1821 Hurricane would be much worse than Sandy

[chubbs]

A lot of it is indeed a result of geologic/topographical changes. Looks like it's the same group of nutcases going from forum to forum, derailing threads with CC-forum crap.

That type of namecalling is not even worth responding to

[JBG]

Sandy was very much like a 1991 Perfect Storm but much deeper and dominated by the tropical system rather than the baroclinic one like 1991, which ingested Grace into its circulation. There was tremendous divergence aloft over Sandy caused by the negative tilt and then the phase with the system coming out of the Midwest. The -NAO did the dirty work by forcing a NW track. Pure hurricanes aren't the greatest threat up here (i.e. an Irene)-hurricanes really need an assist from mid latitude systems to really be a danger at this latitude. They prevent the east recurve and provide a barrier against weakening from the dry and cold air intrusions from land and cold waters.

 

Needless to say Sandy was unlike any storm I've ever experienced and is the new benchmark storm for this area (1938 becomes worse once into Suffolk County-the effects from Sandy became less severe once you head not far east from here).

Wasn't that the case with Agnes in 1972 as well; a tropical storm (briefly a hurricane) which also retrograded northwestward, up the Hudson Valley and then looping almost southwestward?

[Smoked]

In regards to the return interval of Sandy, I agree with what some others have eluded to: Sandy's intensity may not be a one in 500 year event, but from a dynamical and geographical standpoint it may even have a lower probability of occurrence. Sandy's myriad of characteristics (size, movement, ect..) while coinciding with multiple high tide cycles (at an astronomical high tide no less) in the most densely populated region in the US will be very difficult to replicate. And given that Meteorologists haven't really seen a storm phase this nicely (to my knowledge) ever before Sandy, I would think that calculating a return period for such a storm that we have seen once in our 60-100 years of reliable observations is nearly impossible.

 

Assuming we aren't entering into a climate regime (supported by GW or not) that favors the development of this type of storm, it would be very unlikely that we see a similar storm for a long time.

[DTWXRISK]

 you are missing  a key point. IT  media hype and over warn from IRENE  in NJ  NYC   CT  and Long Island  in late  AUgust 2011.

The decision by NWS/. NHC   to not  go with Hurricane watches and warnings  killed scores of  people .
Most  people were  thinking ..."How bad could this   storm be  if  they are not issuing  watches / warnings...and Irene  
they did issue  watches and warnings  with Irene"

 

A change has been made regarding scenario's like this, thus hurricane warnings will be issued instead of non-tropical warnings.

 

Hurricane warning resonates? Yes, however hurricane warnings were up well in advance of Katrina in 2005, and look what happened there.

[JBG]

you are missing  a key point. IT  media hype and over warn from IRENE  in NJ  NYC   CT  and Long Island  in late  AUgust 2011.

The decision by NWS/. NHC   to not  go with Hurricane watches and warnings  killed scores of  people .

Most  people were  thinking ..."How bad could this   storm be  if  they are not issuing  watches / warnings...and Irene  

they did issue  watches and warnings  with Irene"

I have made that point as well. Irene didn't get dramatic warnings where it had some real impact, such as upstate New York and Vermont. The warmings were "end of the world" type warnings for the New York area, where it was essentially a bad rainstorm. What did exacerbate that was the fact that August had already been a very rainy month. The real threat was never either forecast or if forecast elucidated.

With Sandy the forecasters were better, but Irene caused a loss of credibility. In Sandy they did over-forecast the rain though.