Modiki El Niños and Atlantic hurricane activity
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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Why do you say that?
Tropical Depression "GORIO" has slightly accelerated and is now crossing the Babuyan Group Of Islands.
Tropical Cyclone Bulletin #3
========================
At 5:00 AM PhST, Tropical Depression Gorio (05W) located at 19.3ºN 121.0ºE or in the vicinity of Calayan Island has 10 minute sustained winds of 55 km/h (30 knots).
Signal Warnings
=================
Signal Warning #1 (30-60 kph winds)
Luzon Region
1.Cagayan
2.Calayan group of Islands
3.Babuyan group of Islands
4.Kalinga
5.Apayao
6.Abra
7.Ilocos Sur
8.Ilocos Norte
9.Batanes
Additional Information
=======================
Public Storm Warning Signal elsewhere now lowered.
TD "GORIO" is expected to enhance the southwest monsoon and bring rains over the western section of Luzon and Western Visayas.
Residents in low lying areas and near mountain slopes are advised to take all the necessary precautions against possible flashfloods and landslides.
The public and the disaster coordinating councils concerned are advised to take appropriate actions and watch for the next bulletin to be issued at 11 AM today.
2004 type season will not happen
Jim Cantore busting out the door like a boxer going into the ring with his poncho and microphone....Lol
Just another troll.......ignore.
Troll city today on this blog.
I agree.
2004 had more than 6 Storms. lol
A fast system must be late for some appointment. =P
the next advisory at 3:00 am may be the last advisory, LOL
True, radar would be helpful right about now,i think were going to get a pretty nasty squall line within 2 hours.
how many of us has lost the game, already?
LOUDER!!!!!!!!!
I know who you are...hey stormtop.
maybe this is the year that the Atlantic hurricane season starts in August.
no BeBIogger should be a troll. I wouldn't count off the season. It's only july people. Show some patience. I know it's hard to be patient but the time will come. We're what? not even a quarter of a way through the season. And you guys are already impatient. Just wait, perhaps come august this blog will be an anthill. The time will come, just show some patience.
Wise
:)
Possible... lol
think about that
LOL, no ones wants that. For some is either now or never. Impatience is growing each and every day and leading to some of the most ridiculous speculations. July 10 is 2mr which is the average date of the 1st named storm. By Monday ppl will be leaving for good with one or 2 left by the end of the month.
July makes me 4 years here, been here since the blogs started. This is the first year I have seen this on the blog. Interestingly, this is the first time on the blogs the season started so late. People's perception of a normal hurricane season have been damaged severely by recent years.
what is suppose to be in the gulf? going where?
Pacific East - 4 cyclones
Atlantic - 1 cyclone
India - 3 cyclones (2 named)
Pacific West (JMA) - 4 cyclones, (JTWC) - 5 cyclones, (PAGASA) - 7 cyclones
September 14th, that happened in the slowest season on record, 1914
Would not be surprised to see a storm like Debby (2006) form, where it forms then weakens, although it won't move as far north as Debby did.
Nope, not on WU :)
StSimonsIslandGAGuy,12,7,3,0,7-12
no there were no hurricanes that year, just 1 TS
Just needs to be watched, nothin serious, need more model support of course.
Yea but then in 1915...
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