Modiki El Niños and Atlantic hurricane activity

By: Dr. Jeff Masters , 1:48 PM GMT on July 08, 2009

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It's an El Niño year, which typically means that Atlantic hurricane activity will be reduced. But not all El Niño events are created equal when it comes to their impact on Atlantic hurricane activity. Over the past 150 years, hurricane damage has averaged $800 million/year in El Niño years and double that during La Niña years. The abnormal warming of the equatorial Eastern Pacific ocean waters in most El Niño events creates an atmospheric circulation pattern that brings strong upper-level winds over the Atlantic, creating high wind shear conditions unfavorable for hurricanes. Yet some El Niño years, like 2004, don't fit this pattern. Residents of Florida and the Gulf Coast will not soon forget the four major hurricanes that pounded them in 2004--Ivan, Frances, Jeanne, and Charley. Overall, the 15 named storms, 9 hurricanes, and 6 intense hurricanes of the hyperactive hurricane season of 2004 killed over 3000 people--mostly in Haiti, thanks to Hurricane Jeanne--and did $40 billion in damage.

A new paper published in Science last Friday attempts to explain why some El Niño years see high Atlantic hurricane activity. "Impact of Shifting Patterns of Pacific Ocean Warming on North Atlantic Tropical Cyclones", by Georgia Tech researchers Hye-Mi Kim, Peter Webster, and Judith Curry, theorizes that Atlantic hurricane activity is sensitive to exactly where in the Pacific Ocean El Niño warming occurs. If the warming occurs primarily in the Eastern Pacific, near the coast of South America, the resulting atmospheric circulation pattern creates very high wind shear over the tropical Atlantic, resulting in fewer hurricanes. This pattern, called the Eastern Pacific Warming (EPW) pattern, occurred most recently during the El Niño years of 1997, 1987, and 1982 (Figure 1). In contrast, more warming occurred in the Central Pacific during the El Niño years of 2004, 2002, 1994, and 1991. The scientists showed that these Central Pacific Warming (CPW) years had lower wind shear over the Atlantic, and thus featured higher hurricane activity than is typical for an El Niño year. One of the paper's authors, Professor Peter J. Webster, said the variant Central Pacific Warming (CPW) El Niño pattern was discovered in the 1980s by Japanese and Korean researchers, who dubbed it modiki El Niño. Modiki is the Japanese word for "similar, but different".


Figure 1. Difference of Sea Surface Temperature (SST) from average during the peak of hurricane season, August-September-October, for seven years that had El Niño events (except for 2009, when the SST anomaly for July 1 - 3 is plotted). On the left side are years when the El Niño warming primarily occurred in the Eastern Pacific (EPW years). On the right are years when the warming primarily occurred in the Central Pacific (CPW years). Shown on the top of each plot is the number of named storms (NS), hurricanes (H), and intense hurricanes (IH) that occurred in the Atlantic each year. Atlantic hurricane activity tends to be more prevalent in CPW years than EPW years. An average hurricane season has 10 named storms, 6 hurricanes, and 2 intense hurricanes. Image credit: NOAA/ESRL.

What, then, can we expect the current developing El Niño event to do to 2009 hurricane activity? Kim et al. note that in recent decades, the incidence of modiki CPW El Niño years has been increasing, relative to EPW years. However, the preliminary pattern of SST anomalies in the Pacific observed so far in July (lower left image in Figure 1) shows an EPW pattern--more warming in the Eastern Pacific than the Central Pacific. If Kim et al.'s theory holds true, this EPW pattern should lead to an Atlantic hurricane season with activity lower than the average 10 named storms, 6 hurricanes, and 2 intense hurricanes. There is still a possibility that the observed warming pattern could shift to the Central Pacific during the peak portion of hurricane season, however. We are still in the early stages of this El Niño, and it is unclear how it will evolve.

Jeff Masters

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The computer models are taking invest 95 all the way to cat 2 with 96 mph
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Quoting tornadofan:
1080 hr forecast???

Anyone got a 1000 day forecast instead? LOL.

Just having fun with ya...


Any body got a year 3000 forecast.
Member Since: October 28, 2006 Posts: 57 Comments: 29714
Quoting tornadofan:
1080 hr forecast???

Anyone got a 1000 day forecast instead? LOL.

Just having fun with ya...


LOL LOL....Here ya go!!, actually it is 1008 hours out...lol. Link
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looks like 95E is well under way on being TD 4E
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I have a model question :)

Can anyone point out one instance where any model actually got anything right more than a day out this entire year so far ?
Member Since: June 12, 2005 Posts: 6 Comments: 8183
1080 hr forecast???

Anyone got a 1000 day forecast instead? LOL.

Just having fun with ya...
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Quoting Drakoen:
And that's why people shouldn't have access to the CFS.


Obviously, I'm not taking the model output seriously, having fun looking WAY out into the future....kind of like the 384 hr GFS model. Next time I'll put a LOL at the end of the link.
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Quoting Drakoen:
And that's why people shouldn't have access to the CFS.


lol
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sorry, meant Gulf...
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And that's why people shouldn't have access to the CFS.
Member Since: October 28, 2006 Posts: 57 Comments: 29714
Any long range models still showing activity in gulf? I know there is something supposedly that "might" get into the guld and maybe do and ike track thing...anything to that still?
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Southeast Weather Blog
Member Since: October 28, 2006 Posts: 57 Comments: 29714
Hmmm....the 1080 hour CFS model forecast. Take this with a TON of salt!! Link
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'El Nino' arrives in Pacific for a months-long stay


Link

El Nino conditions return to affect U.S. weather


Link

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Quoting hurricane23:


300hr+ hmm dont think it will happen lol.


lol true
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Quoting IKE:


30-50?



looks like 5-20 to me :/
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Quoting Acemmett90:
456
its doing this in 30-50kt shear thats is what is surprising me


Waves can and do produce convection in the face of vertical shear (diffluence) which is not related to cyclogenesis. However, I am watching this one. But currently I would not say its looking good.
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671. IKE
Quoting Acemmett90:
456
its doing this in 30-50kt shear thats is what is surprising me


30-50?

Member Since: June 9, 2005 Posts: 23 Comments: 37858
I really don't put to much stock in long range forecasts for hurricanes; except for the El Nino factor.If I had to make an entry in a long range forecast betting pool, I would go with an average to slightly below; with the season basically normal until late Sept, early Oct, where it might just end early.

But if the season only had 6 storms, it would not surprise me.And if the season had 13 storms, that would not surprise me either.

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Quoting BenBIogger:
CFS July 20



300hr+ hmm dont think it will happen lol.
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Quoting GBguy88:



Any chance it could make it far enough west as to affect Hawaii?


i really doubt it, its too far south, and if it
does get picked up to the north dry air would kill it



to find 95 E, look at the very bottom tip
of the baja peninsula on mexico, and then follow the line downwards..

another thing to note is that the whole state of hawaii is under 60 knots of wind shear.. even if it does make it to hawaii it wont be anything more than a thunderstorm imo. ask the expert for back up bc i could be wrong
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.
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The wave is producing disorganize clusters of convection. Organization invovles symmetry, sync and curvature and not just deep convection. Compare that wave to the pre-cursors of some tropical cyclones and you'll notice the difference.
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CFS July 20

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Quoting Acemmett90:
Imagine how this wave would look with no shear


it would prob be developing...:)
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Had a chance to view surface pressures on the ECM long range earlier this morning and they are unreal,no what you wanna see if you enjoy viewing tropical cyclones.Hopefully we'll get some interesting storms to track though.
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Quoting nrtiwlnvragn:
12Z ECMWF low in gulf long term (192hrs). See if it holds it in the next couple of runs.


Good evening...

Interesting... since this is a similar scenario I showed last night on the CFS output for 22+HR where a frontal area becomes the focus for development for a low to develop late next week. I guess the CFS wasn't the only model pulling my leg. Indeed if ECMWF persists and other models join in then thing will get interesting.
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Quoting 2010hurricane:
I wonder what will be the amount of storms in 2010?


Most likely abaove average since it will plus Nino year. years directly after and before ENSO events are active.
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Quoting HurricaneSwirl:
i think we'll be looking at hurricane carlos over the next couple of days. invest 95E looks REALLY good, and its a bit farther south and east
of blanca, giving it more hot water and more time
before it hits dry air.



Any chance it could make it far enough west as to affect Hawaii?
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Quoting BenBIogger:
4 named storms
1 hurricane
0 major hurricane

sound reasonable


One thing is for sure 2009 should be an interesting season.
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Thats some massive convections around 57w...wowee!

Yes yes I know there is shear in the central carrib
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4 named storms
1 hurricane
0 major hurricane

sound reasonable
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652. IKE
Quoting nrtiwlnvragn:


None that I've seen, not even ensemble members.


Yeah...I don't see any either...yet....
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Not like it is be all end all of Ninos.

Member Since: August 16, 2007 Posts: 6 Comments: 12461
Quoting IKE:


I knew someone would have already posted that.

Interesting run. Any model support?


None that I've seen, not even ensemble members.
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Quoting jrweatherman:
Nasty shear right now over the central caribbean.


With a nino officially established i dont see anything developing till mid/early august.Strong westerlies all across the area.

With a nino in place, wouldn't the westerlies remain across that area?


The 1016 mb line is forecast to be almost to Trinidad in a couple of weeks, which is quite high; BUT it is where the 1016 line sets up once early August comes that is more important.Surface pressures are quite high in many areas across the basin with a cool pocket of sst's across the main development region.
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i think we'll be looking at hurricane carlos over the next couple of days. invest 95E looks REALLY good, and its a bit farther south and east
of blanca, giving it more hot water and more time
before it hits dry air.
Member Since: Posts: Comments:
Nasty shear right now over the central caribbean.


With a nino officially established i dont see anything developing till mid/early august.Strong westerlies all across the area.

With a nino in place, wouldn't the westerlies remain across that area?
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644. IKE
Quoting nrtiwlnvragn:
12Z ECMWF low in gulf long term (192hrs). See if it holds it in the next couple of runs.


I knew someone would have already posted that.

Interesting run. Any model support?
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting jeffs713:
Nasty shear right now over the central caribbean.


With a nino officially established i dont see anything developing till mid/early august.Strong westerlies all across the area.

What king of impact will this nino event will have on this season is yet to be seen.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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