sandy?

While Hurricane Sandy was a natural weather event, scientists agree climate change likely exacerbated its impacts. Warmer sea surface temperatures, partly attributable to global warming, provided more energy for the storm. Higher atmospheric moisture content can increase rainfall potential. Most significantly, anthropogenic sea level rise, estimated at 8.9 centimetres for New York, allowed the storm surge to be higher and more destructive, causing billions in additional damage and flooding more homes.

What was the death toll from Hurricane Sandy?

Hurricane Sandy caused 254 fatalities across eight countries. The Caribbean suffered heavily, with 75 deaths in Haiti, 11 in Cuba, two in the Dominican Republic, and one each in Jamaica and Puerto Rico. The United States experienced numerous fatalities. In Canada, the storm caused two deaths in Ontario. The wide geographic spread of fatalities highlights the storm's immense scale and power.

How was New York City affected by Hurricane Sandy?

New York City was severely impacted when Sandy's storm surge hit on October 29, 2012. The surge flooded streets, subway tunnels, and underground infrastructure, leading to massive power outages in and around the city. The flooding caused billions of dollars in damage to homes, businesses, and critical systems. The event exposed the vulnerability of coastal cities to such storms and prompted major reviews of flood protection and infrastructure resilience.

Why was Hurricane Sandy called a 'superstorm'?

Hurricane Sandy was unofficially referred to as a 'superstorm' due to its extremely large size and devastating hybrid nature. It was the largest Atlantic hurricane on record by diameter, with tropical storm force winds spanning 1,150 miles. As it approached the United States, it merged with a winter storm front, creating an unusual post tropical cyclone with both tropical and extratropical characteristics. This massive storm caused nearly $70 billion in damage across the Caribbean and the United States. The media and forecasters used the term 'superstorm' to describe this unprecedented and complex weather system.

What made Hurricane Sandy's path so unusual?

Hurricane Sandy's path was unusual because it took a sharp westward turn into the New Jersey coast, described as a 'left turn' or 'left hook', rather than moving eastward out to sea. This atypical northwest path was caused by a ridge of high pressure over Greenland that created a kink in the jet stream. Most Atlantic hurricanes in that position are forced east by the Prevailing Westerlies. The European Centre for Medium Range Weather Forecasts correctly predicted this unusual path nearly eight days before landfall. Sandy ultimately made landfall near Brigantine, New Jersey, on October 29 as a post tropical cyclone with hurricane force winds.

Sources and further reading

• Hurricane Sandy (Wikipedia)
• Hurricane Sandy (weather.gov)
• Hurricane Sandy facts and information (nationalgeographic.com)
• Case Study, Hurricane Sandy (metlink.org)

Checked by the Your Space Hamilton desk. Last updated 2026-10-18.