Memories of ‘Snowtober’ and Superstorm Sandy in 2011 and 2012
Something felt different as Halloween of 2011 approached, and everyone could tell by looking up. On Saturday, Oct. 29, 2011, snowflakes began to flurry throughout the Pottstown area.
Fast-forward one year later — same time of year, same place, even the same date. Something was different again. In the Pottstown region, on Oct. 29, 2012, residents sheltered in their homes as a superstorm made landfall in New Jersey.
This turnaround was not a scary Halloween joke. The two-year succession of storms was a reality that made many people reconsider their perception of fall weather. In the end, though, it became apparent that these events were always in the realm of possibility.
This is the story of 2011’s “Snowtober” and 2012’s Superstorm Sandy.
Residents across the northeast shivered as they walked outside on a late October morning of 2011. A cold air mass had caused temperatures to be over 15 degrees below average, which meant highs in the 40s around Pottstown.
Along with this, a storm system was forming off the Southeast coast. It would travel northward in the coming days, riding the seaboard to the Northeast.
This, forecasters noticed, was the classic setup for a Nor’easter.
Nor’easters rotate counterclockwise over the Atlantic Ocean directly off the eastern coastline. This blows wind onto land from the northeast, hence the storm’s name. They are strongest between September and April because cold northern air clashes with warmer ocean temperatures, providing fuel for the storm.
2011 was unique, however, because of the extremely unseasonable temperatures. In addition, such a storm would pull the core of cold air deeper into the region, dropping temperatures into the twenties for some locations. This combination only meant one thing.
Meteorologists gawked as their computer models displayed outputs for snowfall totals from Philadelphia to Boston.
As the sun rose on Saturday, Oct. 29, a cold rain overtook the Pottstown region. Yet by 10 a.m., the temperature had dropped from 40°F to 33°F, and fat snowflakes were deposited from the sky.
This temperature, while cold, created heavy and wet snow instead of the powdery snow commonly seen on colder days. For context: dry, fluffy snow places 6,000 pounds of pressure on a roof, while wet, heavy snow exerts a whopping 19,000 pounds.
In 2011, this snow led power lines to topple and knocked out power to 3 million across the Northeast. Also, trees still with a full set of orange leaves fell across streets, cars, and homes. In Central Park alone, an estimated 1,000 trees were lost.
The snow canceled school, postponed college application deadlines, and even moved a holiday. Multiple communities from Pennsylvania to Maine shifted the celebration of Halloween to the first days of November.
Around Pottstown, about 6 inches of snow fell, breaking the record by far for any October snowstorm. Records were easily broken across other cities as well. For example, Hazelton recorded a whopping 16inches. Concord, New Hampshire, received 22.5 inches of snow in 16 hours, the second greatest 24-hour snowfall amount in the town’s entire history.
With all set and done, a photo was taken from space on the day before Halloween, 2011, showing 86% of the Northeast covered in snow with an average depth of 4 inches. Expectations of the standard Halloween weather were shattered that year as children’s shoes crunched on snow instead of leaves while trick-or-treating.
Jump one year into the future, with people hoping that Halloween would be different. It was very different, but in the worst way possible — a Sandy way.
Tropical Storm Sandy was named on October 24th, 2012, in the middle of the southwestern Caribbean sea, a few hundred miles south of Cuba. It moved northward from there, gradually strengthening over the warm Caribbean waters.
On the morning of Oct. 25, Sandy made landfall in Cuba as a major Category 3 Hurricane, with sustained winds of 125 mph. It caused major damage to
the country. This was the strongest that the storm ever would be, but the extent of its devastating effects was far from over.
Sandy continued northward from Cuba through the Bahamas as a hurricane, causing wind and rain damage on the islands. It also produced significant beach erosion and flooding in Florida, undermining two homes.
Forecast models then focused on where Sandy was heading, and as the days progressed, confidence grew that a rare solution would come to fruition. Sandy would make a 90-degree left turn straight into the Northeast.
This was improbable in many regards. Such a track was only possible because of a strong atmospheric ridge set up over Greenland. This basically creates a blockage where winds go against the standard west to east gradient, thus changing a storm’s course.
A good analogy is to think of the blockage and any incoming storms as opposing magnets. The “storm magnet” is repelled by the “blocking magnet,” and it must choose which direction to go around it. In the case of Sandy, the blockage was so strong and prominent over the Atlantic Ocean that the storm had no other choice but to hook toward the United States, straight into the Northeast.
To worsen the situation, another storm had also become trapped by the block, ultimately merging with Sandy. This crossbreed’s size grew in terms of diameter,
and its wind field at one point measured 870 miles across, the largest in recorded Atlantic history.
On Oct. 29, 2012, Sandy made landfall near Atlantic City, NJ. Just beforehand, over cooler northern waters, the storm transitioned from a hurricane to a post-tropical cyclone. This change, along with its combination with another storm, led meteorologists to deem the unique system a “Superstorm.”
A peak wind gust of 90 MPH was reported in Islip, NY. In addition, a recordshattering storm surge was seen in the New York City harbor at 13.88 feet. Subways, tunnels, and streets were flooded in the Big Apple while beach erosion destroyed the New Jersey Coastline.
Furthermore, the storm produced enough cold air to cause snow in the Appalachian Mountains, and a massive top total of 36 inches in West Virginia and North Carolina.
In Pennsylvania, schools and transportation were shut down. The Pottstown area received about 5 inches of rain as trees were downed, power was knocked out, and flooding of the Schuylkill River was reported throughout the town. In Berks County, one man died after a tree fell on his home. A total of 14 people died across Pennsylvania.
All in all, Sandy is the fourth costliest hurricane in US history, causing a total of $78.7 billion in damage.
To recap, two recordbreaking storms hit the
area in back-to-back years. The storms were also opposites, with polar and tropical origins respectively. However, fall weather is notoriously variable.
As advancing cold air competes with warm air masses to our south, the orientation of the jet stream changes, which ultimately brings many types of robust storms across our area. These have ranged from severe thunderstorms to snow.
At the same time, hurricane season does not end until November each year. The chances of many factors coming together to lead a storm to hook into the Northeast are in general slim, a one in 700 chance to be exact. Yet in 2012, Sandy proved that this chance was not zero.
So now, 10 years since 2011, it is important to reflect on the Pottstown area getting a taste of two hot and cold storms — literally — when fall weather was simply in its usual high gear.