Tremendous Thaw, Horrible Flooding After the Blizzard of '96
January 18, 2013; 4:54 AM
The Blizzard of '96, which was a blockbuster snowstorm, and arctic cold hammered the Northeast U.S. early in January of 1996, before the pattern changed abruptly with deadly consequences.
A massive January thaw, snowmelt and a quick-hitting, intense rainstorm led to extreme flooding across the region during the middle of January.
According to the National Oceanic and Atmospheric Administration, flooding in January 1996 claimed 33 lives.
New Record Crests Set During January '96 Thaw
Compared to Normal
at Williamsburg, Pa.
at Dixon, Pa.
"There was 2-3 feet of snow on the ground in Pennsylvania," AccuWeather Expert Senior Meteorologist Dave Dombek said. "A big warm-up followed and then at the end of the week a big rainstorm came. It looked like a given that things were going to get bad. I've never seen snow disappear so fast."
Setting the Stage
Three snowstorms, including the Blizzard of '96, left deep snowpack across portions of the Northeast during the first half of the month. According to NOAA, snow depths of 2-3 feet were common from central Pennsylvania into New York.
Philadelphia, the hardest-hit city from the Blizzard of '96, received its biggest snow ever from one storm, nearly 31 inches. For the entire month of January, Philadelphia's total snowfall was 34 inches, more than five times the normal monthly snowfall of 6.5 inches.
January 1996 Snowfall Compared to Normal
Compared to Normal
January Thaw, Massive Snowmelt
Following all of the snow, it was like a switch was flipped with the weather pattern. Record-challenging warmth spread into the East during the second half of the month.
Temperatures were below normal in Philadelphia through Jan. 16, 1996, before the significant warming took place. Temperatures went from as much as 20 degrees below normal during the first part of the month to as much as 22 degrees above normal during the second half of the month.
Highs climbed into the 50s and 60s across much of the Northeast. In Philadelphia, highs on Jan. 18 and Jan. 19, 1996, soared to 58 degrees F and 62 degrees F, respectively.
Moisture in the air and wind blowing contributed to even faster snowmelt.
"Snowcover will melt fast when the humidity is high and the wind is blowing," AccuWeather Expert Senior Meteorologist Henry Margusity said. "Light winds and low humidity will allow evaporational cooling to occur millimeters above the snow cover, which creates a cold blanket above the snow. When the wind blows and the humidity is high, that cold blanket of air is removed allowing the higher-humidity air to melt the snow."
The high snowpack generally melted over the course of 18-30 hours.
Ice jam flooding was a problem along many area rivers and streams, since they were icy before the rapid thaw hit.
While flooding was almost a sure bet from quickly melting snow and ice-jam flooding, a rainstorm made matters worse.
"This was one of those cases where we knew flooding was a sure bet," Dombek said. "One of those times where you can go out with bold and definitive statements like 'There will be serious and major flooding.'"
Widespread rainfall amounts of 1-3 inches with local amounts of 5 inches added to run-off, according to Dombek.