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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Nuttin' but hot weather up here.
Basseterre, SK
lol, Climate change is a very delicate subject that I think no one can cover all angles. It is strongly debated with little agreement.
Great Graphic.......Well Folks, speaking of the kids, time to get them ready for bed. Have a great night folks....WW
Except in this month's Discover mag. Poorly covered on one side only. ("Quick, we need to publish something now that drives the US Senate to pass the bill. Let us just get these few known proponents to answer some friendly questions...no tough ones! Yes sir.")
Canceling my subscription today.
Bluest sky i've seen in a while,too much dust lately,that normal though.
Awesome shot.
Thanks, but the credit really belongs to Landsea. He beat down many hurricane historical myths concerning comparing seasons of the distant past to recent times in a 4-page Eos paper while everyone else writes 40 pages in BAMS extolling how AGW made the TC numbers go up.
The real source is here: http://www.aoml.noaa.gov/hrd/Landsea/landsea-eos-may012007.pdf
I especially enjoy the first part of Figure 3 that shows all of the measurements during an average day in 1907 and 2007. Astounding that we try to depend on any wind/pressure intensities from back then for anything.
I highly recommend the read.
TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
222 PM EDT THU JUL 09 2009
DISCUSSION FROM JUL 09/0000 UTC. A BROAD MID/UPPER LEVEL RIDGE
REMAINS OVER THE WESTERN-CENTRAL USA AND NORTHERN STATES OF
MEXICO. THROUGH 48-72 HRS THE RIDGE WILL EXPAND TO THE MID
ATLANTIC REGION IN THE EASTERN USA. A TROUGH BOUNDS THE EASTERN
PERIPHERY OF THIS RIDGE...WITH AXIS SOUTH INTO THE EASTERN GULF OF
MEXICO. THE BROAD RIDGE IS DIVERTING SHORT WAVE ENERGY SOUTHWARD
INTO THE BASE OF THIS TROUGH. THIS WILL FAVOR FORMATION OF A
CLOSED LOW OVER THE NORTHEAST GULF OF MEXICO BY 30-36 HRS. BY 48
HRS THE LOW WILL CENTER NEAR 25N 85W...WHILE THE TROUGH EXTENDS
INTO THE NORTHERN YUCATAN/WESTERN CUBA. UNDER INFLUENCE OF THE
RIDGE...THE LOW WILL RETROGRESS TO THE SOUTHWEST TO JUST NORTH OF
THE YUCATAN BY 72-78 HRS...
Link
Adrian
GOM 60 Hour Wave Forecast (using WaveWatch 3)
GOM 60 Hour Surface Current Forecast,Loop Current included,area specific
AOI
AOI
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
500 PM PDT THU JUL 9 2009
FOR THE EASTERN NORTH PACIFIC...EAST OF 140 DEGREES WEST LONGITUDE..
SHOWERS AND THUNDERSTORMS ASSOCIATED WITH AN AREA OF DISTURBED
WEATHER LOCATED ABOUT 900 MILES SOUTH OF THE SOUTHERN TIP OF BAJA
CALIFORNIA CONTINUE TO SHOW SIGNS OF ORGANIZATION. CONDITIONS
APPEAR TO BE FAVORABLE FOR THIS SYSTEM TO BECOME A TROPICAL
DEPRESSION TONIGHT OR FRIDAY AS IT MOVES WEST-NORTHWESTWARD AT 10
TO 15 MPH. THERE IS A HIGH CHANCE...GREATER THAN 50 PERCENT...OF
THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.
THE REMNANTS OF BLANCA...ACCOMPANIED BY A FEW SHOWERS...ARE CENTERED
ABOUT 900 MILES WEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA.
ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
$$
FORECASTER PASCH
95E development up to high now
Maybe it did, maybe it didn't. If it did, it was likely NE of there at that time.
(If ya read that QuikScat paper, you'll know why I say these things.)
Is Landsee implying that because we didn't have satellites there was a big gap in the Atlantic data incapable of registering cyclones? Previous years would suggest otherwise. Storms were detected in that region.
1926
http://en.wikipedia.org/wiki/File:1926_Atlantic_hurricane_season_map.png
1929
http://en.wikipedia.org/wiki/File:1929_Atlantic_hurricane_season_map.png
1932
http://en.wikipedia.org/wiki/File:1934_Atlantic_hurricane_season_map.png
1934
http://en.wikipedia.org/wiki/File:1934_Atlantic_hurricane_season_map.png
Finally, no need for satellites to tell you that 2005 was incredibly unusual, if not unprecedented, when you have a storm like Vince
http://en.wikipedia.org/wiki/Hurricane_Vince_(2005)
OK, but that is over complicating a simple observation, something I intend not to do. I've also read details on QuikSCAT imagery.
Stay safe everyone. My thoughts are with you ALL!
NASA developing ocean storm model
By Thomas A. Horne
NASA announced that it will combine satellite imagery with computer models and artificial intelligence to come up with a system that will be able to warn ocean-going pilots of dangerous thunderstorm-related turbulence. The National Center for Atmospheric Research (NCAR) in Boulder, Colo., is a partner in the project.
True, so true.
It appears as though the heat is not as concentrated as it was in the Gulf of Mexico, but rather, it has spread out, so that most of the Gulf has some, albeit small, degree of oceanic heat content.
The east coast, however, appears much warmer.
Incapable? Of course not. But just because storms in those years ulimately made landfall or were stumbled upon by a ship doesn't mean all were measured.
Go look at the full paper at the link I posted. He shows the obs for an average day in 1907, shows how the percent of TCs making landfall has dropped as remote sensing has improved and coastal populations have grown. And more. Really shows the effect of improved observations and the likelyhood that we missed many.
And, do you propose that it is impossible that a season like 2005 couldn't occur every 70 years or so? All of the factors that made that one what it was surely have happened before and will again...hopefully not anytime soon.
what is that???probably extratropical
94L, look at the time stamp, July 6 2009, or Monday
Something seems wrong there, the ENSO says temps are above average across the gulf.
They are.
Dennis!
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