Monday, January 18, 2016
Remembering Winter Floods of January 1996 (Pennsylvania)
Some of you know that I have gotten interested in weather because of my interest in aviation and wildland firefighting. While this is not a weather blog, I do like to post articles from time to time on weather events. I don’t believe that I have posted an article on an historical weather event, but I feel compelled to do so today. Before I get to the point of this article, I will briefly set the stage by offering some memories of some snow and rain storms in January 1996.
Being that I have been living in New Jersey for quite awhile, there are certain weather events that stand out to me. One of those was a Blizzard on January 6-7, 1996. I was not in New Jersey at the time, rather I was driving to northern New England that day to visit some relatives, literally playing tag with the northern edge of the Blizzard until I got north of Springfield, MA. I spent about 4 days in northern New England where this snow storm dumped only a couple of inches. However, like many, I followed the Blizzard on TV. I knew that the Blizzard dumped 2 feet plus of snow in the greater New York City metro area, shutting almost everything done for two to four days depending on your location. When I got back to New Jersey sometime the following the weekend (on or about January 13th), there was still a significant amount of snow left along with some very impressive snow drifts. I had no driveway so usually parked on the street in front of my apartment. But no street parking was to be had. Fortunately, a nearby neighbor had room in their driveway and let me park there.
A few days later, probably on January 18-19, 2016, it warmed up and the snow melted, and it rained. If memory serves, the town and the residents were pretty good at removing the snow from the storm drains so the snow melt had a place to go. At least the water had a place to go where the storm drains were uncovered. I recall being inconvenienced by the urban street flooding. But it was not a big deal.
Not so in other areas in the Mid-Atlantic. I do recall hearing about major flooding in Pennsylvania and upstate New York, among other places in the Mid-Atlantic. I remember thinking that I was pretty darn lucky. Those floods are now known as the Winter Floods of January 1996. The NWS Mid-Atlantic River Forecast Center (NWSMARFC) provides river and hydrologic forecasts many of the areas flooded that January. See the map on the NWSMARFC home page for a map.
In remembrance of the 20th anniversary of the Winter Floods of January 1996, the NWSMARFC and the NWS State College, Pennsylvania has put together a nice webpage about the Winter Floods of January 1996, you may want to check out their additional links for more information. I am focusing here on Pennsylvania. New York, Virginia and to a lesser extent New Jersey were among the areas affected by these floods. The stage for these floods was set by some 30 to 40 inches of snow in areas of Pennsylvania during the Blizzard of January 6th and 7th. On January 19th temperatures warmed up to the low 60s and it rained, a lot of rain with winds gusting up to 38 mph. The snowpack was already melting because of the high temperatures and when you add 3+ inches of rain to that, problems ensued. The Rivers rose to and beyond flood levels. Add to that ice jams on the Rivers and the stage was set. Twenty lives were lost in Pennsylvania and damage from these floods was in the a billion dollars in Pennsylvania alone. Many bridges were damaged. (For more information see a USGS report on the January 1996 floods in Pennsylvania and this report from the Susquehanna River Commission).
I know a little about different types of ice jams on rivers from being an ice observer for my local NWS office, see for example this webpage on different types of ice jams from the NWS office in Great Falls Montana. Ice jams can be very dangerous and can cause damage to bridges and other infrastructure in or adjoining a river. I know enough to stay off a frozen river, including a river with ice jams.
When I saw a video of the partial collapse of the historical Walnut Street Bridge over the Susquehanna River in Harrisburg during the Winter Floods of January 1996, I knew that I had to write this article and share this video with you (embedded at the end of this article). I am not a hydrologist nor am I expert in ice jams, and I am not an engineer. However in watching the video it seems to me that the ice jam on the Susquehanna probably lead to a partial collapse of the bridge that was already weakened by Tropical Storm Agnes in 1972. If you want to read more learn the Walnut Street Bridge go here (Bridgehunter.com) to see a nice photo gallery of the Bridge before and after the 1996 floods, some history of the Bridge, and an embedded google map. You might also want to check out this blog article on the Bridge written by a blogger who visited Harrisburg and took some photos of the Bridge in January 2015.
To the best of my knowledge, the damaged sections of the Walnut Street Bridge have not been repaired to date.
Please stay safe this winter, stay off of ice-covered rivers and stay well away from a river with an ice jam.