There's still not much to talk about the tropical Atlantic today. The Intertropical Convergence Zone (ITCZ), the band of intense thunderstorms that spans the tropical Atlantic between Africa and the Lesser Antilles Islands, has grown more active in the past few days, though. The two tropical waves in the ITCZ closest to the coast of Africa bear some scrutiny this week as they cross the Atlantic. However, none of the models are currently forecasting development of these waves, and there is plenty of wind shear and dry air that will interfere with potential development.
World storm surge records
In preparation for the release of a major new storm surge section of the web site, I've been researching storm surge records. The Bathurst Bay Cyclone, also known as Tropical Cyclone Mahina, which struck Bathurst Bay, Australia on March 5, 1899, is generally credited with the world record for storm surge. The cyclone's storm surge is variously listed at 13 - 14.6 meters (43 - 48 feet). The Category 5 cyclone was a monster--with sustained winds in excess of 175 mph and a central pressure between 880 and 914 mb. Mahina killed at least 307 people, mostly on pearling ships, and was the deadliest cyclone in Australian history. The eyewitness account of Mahina's record storm surge was provided by Constable J. M. Kenny, who journeyed to Barrow Point on Bathurst Bay to investigate a crime on the day of the storm. While camped on a ridge 40 feet above sea level and 1/2 mile inland, Kenny's camp was inundated by a storm wave, reaching waist-deep. On nearby Flinders Island, fish and dolphins were found on top of 15 meter (49 foot) cliffs. However, an analysis by Nott and Hayne (2000) found no evidence of storm-deposited debris higher than 3 - 5 meters above mean sea level in the region. They also cited two computer storm surge simulations of the cyclone that were unable to generate a surge higher than three meters. Indeed, Bathurst Bay is not ideally situated to receive high storm surges. The Great Barrier Reef lies just 20 - 40 km offshore, and the ocean bottom near the bay is not shallow, but steeply sloped. Both of these factors should conspire to keep storm surges well below the record 13 - 14.6 meters reported. The authors concluded that the actual surge from the Bathurst Bay Cyclone may have been 3 - 5 meters. The observed inundation at 13 meters elevation, plus the observation of dolphins deposited at 15 meters above sea level, could have been caused by high waves on top of the surge, they argue. Waves on top of the surge (called "wave run-up") can reach five times the wave height at the shore for steeply fronted coasts like at Bathurst Bay. Since waves in the Bathurst Bay Cyclone could easily have been 3 meters, 15 meters of wave run-up on top of the surge is quite feasible. Since wave run-up doesn't count as surge, the status of the 1899 Bathurst Bay Hurricane as the world-record holder for storm surge is questionable. However, the event is certainly the record holder for the high water mark set by a tropical cyclone's storm surge, an important category in its own right.
http://www.wunderground.com/blog/JeffMa ... rynum=1268
Apparently the storm surge from Tropical Cyclone Mahina is not the highest in the world. It was certainely a strong tropical cyclone with central pressure as low as 880 millibars. It would not surprise me if Katrina produced storm surge as high as 40 feet.
