Tuesday, October 30, 2012

Summarizing Sandy

As a meteorologist, who grew up in South Jersey, it really didn't seem plausible that we'd see this one day. I certainly never thought we'd see it in late October and of the scope and scale that we witnessed yesterday. But we did. I don't want to make this post a pontification or anything. But I will wind through some of the aspects of this storm, hit the highlights, and post a little memorable meteorological imagery. There will be more written in the days ahead, so consider this the first of several discussions.

The Forecast
As meteorologists, we usually say that when the models all predict a big event, there's going to be a big event. I can see evidence that the European model had a threat starting from its 12z run on October 19th, where on Monday morning it indicated a deep low/tropical cyclone 300-400 miles east of the GA/SC coast drifting north. It really wasn't until the 21st's 12z run that the Euro came around to a direct East Coast threat of a major low pressure system. Still, to hint this 10 days out...is remarkable. Many will bash the GFS model for constantly hooking the storm out to sea or way north into Nova Scotia and New England, however, it too had its sights set on Sandy from 9-10 days out. The bottom line is that the majority of global modeling suggested that a major to historic storm system was going to occur on the East Coast 7-10 days before it occurred. The March 1993 Superstorm was much the same.

Credit the models, but also credit the meteorologists interpreting this storm. The National Hurricane Center may have taken some grief for the mess with post tropical vs. tropical advisories, warnings, and definitions, but their tracks from over the weekend and even back to Friday were top notch. The forecasts from many a private sector and NWS meteorologist, the warnings that were put out, etc. were fantastic, timely, and for the most part accurate. A special credit to the local forecast office meteorologists at the National Weather Service (specifically locally at Mt. Holly), who by having to issue all the watches, warnings, and advisories in light of the NHC stopping north of North Carolina, they did absolutely tremendous work in all aspects of the storm and did what they could to help save lives. Eric Berger of the Houston Chronicle discusses some of this more, and also shares at least some honest criticism, specifically with regard to the early storm surge forecasts.

The forecast for rainfall fell into the 6-12" range at varying lead times. In New Jersey, the highest total thus far is 11.91" at Wildwood Crest. In the immediate Philadelphia area, 5.90" fell near Landenberg in Chester County. We saw 7.65" near Newark, DE and 10.20" in Georgetown, Sussex County, DE. Rainfall forecasts were (for the most part) excellent.

Wind Gusts
In Jersey, wind gusts hit 89 mph in Surf City, 88 mph in Tuckerton, 87 mph in Newport, Cumberland County, 81 mph in Dennisville, and 77 mph in Atlantic City. Around Philly, the Northeast hit 70 mph and the Airport hit 68 mph. Trenton also hit 68 mph. Other gusts were 85 mph in Plum Island, NY, 85 mph in Madison, CT, 90 mph at Islip, NY, 88 mph in Montclair, NJ, and 96 mph 70 feet above Eaton's Neck, NY.

I think the wind may have come in even a bit stronger than many expected, but the widespread 40-60 mph winds verified, with many gusts above 65 mph from this storm. This is quite possibly one of the most wide reaching storms you will ever see in terms of wind gusts and power outages. Close to 9 million customers, at last count, had lost power from the storm. Predictions in the run up to the storm were for 10 million. Very close.

Storm Surge
I will post some of the graphs below. But needless to say, north of Atlantic City (and even there to points south), this was just an unspeakable storm surge event. The Integrated Kinetic Energy (IKE) for Sandy at peak rated a 5.8/6 for surge potential, placing it above any storm we've ever had in the Atlantic Basin, including Katrina, Andrew, and Ike. At landfall it rated around 5.2-5.4, which would put it right in the midst of that company. IKE is calculated by taking into account the size and amount of "energy" within the surface wind field. The paper defining IKE can be found here. More details including archives of data back to 1994 (and a handful of storms before then) can be found here. The storm surge was massive and devastating and will take a very long time to recover from, especially for places in Northern NJ, New York, and New England.

Final Thoughts
Sandy will go down in history and lore, mentioned in the same breath as 1938, 1944, Hazel, Carol, the 1950 Appalachian Superstorm, and other storm you can think of to have impacted the Northeastern United States. It is a tragedy, devastating, disheartening, and any other adjective you can use to describe. As someone who grew up at the Shore, I take a unique, heartbroken viewpoint in seeing some of the photos of damage, mayhem, etc. But despite all of that, I think there is a bright spot to some extent. Had this occurred 50 years ago, it is possible that hundreds, if not thousands could have perished. Thanks to the marvels of modern meteorology, while not perfect, we were able to have plenty of advance notice, and the process hopefully saved lives in the end. Hopefully lessons are learned to mitigate such a terrible disaster in the future, as best as can be done. And hopefully the recovery moves expeditiously, so we can all one day tell others about the Great Hurricane Sandy of 2012.

NOAA Video of Sandy using one minute Super Rapid Scan data as the storm approached NJ

Sandy sits offshore of North Carolina with an Integrated
Kinetic Energy of a record 5.8/6.  Credit: NOAA
Tidal Surge Charts from top to bottom:
Philadelphia 10.62'
Cape May 8.91'
Atlantic City 8.90'
Sandy Hook 13.31' before the gauge broke.
New York, NY 13.88'