26.8.11

.Irene, Irene.

.Will this be like Earl Schmirl?  People were ALL up in arms about Earl and it never happened.  Ended up passing Nantucket, but did eventually make landfall in Canada.  The culprit of the demise of this hurricane?  Cold water.  Yep folks, the water temps are much colder up here...not like the bath water of the NC coast.  Nevertheless, you never know what will happen and the Northeast is due for a hit.  The last big one was Bob '91.  People still talk about it like it was yesterday.  I am from NC, so when I think of the big one's I think of Floyd '99 or Fran '96.  Great names.  But the old folks in NC always like to talk about Hazel in '54.


.Why are our waters so cold here (relatively speaking)? This is a rough sketch of the Labrador Current meeting the Gulf Stream.  This current, which originates in the Arctic Ocean, is a cold current and the Gulf Stream, which originates at the tip of Florida, is a warm current.  As you can imagine, the Labrador Current has a cooling effect on coastal New England and in the spring it even carries icebergs southward from the glaciers of Greenland.  As the tropical cyclones make their way up the warm Gulf Stream, they eventually meet this colder, albeit weaker, Labrador Current, which can really start to slow a large cyclone.

.interesting fact: the convergence of these currents is why New England is so susceptible to nor-easters

.interesting fact #2: the Gulf Stream's proximity to Nantucket, provides the island with great biodiversity.  The island is the northern most limit for southern varieties of plants, and the southern most limit for northern plants.  Read more on wiki.  Can't wait to go there for Labor Day!

.So the question remains, what will Irene bring?  The above picture shows the various water temps at different weather stations. The water temps close to the coast, range from 70 to 79 degrees, however, at this lone station in the middle of the ocean (Station ID 44008), the water is closer to 68 degrees.  So is that area further out in the ocean, between Montauk and Nantucket, also about 68 degrees? 

.The other thing we know, is tropical cyclones need warm surface water to stay alive, and most will start to dissipate when the water temp is significantly below 79.7 degrees.  Wind shear is another factor in weakening tropical cyclones, but this seems to be a complicated subject and one I don't feel like researching right now.  See wiki for more information.


.Ok, that is all I have for now.  I love weather.

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