Life threatening conditions along East Coast

>>> brian williams , nbc news, new york .

>>> well

>>> welcome back. we pursue the big story the march of hurricane irene , as it churns up the east coast of the united states . this is one of the local radars. look at the size of this storm . it is now possible to say elements of this storm , bands of this storm go from north carolina , clear north to canada. it is that large. it is slow-moving. it's easily 500 miles across. we want to start off this half-hour with the very latest on the storm , its strength, its size, its location, to the weather channel headquarters we go. our friend brian norcoss, veteran meteorologist. set the scene. beginning with this, we have been saying a category 1 storm . and it is. you have been saying that number is really irrelevant and immaterial given the energy and the size of this storm , correct?

>> yeah, that is correct, brian . the category of the storm has to do with the top winds right near the center. the thing is the winds with this storm are spread out over hundreds of miles. when you take all the wind energy , put it into the motion, and you drive the water you get the ocean moving toward the shore. that is going to come up over the shore. there will be life threatening conditions up and down the coast. and you take all right energy over the land and you get inundation, raining flooding and everything bad that goes with that. let's take a look at the radar you were showing in detail here. let me show you really what the threat is here tonight. because here is chesapeake bay . and very unfortunately, here is the center of the hurricane. and just emerges off of land. you see it right there. that is the center. again. chesapeake bay . and it is driving the water into chesapeake bay . like your situation in new york . high tide is going to come into play here. when the center gets up to about to there where they will have the worst effects from the hurricane that is when their high tide comes and the water there could be 11, 13 feet. and then on up the coast, south jersey , may catch a break because low tide will be there. but then on up further north. in new york , again, where al roker is there, on long island, and the north part of the jersey shore that you love so much, of the the -- unfortunately, high tide will drive the water, and the l created by long island and new jersey. as you say this has spread all the way north. here is the satellite picture . just showing you this expansive area of cloudiness and storminess that is going to be relentless moving north, brian .

>> brian , normally a storm moving out from land as much as the outer banks can be considered hard land on to the water is a very bad thing for strengthening. does it help at all that -- while the water is at its height, late summer, this is not exactly warm water up here in the northeast?

>> yeah, the warm water is not help anything here, brian . there is the water is warm, the atmospheric conditions are so favorable that -- it's just going to keep it going, it may weaken a lit bit, that is just not important.

>> all right, we are just looking to any strands of hope here. all up the coast here not new york harbor . brian , we'll be back