About Jeff Masters
Cat 6 lead authors: WU cofounder Dr. Jeff Masters (right), who flew w/NOAA Hurricane Hunters 1986-1990, & WU meteorologist Bob Henson, @bhensonweather
Modiki El Niños and Atlantic hurricane activity
By: Dr. Jeff Masters , 1:48 PM GMT on July 08, 2009
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
The views of the author are his/her own and do not necessarily represent the position of The Weather Company or its parent, IBM.
Reader Comments
Category 6™
190. BobinTampa
188. sky1989
Betsy-1965 a year which only featured 5 or 6 storms, Betsy was the costliest hurricane at the time
Agnes-1972 a year which featured 7 storms, Agnes surpassed Betsy as the costliest U.S. hurricane
Alicia-1983 a year which featured only 4 named storms, devastated Galveston and Houston and was one of the costliest hurricanes at the time
Andrew-1992 a year which featured only 6 tropical storms, shattered Hugo's record as the costliest U.S hurricane (at the time) and still remains the second costliest storm behind Katrina.
I'm sure there are many more that I am forgetting right now, but I hope everyone can see the point.
Be prepared every year because no one can determine, for sure in advance precisely what will happen.
187. Weather456
I don't think it will be tropical. But it won't be frontal. it could end up being a barotropically cold or hyprid system, not sure right now.
186. weathermanwannabe
185. Weather456
Thank you
184. Patrap
getagameplan.org
183. Patrap
182. SomeRandomTexan
181. tropicfreak
LOL
180. sporteguy03
I agree, just hope the lurkers who read the blog daily realize that "numbers" are great on paper and in theory until they effect you, stay prepared and alert.
179. Skyepony (Mod)
The 2009 wildfire season roared to life in Alaska on 02 July - 03 July 2009, with a number of very large and very intense fires breaking out across interior portions of the state. A ridge of high pressure was in place over the region, allowing Fairbanks to experience a high temperature above 80º F (27º C) on both days. GOES-11 visible images (above) showed some impressive smoke plumes developing on 02 July, especially from the fire located to the east-southeast of Fort Yukon (station identifier PFYU) — note the pulses of “pyrocumulus” that emanated from this >19,000 acre “Little Black One” fire complex:
178. KEEPEROFTHEGATE (Mod)
177. PanhandleChuck
175. AllStar17
So, 456 -- Any subtropical or tropical development with that system off the Carolinas?
174. SomeRandomTexan
172. CaneWarning
I know. You are actually one of my favorite posters in here.
169. CaneWarning
Well then they need to take the quote option away.
165. Seastep
I know where you are coming from, but to correct the record for any lurkers that may take you at face value and be misinformed, shear is only 5-20 over the entire gulf and dropping. That is not high.
164. Skyepony (Mod)
I said it 3 days ago, including the mention off GA. Don't really expect anything too exciting the next few days though even. When it shifts again, the last low may ride the gulf stream north instead of just north of Bermuda like the ones before it. That could get interesting.
I still give the Caribbean blob a chance of a moments glance of a swirl in the BOC like the last two waves.
Sea breeze is fired up here..decent winds, a white out of rain & the lightning is scaring the kids.
163. CybrTeddy
Defeats the purpose of ignore if you quote him. :p
162. CaneWarning
Thank you so much for this update...
161. SomeRandomTexan
160. Patrap
Ignore means that,..ignore.
159. SomeRandomTexan
158. CybrTeddy
""""67. stormkat 9:40 AM CDT on July 08, 2008 Hide this comment.
i told you guys last thursday bertha was going to be a fish storm..i told you the strong trough off the east coast would cause a major weakness in the high and bertha would pass 200 miles to the east of bermuda...well jw what
happen to the storm that you said was going to
develop in the leeward islands...thats the
reason why i do my own forecasting i dont need
these computers...you guys think they are gospel..if you continue to follow them you will very seldom be right in a forecast...jw it looks like you really bombed on that one but like i said we all makes mistakes..i was right on with bertha and my forecast for the rest of the month is no tropical storms the shear has kicked in all over...guys like i said all along the famous dr gray blew it again this year and he will have to revise his forecast from 15 named storms to 7 if he gets that many...the dust is starting to develop on the coast of africa so that could kill anything from developing ...my latest data shows the tropics to be very quiet for july unless a cold front heads into the GOM then we will have to watch it closely...but thats not expected to happen guys...i will keep you informed and ill be back in 3 weeks unless something develops in the GOM...if you guys would like to email me feel free to do so...i will answer any questions you might have...im here to help you...stormkat""""
Sad, just ignore him.
157. Patrap
TDWR High Definition Radar
New Orleans, Velocity Azimuth Display Wind Profile Range 124 NMI
Microbursts and Straight Line Winds in that Line.
155. Patrap
New Orleans, Base Reflectivity 0.20 Degree Elevation Range 48 NM
154. CybrTeddy
Isabel was a real bad experiance. Had more storm surge than Ike.
153. SomeRandomTexan
SSTs in the tropical atlantic may be normal or below but I guess he sure didn't look at the GOM or areas around Florida those are 1-2 degrees above
152. SpicyAngel1072
same "virus" ?
151. hcubed
Good lord, he's back...
150. Orcasystems
Its one of my AOI's :)
149. pearlandaggie
of course, the rebuttal comes before the report is officially published...but, OF COURSE, the surface temperature record is *accurate*
147. tropicfreak
21N87W ALONG 14N89W AND INTO THE E PACIFIC MOVING W NEAR 18 KT.
THIS WAVE COINCIDES WITH A SIGNIFICANT AREA OF INCREASED
PRECIPITABLE WATER ACROSS THE WRN CARIBBEAN AND CENTRAL AMERICA.
INTERACTING WITH A DIFFLUENT ATMOSPHERE ALOFT...SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS FOUND ACROSS THE WRN
CARIBBEAN AND PORTIONS CENTRAL AMERICA FROM 14N-19N BETWEEN
82W-90W.
CARIBBEAN SEA...
A TROPICAL WAVE IS TRACKING WWD ACROSS THE ERN YUCATAN PENINSULA
AND CENTRAL AMERICA CONTINUING TO IMPACT THE NW CARIBBEAN WATERS
AND PORTIONS OF CENTRAL AMERICA. THE WAVE CONTINUES TO MOVE
BENEATH AN UPPER LEVEL ANTICYCLONE CENTERED OVER WRN GUATEMALA
NEAR 15N92W AND THE INTERACTION BETWEEN THESE TWO FEATURES IS
GENERATING SCATTERED SHOWERS AND TSTMS FROM 14N-19N BETWEEN
82W-90W...INCLUDING PORTIONS OF HONDURAS...BELIZE AND GUATEMALA.
ALSO SCATTERED SHOWERS AND TSTMS ARE ACROSS THE SW CARIBBEAN AND
FAR ERN COASTAL AREAS OF WRN PANAMA...COSTA RICA AND SE
NICARAGUA FROM 8N-13N W OF 80W. SURFACE CONVERGENCE DUE TO THE
PROXIMITY OF THE E PACIFIC ITCZ ALONG 8N IS ENHANCING THIS
ACTIVITY. THE REMAINDER OF THE CARIBBEAN...WITH THE EXCEPTION OF
THE FAR NERN WATERS...IS UNDER THE INFLUENCE OF A SAHARAN AIR
LAYER OF DUST SUSPENDED IN THE MIDDLE LEVELS OF THE ATMOSPHERE.
THE SUSPENDED DUST IS OBSERVED ON VISIBLE SATELLITE IMAGERY AND
NUMEROUS OF THE UPPER AIR TIME SECTION ANALYSES ACROSS THE ERN
AND CENTRAL CARIBBEAN. WITH THIS DRIER AIR IN PLACE...ONLY A FEW
ISOLATED LOW-LEVEL SHOWERS ARE NOTED N OF 16N E OF 67W IN
ASSOCIATION WITH A SURFACE TROUGH THAT EXTENDS FROM THE CENTRAL
ATLC TO NEAR MONTSERRAT. FRESH TO STRONG ELY TRADE WIND FLOW
CONTINUES ACROSS THE BASIN AND IS FORECAST TO PERSIST THROUGH
FRIDAY AND INTO THE WEEKEND.
From the 205 NHC discussion.
146. weathersp
Non-frontal but still baroclinic, not Barotropic.
145. ClearwaterSteve
144. TexasHurricane
143. presslord
Good...shut it down...it's just depressing, anyway...