Hurricane Alley

[caneman]

OK I give up. 10 years ago people who lived in the Carolinas were calling the Carolinas - Hurricane Alley because of all their Hurricane activity. People will believe what they want to believe. And it just doesn't matter.

[bayway]

Canemane said "OK I give up. 10 years ago people who lived in the
Carolinas were calling the Carolinas - Hurricane Alley because of all
their Hurricane activity. People will believe what they want to believe.
And it just doesn't matter Hurricane Alley is a phrase the Media like to
throw around."

If CNN, Fox News or any other media outlet says "Such and
such area is the Hurricane Alley" does that make it so? I say
no. If you would like to study yhr numbers and present a
case... this would be a good thead to do that in.

[MWatkins]

In the past 40 years... There has been a 120 mile strech of the US coast that has
by far taken more big direct hits than any other. 5 majors and a cat 2. It's not Florida.
This 120 mile strech is actualy on par with the entire Fla coast (well over 500 miles).
It's the Mississippi Alabama coast. Waveland to Orange Beach.
I may be mistaken, but I belive there is no 120 mile strech anywhere else in the Con.
US that has seen a landfall count like this in the past 100 years. And this all happened
in 40. Yikes.
I would venture to guess that a vast majority of the genral public would guess
SE Fla... and thier last guess would be MS-AL coast.

Does that paticular area have more strikes in the last 40 years than all of coastal florida?

I don’t know what the conclusion is, statistically. Are you saying that paticular area is more at risk than any similarly sized area in peninsular Florida?

Taking only the last 40 years…when landfall data goes back much futher, is a flawed way of looking at the numbers.

Take the example of a coin. If it is equally weighted…over a long period of time…heads and tails should come up an equal number of times. But in any short term…variation can happen. Hey I have a coin in my pocket…I think I will flip it 10 times and record the results:

1. Heads
2. Heads
3. Heads
4. Tails
5. Tails
6. Tails
7. Tails
8. Tails
9. Heads
10. Tails

Had a little short-term variation there. 60% tails. What your argument does…however…is take flips 4 to 10 and attempts to draw a conclusion from them…

“6 out of the last 7 flips were tails…therefore tails will come up more often than heads. This should surprise people because I bet they think heads and tails come up equally”.

There is more data available that tells a better picture…but it is getting left out IMHO…

MW

[caneman]

In the past 40 years... There has been a 120 mile strech of the US coast that has
by far taken more big direct hits than any other. 5 majors and a cat 2. It's not Florida.
This 120 mile strech is actualy on par with the entire Fla coast (well over 500 miles).
It's the Mississippi Alabama coast. Waveland to Orange Beach.
I may be mistaken, but I belive there is no 120 mile strech anywhere else in the Con.
US that has seen a landfall count like this in the past 100 years. And this all happened
in 40. Yikes.
I would venture to guess that a vast majority of the genral public would guess
SE Fla... and thier last guess would be MS-AL coast.

Does that paticular area have more strikes in the last 40 years than all of coastal florida?

I don’t know what the conclusion is, statistically. Are you saying that paticular area is more at risk than any similarly sized area in peninsular Florida?

Taking only the last 40 years…when landfall data goes back much futher, is a flawed way of looking at the numbers.

Take the example of a coin. If it is equally weighted…over a long period of time…heads and tails should come up an equal number of times. But in any short term…variation can happen. Hey I have a coin in my pocket…I think I will flip it 10 times and record the results:

1. Heads
2. Heads
3. Heads
4. Tails
5. Tails
6. Tails
7. Tails
8. Tails
9. Heads
10. Tails

Had a little short-term variation there. 60% tails. What your argument does…however…is take flips 4 to 10 and attempts to draw a conclusion from them…

“6 out of the last 7 flips were tails…therefore tails will come up more often than heads. This should surprise people because I bet they think heads and tails come up equally”.

There is more data available that tells a better picture…but it is getting left out IMHO…

MW

Thank you Mike you expalined it far more eloquently, scientifically and patiently than I did.

[bayway]

I also provided data back 80 years and we are reviewing 120 year data.
keep in mind that much of the data beyond 80 years get scetchy.

please feel free to do some research yourself and report results here!

[bayway]

In the past 40 years... There has been a 120 mile strech of the US coast that has
by far taken more big direct hits than any other. 5 majors and a cat 2. It's not Florida.
This 120 mile strech is actualy on par with the entire Fla coast (well over 500 miles).
It's the Mississippi Alabama coast. Waveland to Orange Beach.
I may be mistaken, but I belive there is no 120 mile strech anywhere else in the Con.
US that has seen a landfall count like this in the past 100 years. And this all happened
in 40. Yikes.
I would venture to guess that a vast majority of the genral public would guess
SE Fla... and thier last guess would be MS-AL coast.

Does that paticular area have more strikes in the last 40 years than all of coastal florida?

I don’t know what the conclusion is, statistically. Are you saying that paticular area is more at risk than any similarly sized area in peninsular Florida?

Taking only the last 40 years…when landfall data goes back much futher, is a flawed way of looking at the numbers.

Take the example of a coin. If it is equally weighted…over a long period of time…heads and tails should come up an equal number of times. But in any short term…variation can happen. Hey I have a coin in my pocket…I think I will flip it 10 times and record the results:

1. Heads
2. Heads
3. Heads
4. Tails
5. Tails
6. Tails
7. Tails
8. Tails
9. Heads
10. Tails

Had a little short-term variation there. 60% tails. What your argument does…however…is take flips 4 to 10 and attempts to draw a conclusion from them…

“6 out of the last 7 flips were tails…therefore tails will come up more often than heads. This should surprise people because I bet they think heads and tails come up equally”.

There is more data available that tells a better picture…but it is getting left out IMHO…

MW

Why is NOAA making maps like this http://www.nhc.noaa.gov/gifs/hurr-uslan ... 950-06.jpg
56 yrs. ?
They must be as foolish as I am.... studying recent data. We must be idiots!

[bayway]

here's another one! man... that darn NOAA and me... fools...
http://www.nhc.noaa.gov/gifs/strikes_us.gif

do I need to belong to a click or have more than a certain number
of posts before I can do research and post?

[miamicanes177]

do I need to belong to a click or have more than a certain number
of posts before I can do research and post?

If memory serves me correct, last year the board did away with keeping track of a persons post count. Could someone tell us why they have been brought back?

[MWatkins]

I also provided data back 80 years and we are reviewing 120 year data.
keep in mind that much of the data beyond 80 years get scetchy.

please feel free to do some research yourself and report results here!

There are some really smart people who have already done this research. They express this in a long-term probablility called a hurricane return period. Using statistical methods...they have calculated the average number of years between a hurricane passing within 65 nautical miles of a coastal location.

For a category 1 hurricane:

http://www.nhc.noaa.gov/HAW2/english/ba ... 1_gulf.gif

Note the return period for SE and SW Florida is more frequent than the MS/AL coastal areas...

Once you get to category 3...the disparity grows significantly:

http://www.nhc.noaa.gov/HAW2/english/ba ... 3_gulf.gif
When you think about it…the closer to the tropics you get…the more hurricanes one would expect to experience.

South Florida is sticking out in the tropics…that area of the Gulf Coast is way up near 30W. Shallower water…cool shelf water…more westerlies to contend with…the propensity for larger systems to draw in more stable land-based air as they approach…etc all would suggest from a meteorological perspective that the Upper Gulf Coast would experience less hurricanes and surely less intense hurricanes over time than would S Florida…with deep warm water and moist air on all three sides…further removed form the westerlies and closer to the deep tropics…

However…I would still be interested to see what you find. Of course there is a lot of detail work that has to go in (how do you define a strike, what years go in the dataset, how do you account for variance and years not in the dataset etc).

The methodology for HURISK program can be found here:

http://www.nhc.noaa.gov/HAW2/english/ba ... turn.shtml

MW

[bayway]

I'm using the Direct Hit number... not brushes within 60 mile number.

We all know that there are many small storms that
truely don't have a direct impact on a specific area
if it passes 40 to 60 miles away. Especiually is you are
in the weaker quad. I have seem MANY in our area alone
that were nothing more than an evacuation at most. Not that
evacuations aren't imoportant.

[x-y-no]

Rely on data collected from reliable sources. Information is pretty clear.

http://www.nhc.noaa.gov/pastprofile.shtml

http://www.hurricanecity.com/Rank.htm

based on the map from your reliable source... past 80 years...

http://www.nhc.noaa.gov/gifs/strikes_egulf.gif

Monroe Dade and Broward (200 miles) 64
Waveland to Destin (200 miles) 78

Any 120 mile strech between Key West and Palm Beach
doesn't have as many hits as between Waveland and Orange beach
in the past 40-80 years.

Hang on now ...

It's not at all clear to me that one can simply add up all the numbers to get a total for a particular stretch of coast. Since this map goes by county, are we not counting one storm multiple times if, for instance, it strikes Plaquemines, St. Bernard, Orleans, St. Tammany and Handcock? Would it not be counted five times by this method?

I'm not claiming here that your original assertion was false (I haven't attempted to replicate your research) but only that this particular method with this data is questionable.

[Ivanhater]

and now all the way to destin is being added....which is 3 costal Florida counties, I just dont know how the research is being done here, what are the guidelines?

[bayway]

no... each storm only counts once.

[bayway]

and now all the way to destin is being added....which is 3 costal Florida counties, I just dont know how the research is being done here, what are the guidelines?

someone was trying to compare the original 120 miles with key west to ft. lauderdale (200 miles).
so I added 80 miles for comparison

[x-y-no]

no... each storm only counts once.

Forgive me, but how do you know this?

For instance, Orleans Parish is shown as having five hits. How does a storm strike that parish without first striking one of the neighboring parishes? And in that case how is it decided to assign the strike to just one parish?

[mf_dolphin]

Bayway was a formerly banned member who tried to sneak back on so his account has been terminated. The discussion can continue but the author won't be here

[mobal]

As a new person here I did a little bit of research on this forum subject. I hate that a banned persons subject prompted such...

Here is a link that I thought was interesting:
http://www.ncdc.noaa.gov/oa/climate/sev ... tml#latest

http://www.ncdc.noaa.gov/oa/climate/severeweather/hurricanes.html#latest

[Recurve]

Bayway was a formerly banned member who tried to sneak back on so his account has been terminated. The discussion can continue but the author won't be here

Thank you. Was getting a little heated. But it's interesting.

And "hurricane alley" is a non-scientific phrase, mixes perception and feeling -- to say if a metaphor like hurricane alley is "true." That Gulf stretch is hurricane alley in one period; proves something, not probability, as MW showed.

I listed Fort Lauderdale to Key West because I knew of the run of 20th century storms. I live about midway between where Labor Day 1935 and Andrew hit, only 50 miles apart, and 3 miles from Betsy's landfall. That's two Cat 5s and a Cat 4 (Betsy was 35 nm from Key Largo, 3 am 9/8/65, with a 40-mile eye, max winds estimated 120-140 mph, according to NWS advisory).

Has another 50-mile stretch had two 5s and a Cat 4, 30 or less years from one to the next?
But that doesn't prove anything.
It's kinda fascinating and keeps me mindful from June 1 to Dec 1 though.

That's the real point of the "hurricane alley" phrase. Might as well apply the label to the Keys and south Florida, don't want anybody to think the area isn't a sitting duck.

[MiamiensisWx]

Recurve,

I'll offer a friendly clarification with respect to Betsy's intensity. I just wanted to correct some information. According to this official list, Betsy is clearly listed as a Category 3 at its south Florida landfall. The large RMW, pressure gradient, and 954 mbar pressure would suggest a storm within this intensity. Most sources (from my experience) estimate Betsy's top sustained winds in Florida at 105 to 115KT (120 to 132 mph). This is the equivalent of a Category 3 hurricane. In most of the higher estimates, the 115KT has been rounded to 130 mph (borderline threshold between Category 3 and 4). I believe that Betsy featured a large windfield, so it is no great surprise that Miami-Dade County received some significant effects from this storm.

[Berwick Bay]

Question: In regards to S Fl landfalls as recorded in the research. Wilma strikes the SW Fl coastline (Gulf of Mexico). Of course she moves over the penninsula bringing hurricane force winds along the S Fl Atlantic coastline also. So Wilma then is included in the landfall list for the Atlantic Coast too? Suppose Wilma was counted only for the stretch of coastline which received the original hit. Would the disparity change the numbers in regard to Fl as being the Hurricane Capital of the U.S.?