Michael Staton follows Hurricane Analytics on Facebook, and he made a great recommendation for the “storm dashboard” I am developing. He asked “why not also show analog storms along the forecast track for reference”?
I though that was a great idea. I started digging into the data, trying to find the most impact-full way to illustrate historical data without adding too much clutter. Ultimately, I decided on taking a 3 degree radius around the current storm position, in a similar month. However, the historical tracks database goes back to 1851, which is still too much data.
I decided to limit the data to storms since 1970, and I was quite surprised to learn that only 5 storms had reached hurricane strength at some point in their lifetimes, including Sandy, and had passed within three degrees of Sandy’s position on October 26th, 2012 at 8AM EST (26.9N, 76.4W). By the way, the only one that eventually “turned back” to the US East coast was Sandy. Check it out!
This was a much smaller number number than I expected. Curious (and remembering some hurricane history), I looked back in the data set for the previous 43 year period from 1927 to 1969. The contrast was incredible.
In that 43 year period, there were 18 storms that met the same criteria. However, of the 23 storms reaching hurricane strength that passed through this area in October, only one (Sandy) turned back to the US Coast north of North Carolina.
Couple that with the vast increase in coastal development since 1970 and the large and growing population there, and you’ve got a recipe for what happened…a large storm surge which surprised unprepared people.
Northward moving October hurricanes emerging from the Caribbean are not new events. We, here in the US, have just been extraordinarily lucky in the last 43 years.