Urbania, Nova Scotia- The Tidal Bore Rafting Park on route 215 does a good business with tourists looking to experience first hand a rarity in rafting worldwide... riding a tidal bore.
What is a "tidal bore"?
A tidal bore is a rare natural phenomenon occurring when an incoming tide temporarily reverses the flow of a river, and appears as a crest of water traveling upriver.
The highest tides on Earth occur in the Minas Basin, the eastern extremity of the Bay of Fundy, where the average tide range is 30' and can reach 50' when the various factors affecting the tides are in phase. (see photos)
The primary cause of the immense tides of Fundy is a resonance of the Bay of Fundy-Gulf of Maine system. The system is effectively bounded at this outer end by the edge of the continental shelf with its approximately 40:1 increase in depth. The system has a natural period of approximately 13 hours, which is close to the 12h25m period of the dominant lunar tide of the Atlantic Ocean. The normally gentle Atlantic tidal pulse pushes the waters of the Bay of Fundy-Gulf of Maine basin at nearly the optimum frequency to cause a large to-and-fro oscillation. The greatest slosh occurs at the head (northeast end) of the system in the Minas Basin.
But what happens when the Atlantic tide is not-so-normal? Like when a named Hurricane is offshore?
In Canada on the Shubenacadie River, the tidal bore and rapidly rising tide results in extremely turbulent waters. It is here where experienced guides offer a safe but exhilarating river rafting adventure and an opportunity to experience the power of the tides first hand.
Similar to tide times, tidal bore times for several locations may also be predicted. The South Maitland Tidal Interpretive Park offers a view of Nova Scotia's largest river (the Shubenacadie River) where visitors may see the tidal bore at "...the following estimated times (Note: Visitors are encouraged to arrive 15 minutes in advance to avoid missing this natural phenomenon.)..."
For Sunday, August 23rd, 2009 it lists 1:30 P.M. The Weather Underground shows Hurricane Bill arriving at about the same time. (see chart)
According to MSNBC, "Canadian authorities issued selective hurricane watches and tropical storm warnings for its Atlantic maritime provinces, specifically parts of Nova Scotia, Prince Edward Island and Newfoundland. On its current track, Bill could threaten some oil and natural gas platforms and refineries in east Canada."
No mention of the effect on the world-famous Bay of Fundy tide.
Roads in coastal North Carolina have already been flooded with up to three feet of water, and a look at the satellite image shows the storm passing not nearly as close to the Carolina Outer Banks as it will tomorrow to the Bay of Fundy.
So, that raises the question; Will Bill produce a world-record tidal bore racing upstream?
I called the office of Lisa Gersh, Interim CEO at the Weather Channel in Atlanta, Georgia, and never got a return call. But upon calling Melissa Medori, Associate Manager Public Relations, I did finally field a return call from a staffer who appeared to know nothing of this situation Sunday. Will Jim Cantore broadcast live Sunday afternoon from the Bay of Fundy? Who knows, but whatever happens, it likely will not occur again for quite some time.
Hurricanes are not normally at strength when making landfall in Canada. Hurricane Hazel in 1954 left 81 dead in the Canadian provinces (killing 35 on a single Toronto street). It was Hurricane Juan of September 23, 2003 that is generally thought to be Canada's most widely destructive Atlantic hurricane in over a century.
Juan thankfully killed only 8, but caused over $200 million in damage. Power outages in Nova Scotia and Prince Edward Island left over 300,000 Canadians without power for two weeks. Many marinas were destroyed and many small fish craft were damaged or sank. "Hurricane force gusts were reported as far out as 100 miles (160 km) on either side of Juan at landfall with an astounding peak gust of 144 mph (229 km/h) (equivalent to a category 4 hurricane) recorded in Halifax Harbour, although it was a Category 2 at landfall with 100 mph (160 km/h) sustained winds." (www.ec.gc.ca)
Hurricane Bill is expected to be rated just under Category 1 tomorrow. And The tides are a bit different in the Bay of Fundy and Halifax Harbour.