La Nina/El Nino/Neutral: Long-range Thoughts For 2006

[MiamiensisWx]

Models are now hinting at a long-term potential pattern change, with a negative NAO and heat ridge over the Great Plains forecast to set up. This type of pattern tends to be typical of a La Nina year. It also tends to result in a pattern in which we have a strong Atlantic ridge that is located further to the east as the Azores High, resulting in a 1996/1999 (not 2004/2005) pattern. This tends to mean a strong trough located right off the southeast/eastern U.S. coast, meaning that most storms (which will be more Cape Verde-type storms that form far east in a La Nina pattern like this) will likely curve away from Florida and miss the U.S. eastern coast or, if they make landfall, hit the Carolinas (e.g., a 1996/1999 pattern; both were La Nina years). This tends to be some good news for eastern/western Florida and the Gulf coast, since the two main steering ridges will be further to the east and west; however, this pattern means the western Gulf (Texas and Mexico) tend to be under the gun, though. The big question is this: will this pattern last into July/August/September? That is too early to tell. This pattern may change by then; so far, though, it may be some good news for you and us if this pattern holds! It will be VERY bad for North Carolina, the Leeward Islands, and far western Gulf (Texas and Mexico), however.

NOTE - As a side note, while east hits are less common in La Nina years, Florida tends to receive more southwest hits during La Nina years than during neutral/El Nino years. Maybe this a balancing effect! Don't let your guard down!

Hope this has helped. Any thoughts?

You can see a very clear climatological pattern from the La Nina years of 1996 and 1999 on the maps below...




These two years had some of the strongest La Ninas in recent years (preceeding and following the great 1997 to 1998 super El Nino).

Now, let me get to the point: based on my observations above, I lead myself to this conclusion that answers questions on steering patterns. It is NOT so much the La Nina ITSELF that causes these types of troughiness patterns to unfold; rather, it is the FACTORS that are in place that TEND to be more PROMINENT in La Nina years (including strong La Nina years like 1996/1999). Factors such as negative NAO patterns, Pacific SSTs/anomalies patterns, Great Plains ridging, and western U.S. ridging tend to be more prevelant in La Nina years. The big question is this: why? More studies need to be done, but I think we are just beginning to understand the patterns - short-term and long-term - and climatological activity that shapes steering and climatological patterns each hurricane season. Knowledge about this will only become more crucial in this and the coming years. Who is vulnerable? What do the patterns say and why? Why are these patterns in place? These are important questions that we are just beginning to uncover.

I hope I have answered many of your questions. Any thoughts? Who agrees?

[MiamiensisWx]

Model links... notice the upcoming long-term potential pattern change consensus...

http://moe.met.fsu.edu/tcgengifs/

[CHRISTY]

capeverdewave from everything ive heard to this point to me seems to indicate that 2006 will be very much alike to 2004 and 2005 i really dont see a reason why the strong bermuda high that was around last year wont be around in 2006.dry conditions to me dont tell what a hurricane season might look like.as far as models form what i know there no model that can predict what is going to happen so far in the so far in the future.

[Scorpion]

Wow, extremely professional. Your knowledge is pretty extensive on this subject.

[KWT]

To be honest La Nina is now so weak I'd be tempted to say the condtions are closer to nuetral rather then La Nina in the Pacific at the moment.

So I'd think for the hurricane season it'd be far better to use years that have had nuetral condtions rather then La Nina because I can't see La Nina lasting much longer.

[MiamiensisWx]

Actually, the La Nina could make a brief surge back. I expect some cooler anomaly Pacific SSTs to blossom, especially since most of the warmer SSTs in the eastern and central Pacific are partly related to the surface, rather than the subsurface. Surface SST anomalies can change in a millisecond, practically. However, I agree that is the forecast pattern change can - and may very well - switch back to previous ridging central/west-central Atlantic by August/September. Depends on how the patterns shape up.

[Scorpion]

On this subject, I disagree. I expect a slightly positive neutral season, with El Nino showing its ugly face in October.

[CHRISTY]

My advise to everyone is to be prepared come june 1 and with the thought in mind that might see a very active season in 2006 with not as many storms but with huge affects on the U.S..(REMEMBER IT ONLY TAKES ONE!ANDREW IS A PRIME EXAMPLE OF THAT IT WAS A SLOW SEASON BUT IT ALMOST ENDED UP COSTING ME MY LIFE.)

[terstorm1012]

CapeVerde...I'm thinking something closer to 1999 as an analog.

1999 was extremely dry here and our drought wasn't broken until Dennis/Floyd came through.

1996 was a wet year. It rained the entire spring and summer as I recall. July 1996's Bertha helped that wet cycle along as well, along with the wickedly wet winter of '95-96.

Right now it's fairly dry up here and we just had a statewide drought watch declared. The pattern could change to a more wet spring and summer but we cycle between these wet and dry cycles here every 3-5 years or so, and our last drought cycle ended in 2002. (2003 ended up being pretty wet, and then we had Isabel.)

[Weatherfreak000]

I disagree with that.

Mostly the broken logic around that because of La Nina we're DEFINITELY gonna see increased Cape Verde activity which is hardly true. It doesn't mean much of anything because I don't see anything that points to that.


And even if conditions are good for an active CV Season it doesn't mean it's gonna happen because storms don't follow a blueprint. Vince is a prime example of that. So to put it blunt, I find that Cape Verde Seasons are LUCK based.


1. Does shear happen to have been in the area at the time?

2. Is dry air present at the time?

3. Will these conditions persist long enough to stop development?



It just so happened 05 had that, it's not it couldn't have been a CV year Irene was a CV storm it's all about the conditions affecting the waves at a certain time.

[HurricaneHunter914]

True, it depends on the conditions at that time. Like Katrina, if she formed in November she wouldn't have been the most well known monster it is today.

[Weatherfreak000]

We simply don't have even solid evidence to support La Nina comparing to recurve years. Two or three examples isn't worth anything.

[CHRISTY]

We simply don't have even solid evidence to support La Nina comparing to recurve years. Two or three examples isn't worth anything.

very good point 2 or 3 years doesnt equal to a specific pattern...

[MiamiensisWx]

What about 1998, 1950, and 1955? Those were La Nina years and had lots of recurves. Also, where the storms form has a lot to do with it, too. La Nina supports Cape Verde-type storms further east, while the patterns supporting recurvature/Carolina hits tend to be in place in many La Nin a years. I am NOT saying the La Nina ITSELF results in recurves and Carolina hits; I am saying the tending dominant patterns in many La Nina years do.





These were all likely La Nina years. Look at the patterns. They also support my idea of the western Gulf being at risk in many La Nina years. While this is all far from a given, a general pattern can be observed.

[MiamiensisWx]

Also, Florida is very vulnerable from the southwest during La Nina years. My point is that Florida tends to be hit less often from the east in several La Nina years.

[Weatherfreak000]

MOST LIKELY La Nina years.


I sincerely doubt in 1950 we knew the exact conditions for La Nina years CapeVerde, also let's not forget regardless that's still only three years of data from 55 years.


That's not sufficient data to find a pattern.

[MiamiensisWx]

We are not positive they were La Nina years, true; however, I think you CAN find a pattern somewhat.

[Weatherfreak000]

We are not positive they were La Nina years, true; however, I think you CAN find a pattern somewhat.

I disagree, there is no pattern.


If there were surely mets would associate La Nina with recurvature and I don't see that.

[benny]

I have noticed some tendency for la nina years to have a strong meridional component-type track to them (N-S).... however without a full study nothing definitive can be said. You would have to compare contrast the la nina years with the el nino years as a whole.. not just a selective sample. Tendencies are not exactly the same thing as realities though... if the signal is strong enough, you should be able to find it in composite or correlation work. I do know what you mean, we have had some ferocious la nina events that have been evil for the e coast but exactly why is still a mystery...

[CHRISTY]

it will come to were the bermuda high sets up this year and i think nobody can tell u forsure were it might set up.thats why iam really looking forward to NOAA's update and especially bill grays because i would like to more about what kind of pattern might be setting up and who will be more at risk.but again these are only predictions nobody truly knows whats gonna happen.still as the years go by iam sure they will only get better in predicting these patterns.