Spring Pattern Hinting At 2011 East Coast Hurricane Landfall Potential

[bluewave]

So far this April and May we have seen the 500 mb positive height anomalies near the East Coast shift from south to north.

April 2011

May 2011 so far

All the analog years that featured this April to May northward progression of 500 mb height anomalies had landfalling

East Coast hurricanes with the exception of 1981 which saw a tropical storm.

April composite

May composite

This spring pattern seems to signal that a strong ridge will be present to the north later on during the hurricane season

blocking the recurvature of the tropical cyclones to the northeast.I put together a 500 mb anomaly composite that was

present during the landfalls.

Hurricane Isabel 2003

Hurricane Hugo 1989

Tropical Storm Dennis 1981

Hurricane Donna 1960

Hurricane Carol 1954

Hurricane Edna 1954

Hurricane Hazel 1954

Landfall date composite

[shaggy]

Pretty interesting writeup bluewave. Thanks for posting this and i'll add some stuff i've looked up to help support this idea of a east coast landfall. This is a thread we had in the SE forum that looks at tornado numbers in the spring compared to landfalling hurricanes in the same year.

http://www.americanwx.com/bb/index.php/topic/17984-analogs-and-hurricanes/

[bluewave]

Pretty interesting writeup bluewave. Thanks for posting this and i'll add some stuff i've looked up to help support this idea of a east coast landfall. This is a thread we had in the SE forum that looks at tornado numbers in the spring compared to landfalling hurricanes in the same year.

http://www.americanw...and-hurricanes/

Thanks, Shaggy.Several of those analogs keep popping up from that thread and others.

[rainstorm]

great work.

[matthewweatherwatcher]

I agree this is very good stuff you got here. Keep it up...I think the east coast is going to get a big one this year.

[bluewave]

great work.

I agree this is very good stuff you got here. Keep it up...I think the east coast is going to get a big one this year.

Thanks.

[Cyclonicjunkie]

So it looks like the Bermuda and SE ridge will not be as pronounced this summer?

[bluewave]

The 500 mb composite anomaly present around Irene's landfall matches up with the composite from the earlier analog years.

Analog composite

8/25-8/27/11

[LovingGulfLows]

Incredible to see that you ended up being right.

[Bob Chill]

This is just an excellent thread. The original post makes complete sense and then to see it come to fruition is just excellent for armchair guys like me.

I'm still struggling with things like the MJO and SSW events and how they affect NA patterns but this visual presentation is worth a million bucks.

[QVectorman]

Yeah! Am I missing part of the forum? I was about to start a thread on what happened to all those climate posts in relation to SSW events, QBO, MJO, solar, etc. I was learning so much. I miss the old times like on Eastern where there were great discussions like this by Bluewave, Donsutherland, StormchaserChuck and a few other guys. Where did all those go??

[k***]

The 500 mb composite anomaly present around Irene's landfall matches up with the composite from the earlier analog years.

Analog composite

8/25-8/27/11

The only part that matches is the presence of deep anomalies in the SE from the cane itself...the PAC NW, the lakes, Canada etc all don't match. I know we went round and round about this a couple months ago, but I really don't think this shows anything meaningful other than that landfalling storms look like landfalling storms.

[am19psu]

Yeah! Am I missing part of the forum? I was about to start a thread on what happened to all those climate posts in relation to SSW events, QBO, MJO, solar, etc. I was learning so much. I miss the old times like on Eastern where there were great discussions like this by Bluewave, Donsutherland, StormchaserChuck and a few other guys. Where did all those go??

They'll start reappearing next month when all the winter forecasts start coming out.

[QVectorman]

They'll start reappearing next month when all the winter forecasts start coming out.

Thanks Could of swore last year they were starting to post about this time. But there are really only a hand full I actually I really thought had a solid core of science behind and they use to post throughout the year...I hate to ask about particular members, I see Don Sutherland pop up in another thread today but where is Stormchaser Chuck? Is he bound to a private company and can't post public or is he just MIA?

[Joe1]

To All:

I am a new member to this forum.

I am not a meteorologist. I live on the East coast of the US. I follow the discussions on the latest hurricanes on this site.

Great site with real expertise comments.

What is your opinion of the new item Katia?

Will this thing be anything like Hugo?

[k***]

To All:

I am a new member to this forum.

I am not a meteorologist. I live on the East coast of the US. I follow the discussions on the latest hurricanes on this site.

Great site with real expertise comments.

What is your opinion of the new item Katia?

Will this thing be anything like Hugo?

no.

[CooL]

no.

lol

where do these Hugo rumors come from

[bluewave]

The only part that matches is the presence of deep anomalies in the SE from the cane itself...the PAC NW, the lakes, Canada etc all don't match. I know we went round and round about this a couple months ago, but I really don't think this shows anything meaningful other than that landfalling storms look like landfalling storms.

See the original post.

This spring pattern seems to signal that a strong ridge will be present to the north later on during the hurricane season

blocking the recurvature of the tropical cyclones to the northeast.I put together a 500 mb anomaly composite that was

present during the landfalls.

[bluewave]

Incredible to see that you ended up being right.

This is just an excellent thread. The original post makes complete sense and then to see it come to fruition is just excellent for armchair guys like me.

I'm still struggling with things like the MJO and SSW events and how they affect NA patterns but this visual presentation is worth a million bucks.

Yeah! Am I missing part of the forum? I was about to start a thread on what happened to all those climate posts in relation to SSW events, QBO, MJO, solar, etc. I was learning so much. I miss the old times like on Eastern where there were great discussions like this by Bluewave, Donsutherland, StormchaserChuck and a few other guys. Where did all those go??

Thanks.

[Mallow]

See the original post.

This spring pattern seems to signal that a strong ridge will be present to the north later on during the hurricane season

blocking the recurvature of the tropical cyclones to the northeast.I put together a 500 mb anomaly composite that was

present during the landfalls.

I hate to say it, but I kind of agree with k***.... it seems to me like you have merely a composite of what the 500mb pattern looks like for east coast hurricanes (albeit interesting to look at), and have shown that, not surprisingly, Irene fits that composite. Just because you took the sample of landfalling east coast hurricanes from the specific analog years you found earlier doesn't mean the composite is significantly different than the general composite of "landfalling east coast hurricanes". In fact, the areas that it might be different since they don't have as much of an impact on the path of storms (from the central US west) are actually pretty different.

See what I'm saying, though? In most east coast hurricane landfalls, you're going to have the low height anomalies in the southeast (due to the hurricane itself), and high height anomalies over the northwest Atlantic (the only way to steer the hurricane to the east coast in the first place).

Now, if you instead took a composite of your analog years in all of August/September, and compared them to this August/September's overall pattern, I think you could show more what you're trying to show--that the analog years are actually valid and useful.

[bluewave]

I hate to say it, but I kind of agree with k***.... it seems to me like you have merely a composite of what the 500mb pattern looks like for east coast hurricanes (albeit interesting to look at), and have shown that, not surprisingly, Irene fits that composite. Just because you took the sample of landfalling east coast hurricanes from the specific analog years you found earlier doesn't meant the composite is significantly different than the general composite of "landfalling east coast hurricanes". In fact, the areas that it might be different since they don't have as much of an impact on the path of storms (from the central US west) are actually pretty different.

See what I'm saying, though? In most east coast hurricane landfalls, you're going to have the low height anomalies in the southeast (due to the hurricane itself), and high height anomalies over the northwest Atlantic (the only way to steer the hurricane to the east coast in the first place).

Now, if you instead took a composite of your analog years in all of August/September, and compared them to this August/September's overall pattern, I think you could show more what you're trying to show--that the analog years are actually valid and useful.

The whole point is that the analogs were similar to the general composite since they are part of a pattern which supports landfalling hurricanes.

They represent a subset of the overall number of east coast landfalling hurricane years.

[Mallow]

The whole point is that the analogs were similar to the general composite since they are part of a pattern which supports landfalling hurricanes.

They represent a subset of the overall number of east coast landfalling hurricane years.

But what I'm saying is that, since you only took the composite of the actual dates near landfall, of course it's going to look like "a pattern which supports landfalling hurricanes". It's like if I took a composite of the snowiest periods from some subset of "analog years" (and not necessarily years that were exceptionally snowy) and claimed the analogs supported a pattern which produces snowy periods... all it actually shows is that "this is what a pattern that supports snow looks like". Not that it's any more or less likely that such a pattern will actually occur.

[bluewave]

But what I'm saying is that, since you only took the composite of the actual dates near landfall, of course it's going to look like "a pattern which supports landfalling hurricanes". It's like if I took a composite of the snowiest periods from some subset of "analog years" (and not necessarily years that were exceptionally snowy) and claimed the analogs supported a pattern which produces snowy periods... all it actually shows is that "this is what a pattern that supports snow looks like". Not that it's any more or less likely that such a pattern will actually occur.

In my first post I stated that there would be enough of a ridge to the NE to block a recurve out to sea.

If you take a look at years when the tropical cyclones recurved to the east,then you will see more

of a trough near New England and the Canadian Maritimes.My analog years had the ridge pattern in

place around the time that the storms developed and impacted the east coast.The intervals of duration varied

but the one common denominator is that they coincided with the storms.

[Mallow]

In my first post I stated that there would be enough of a ridge to the NE to block a recurve out to sea.

If you take a look at years when the tropical cyclones recurved to the east,then you will see more

of a trough near New England and the Canadian Maritimes.My analog years had the ridge pattern in

place around the time that the storms developed and impacted the east coast.The intervals of duration varied

but the one common denominator is that they coincided with the storms themselves.

My point is that whether in your analog years or not, times that storms impact the east coast are likely to have that pattern. In other words, the fact that the particular years you are looking at had that pattern at the time of landfall is only a function of the fact that that particular pattern is the most common pattern at the time of landfall, analog years or not.

I don't really have time to explain much better than that right now, but I'm sure I can come up with an analogy a little later that will make it clearer.

[Ellinwood]

Show us the pattern in the 3-7 day period before landfall... would probably be a better composite to compare with rather than the near-landfall heights.

Granted, that's still fairly short-term. I would be looking for the more long-term pattern that's on the order of 3-4+ weeks in order to make a reasonable long-range U.S. landfall potential forecast.

[bluewave]

Show us the pattern in the 3-7 day period before landfall... would probably be a better composite to compare with rather than the near-landfall heights.

Granted, that's still fairly short-term. I would be looking for the more long-term pattern that's on the order of 3-4+ weeks in order to make a reasonable long-range U.S. landfall potential forecast.

You can see the blocking to the NE of Irene,Isabel,and Hugo during the week leading up to landfall.

Different degrees of blocking leading to the individual tracks of each.

Irene

Isabel

Hugo

[Ellinwood]

You can see the blocking to the NE of Irene,Isabel,and Hugo during the week leading up to landfall.

Different degrees of blocking leading to the individual tracks of each.

The ONLY things in common with those three examples are the blocking ridge in the NE and a cool NW Canada. There are no long-term signals that you can derive from those maps.

[CandymanColumbusGA]

You can see the blocking to the NE of Irene,Isabel,and Hugo during the week leading up to landfall.

Different degrees of blocking leading to the individual tracks of each.

Irene

Isabel

Hugo

You illustrated that we need some sort of blocking high to get a hurricane to ride up the eastern seaboard... This is great for Short-Term... NOT Long-term. That's what Ellinwood and Mallow are pointing out. Try extending the periods you have to four weeks BEFORE the storms formed and see if there is a correlation to what you posted in May.

[bluewave]

The ONLY things in common with those three examples are the blocking ridge in the NE and a cool NW Canada. There are no long-term signals that you can derive from those maps.

What did the spring patterns have in common those years with this year?

[Ellinwood]

What did the spring patterns have in common those years with this year?

I should have been clearer in my argument... while it seems you have found a correlation with late-spring anomalies and EC landfalls, your conclusion was quite flawed:

This spring pattern seems to signal that a strong ridge will be present to the north later on during the hurricane season blocking the recurvature of the tropical cyclones to the northeast.

All you did was prove that just ahead of a landfalling hurricane there was a ridge present in the NE. I looked at the 7 EC landfalls in your OP and looked at the 1 month height anomalies prior to the landfall threat... only 2 of them showed the NE ridge in the long-term pattern. Others were neutral, others had a NE trough. This would indicate that the ridge is more transient and short-term in nature ahead of an EC landfalling 'cane (or at least the ones that you listed). There's (almost?) always a strong NE ridge at some point during the hurricane season... it's just a matter of lining that up properly with a TC.