Dire forecasts of record-setting storm surges, hurricane force winds and extreme coastal flooding along the northeast U.S. coast hastened mariners to head up rivers or tie down their vessels.
They had reason to be concerned.
As Hurricane Sandy ran parallel along the U.S. East Coast, the system continued to grow in size and its unusual turn toward the New Jersey coast would make this system historic.
Let’s review what happened to put Hurricane Sandy in the record books.
Hurricane Sandy started out as a tropical depression over the southwestern Caribbean on the morning of Oct. 22. The tropical depression remained stationary over warm waters and quickly strengthened into a tropical storm late that evening.
A large low pressure aloft over the northwestern Caribbean Sea and accompanying southerly winds in the upper levels of the atmosphere pushed Tropical Storm Sandy to the north-northeast toward Jamaica, but the slow movement allowed Sandy to rapidly intensify.
On the morning of Oct. 24, Tropical Storm Sandy became a hurricane prior to making landfall over southeastern Jamaica.
Hurricane Sandy then proceeded over eastern Jamaica and became a category 2 hurricane while making landfall over eastern Cuba during the overnight hours of Oct. 24. Hurricane Sandy weakened into a category 1 hurricane while passing over the central Bahamas overnight Thursday, Oct. 25.
A high situated over the Gulf of Maine allowed Hurricane Sandy to turn more northwestward, with the eye passing just east of Abaco Island on Friday morning, Oct. 26.
Although farther east along the northern Bahamas, tropical storm force winds extended as far west as the central Florida Keys. Heavy rain and coastal flooding impacted southeastern Florida on Oct. 25 through the morning of the 26th.
The high over the Gulf of Maine weakened and Hurricane Sandy turned back to the northeast during the early morning hours of Oct. 27. However, the central pressure of the tropical storm at the time was 969mb and tropical storm force winds extended as far west as eastern Georgia and South Carolina.
Hurricane Sandy continued to track several hundred miles offshore the southern Mid-Atlantic coast while the system’s central pressure dropped rapidly to 943mb by late morning of Oct. 29. Hurricane Sandy’s central pressure had surpassed the lowest pressure of a landfalling hurricane north of Cape Hatteras. The previous record was 946mb held by the “Long Island Express” Hurricane back in 1938.
The system was also the largest hurricane in the northwestern Atlantic Ocean, producing tropical storm force winds approximately 580 miles from the center of circulation.
What happened next was extremely unusual for a hurricane. Typically when a cold front moves over the eastern United States, it will deflect a hurricane away from the coast. A cold front was in place from central New York state southward to eastern North Carolina on Oct. 29.
However, an unusually strong high developed over the Labrador Sea, tucked between Canada and Greenland. This high pushed the large hurricane toward the northwest on the morning of Oct. 29 toward the Mid-Atlantic coast. The cold front was too weak to force the hurricane offshore and the cold front retrogressed back over the western Mid-Atlantic states.
The large area of easterly winds north of the hurricane combined with a full moon near high tide pushed a record setting storm surge into Long Island Sound and northern New Jersey by evening of Oct. 29. A storm surge of 13.88 feet was recorded in southern Manhattan, which produced the worst flooding in New York City since the 1850s.
The New Jersey coastline changed forever as Hurricane Sandy, which transitioned into a Nor’easter prior to landfall.
Hurricane Sandy’s initial track through the Caribbean and Bahamas was not at all unusual for late October. However the hurricane, which was twice the size of Texas, turned northwest over southern New Jersey. This was unprecedented.
Even as the system moved inland, blizzards developed in West Virginia and the high winds kicked up waves up to 25 feet on Lake Michigan.
Overall, 22 states were affected by Hurricane Sandy and certainly this system will not be forgotten for a long time to come.
Amanda Delaney is a senior meteorologist at Weather Routing Inc. (WRI). WRI has been providing forecasts and routing advice to mariners for more than 50 years. For more information, call +1 518-798-1110, e-mail firstname.lastname@example.org, or visit www.wriwx.com and www.seaweather.net.