La Niña by July?

By: Dr. Jeff Masters , 1:42 PM GMT on June 08, 2010

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El Niño rapidly dissipated in May, and we are now very close to entering into a La Niña event, according to the latest sea surface temperature (SST) data over the tropical Eastern Pacific. The weekly SST readings in the area 5°N - 5°S, 120°W - 170°W, also called the "Niña 3.4 region", fell to 0.4°C below average on June 7, a full 1°C drop in just one and a half months. This puts us very close to the -0.5°C threshold needed to be considered a La Niña event, according to NOAA's latest El Niño Discussion. The Australian Bureau of Meteorology showed conditions in the Niña 3.4 region were not quite that cool--0.2°C below average for the week ending June 6. Nevertheless, the speed of the collapse of El Niño makes it likely that a La Niña event is on its way this summer, and NOAA's Climate Prediction Center has issued a La Niña watch. Ten of the 23 El Niño models (updated as of May 19) are predicting La Niña conditions for hurricane season. However, as NOAA's Climate Prediction Center commented in their June 3 advisory, a number of the more reliable models are now calling for La Niña to develop this summer. They comment, "there is an increasing confidence in these colder model forecasts, which is supported by recent observations that show cooling trends in the Pacific Ocean and signs of coupling with the atmospheric circulation." Historically, about 35 - 40% of El Niño events are followed by a La Niña within the same year.


Figure 1. Atlantic named storm, hurricane, and intense hurricane activity since the active hurricane period we are in began in 1995. Both La Niña and neutral years have shown similar levels of Atlantic hurricane activity, though the figures are somewhat skewed by the record-setting year of 2005. Background photo: Hurricane Dean, taken from the Space Shuttle.

It is interesting to note that the last time we had a strong El Niño event, in 1998, El Niño collapsed dramatically in May, and a strong La Niña event developed by hurricane season. History appears to be repeating itself, and I predict the emergence of La Niña by July. Since La Niña events tend to bring lower amounts of wind shear to the tropical Atlantic, we can expect a much more active Atlantic hurricane season than usual in 2010. Since 2010 is similar to 1998 in the behavior of the El Niño/La Niña cycle, it is possible that this year's hurricane season could resemble the 1998 Atlantic hurricane season. That year had about 40% above-average activity, with 14 named storms, 10 hurricanes, and 3 intense hurricanes. The season was relatively late-starting, with only one named storm occurring before August 20. Once the season got going, six named storms affected the Gulf of Mexico, including two hurricanes, Earl and Georges, that passed directly over the location of the Deepwater Horizon oil spill.


Figure 2. Tracks of all named storms for the 1998 Atlantic hurricane season.


Figure 3. Typical regional weather anomalies observed during June - August when La Niña conditions are present. The Caribbean tends to be cloudier and wetter than average, but there is typically little change to temperature and precipitations patterns over North America. Image credit: NOAA Climate Prediction Center.

Oil spill update
Light east, southeast, or south winds of 5 - 15 knots will blow today through Saturday, according to the latest marine forecast from NOAA. These winds will keep oil near the beaches of Alabama, Mississippi, and the extreme western Florida Panhandle, according to the latest trajectory forecasts from NOAA and the State of Louisiana. The latest ocean current forecasts from the NOAA HYCOM model are not predicting eastward-moving ocean currents along the Florida Panhandle coast this week, and it is unlikely that surface oil will affect areas of Florida east of Fort Walton Beach. Long range surface wind forecasts from the GFS model for the period 8 - 14 days from now show a southeasterly wind regime, which would prevent any further progress of the oil eastwards along the Florida Panhandle, and would tend to bring significant amounts of oil back to the shores of eastern Louisiana next week. If you spot oil, send in your report to http://www.gulfcoastspill.com/, whose mission is to help the Gulf Coast recovery by creating a daily record of the oil spill.


Figure 4. The oil spill on June 6, 2010 at 8:32pm EDT, as seen by Synthetic Aperture Radar (SAR) imagery from the Italian Cosmo-SkyMed (COnstellation of small Satellites for Mediterranean basin Observation) satellite. A large region of oil was a few miles offshore of Pensacola, Florida. Image credit: University of Miami Center for Southeastern Tropical Advanced Remote Sensing, Rosenstiel School of Marine and Atmospheric Science.

Oil spill resources
My post, What a hurricane would do the Deepwater Horizon oil spill
NOAA's fact sheet on Hurricanes and the Oil Spill
My post on the Southwest Florida "Forbidden Zone" where surface oil will rarely go
My post on what oil might do to a hurricane
Oil trajectory forecasts from NOAA
Gulf Oil Blog from the UGA Department of Marine Sciences
Oil Spill Academic Task Force
University of South Florida Ocean Circulation Group oil spill forecasts
Synthetic Aperture Radar (SAR) imagery from the University of Miami

"Hurricane Haven" airing again this afternoon
The tropical Atlantic is quiet right now, with no models predicting tropical cyclone development over the next seven days. I'll talk about all this nothingness on my live Internet radio show, "Hurricane Haven", at 4pm EDT today. Listeners will be able to call in and ask questions. The call in number is 415-983-2634, or you can post a question in the comments area on Shaun Tanner's blog. Some topics I'll cover on the show:

1) What's going on in the tropics right now--is this typical?
2) New advancements in hurricane science presented at this month's AMS Conference on Hurricanes and Tropical Meteorology last month

Today's show, which will probably be just 1/2 hour, will be at http://www.wunderground.com/wxradio/wubroadcast.h tml. The show will be recorded and stored as a podcast, as last week's show was.

I may take a break from blogging Wednesday, as I've got some catching up to do on other duties.

Jeff Masters

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Quoting Levi32:


I'd like to know what you are seeing as a limiting factor though to bring the number all the way down to "average" (that's what 14 is during a warm AMO cycle).


Maybe its what I am not seeing that leads me to lean towards an average and that is that so far all the right ingredients seem to be falling in place for a very active season. It reminds me of preparing for exams. You reach a peak and if you don't sit the paper then you start to lose the optimum state of preparation.

I would be surprised if all the key imgredients we see out there lining up remained in place for months on end. I've seen conditions swing too quickly from one end of the spectrum to another to believe that all the stars will remain aligned come what may.
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1191. Levi32
Quoting kmanislander:


There is an element of truth to that but I do believe that we should largely ignore 2005 in setting the benchmark unless and until we see more years with numbers in excess of 20. The active phase we have been in has not gone through the 20 barrier for any of the ten neutral and La Nina years above except for 2005. 20 is in fact beyond the upper end of those years.




I agree. I think anything above 1995's count of 19 should be considered an extreme year, because that is what it is, whether 28 is the highest or not. We'll have to see if we bust 20 again or even a couple more times during this warm AMO cycle though, because the last time this happened from the 1930s through the early 1960s, we had no satellites and the storm counts per year were less during that warm AMO cycle.
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Quoting Levi32:


2005 was a warm PDO year. The PDO tried to go cold in 1998 but flattened out. This year looks to be the year it starts going cold for good for the next 3 decades for the next phase of its multidecadal cycle. This winter will be brutal.

The horseshoe-shaped area of cold SST anomalies along the west coast of North America is a signature of a cold PDO in the north pacific.



Alright, thanks. I think I have a better understanding.
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Quoting kmanislander:


There is an element of truth to that but I do believe that we should largely ignore 2005 in setting the benchmark unless and until we see more years with numbers in excess of 20. The active phase we have been in has not gone through the 20 barrier for any of the ten neutral and La Nina years above except for 2005. 20 is in fact beyond the upper end of those years.




I think you are both saying the same thing only differently.
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1188. KEEPEROFTHEGATE (Mod)
Quoting Greyelf:


Actually, I've been curious about that...how does one check a name to see if they've been banned? (Assuming they don't have their own member blog to view, that is.)
only way you can see if a user has been banned is if he or she has an blog an even then it would have to be a total blog ban to know sometimes individuals can be banned from users blogs but still access others and in special cases you can be given a total site ban and it can be assign a time limit or it can be indefinte
Member Since: July 15, 2006 Posts: 170 Comments: 53605
1187. Levi32
Quoting SevereHurricane:


You know Levi, I am looking back at 6/7/05 on the OSDPD SSTA Map and it looks to me like 2010 has jumped back on top SSTA wise. Are you seeing the same thing as me?


I'm seeing neck and neck in the MDR. We have 2005 beat so far in the Gulf of Mexico.
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1186. pottery
Good Evening all
Just had another nice shower. 1.3" for the day...so far.
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Quoting DestinJeff:
Trying to infer any statistical significance from the chart in the main posts is a fruitless effort I think. Simply not enough datapoints, and the ones you do have are not mutually exclusive of other atmospheric conditions in the given year.

I won't doubt the experts, and certainly respect the opinion of everyone here ... but trying to forecast with such heavy weight on one factor (ENSO) is really a flip of the coin.


I learned after the 2009 Saints Season that statistics don't mean everything. whodat!
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hello my fellow caymanian bloggers and hello to all hey it is about we got some rain what do you guys think? anyway any new updates on the tropics or any between 12 and now
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Quoting Levi32:


You see though, nothing is considered hyperactive now unless it's comparable with 2005. Before that, 1995 was hyperactive, and so was 1969. Anything above 16 is a huge deal in the Atlantic, and we're all used to high numbers now because of the warm AMO cycle for the past 15 years and that will continue for at least another 15.


There is an element of truth to that but I do believe that we should largely ignore 2005 in setting the benchmark unless and until we see more years with numbers in excess of 20. The active phase we have been in has not gone through the 20 barrier for any of the ten neutral and La Nina years above except for 2005. 20 is in fact beyond the upper end of those years.


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Quoting Levi32:


2005 was a warm PDO year. The PDO tried to go cold in 1998 but flattened out. This year looks to be the year it starts going cold for good for the next 3 decades for the next phase of its multidecadal cycle. This winter will be brutal.

The horseshoe-shaped area of cold SST anomalies along the west coast of North America is a signature of a cold PDO in the north pacific.



You know Levi, I am looking back at 6/7/05 on the OSDPD SSTA Map and it looks to me like 2010 has jumped back on top SSTA wise. Are you seeing the same thing as me?
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1180. Greyelf
Quoting ShenValleyFlyFish:


Been there. Done that. We need to make an I've been banded t-shirt with a crow on the front.


Here's a crow graphic for you to use. I can't take the time to make the whole graphic. Maybe they'll ban me for it. Heh...
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Link

"Several of these conditions are now present."
and they are expected to persist through the hurricane season because we anticipate they are linked in part to the tropical multi-decadal signal. These conditions include 1) weaker (i.e. anomalous westerly) trade winds in the lower atmosphere, anomalous easterly winds in the upper atmosphere, anticyclonic circulation (i.e. streamfunction) anomalies in the upper atmosphere in both hemispheres, and reduced vertical wind shear." NOAA (5/27/2010).

Member Since: July 11, 2006 Posts: 14 Comments: 11289
Quoting HurricaneSwirl:


When did the PDO go cold? Was 2005 a cold PDO year? How long do the cold/warm PDO periods last?

Sorry for all the questionz. TYVMIA


2005 was a warm PDO year. Thats one of the reasons why there is some uncertainty.
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1177. Levi32
Quoting HurricaneSwirl:


When did the PDO go cold? Was 2005 a cold PDO year? How long do the cold/warm PDO periods last?

Sorry for all the questionz. TYVMIA


2005 was a warm PDO year. The PDO tried to go cold in 1998 but flattened out. This year looks to be the year it starts going cold for good for the next 3 decades for the next phase of its multidecadal cycle. This winter will be brutal.

The horseshoe-shaped area of cold SST anomalies along the west coast of North America is a signature of a cold PDO in the north pacific.

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Quoting ShenValleyFlyFish:


Been there. Done that. We need to make an I've been banded t-shirt with a crow on the front.
I need a medium or large. I have been there too. LOL
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1175. KEEPEROFTHEGATE (Mod)
Quoting kmanislander:


We could reach or surpass 20 this year, only a fool would say never, but one point on a graph does not a trend make. If we see 4 years with ranges between 20 and 28 then the discussion becomes something else entirely.
maybe it will become a 5 year cycle 05 10 15 20
Member Since: July 15, 2006 Posts: 170 Comments: 53605
Quoting stormwatcherCI:
Nope. If he/she was banned they wouldn't be able to post. This is said from experience. LOL


Been there. Done that. We need to make an I've been banded t-shirt with a crow on the front.
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Quoting sarahjola:
the Caribbean is looking like it wants to do something. starting to get some cloud cover out there. lets see if any storms get fired up in the next few days. just for fun i say we'll be watching something in the Caribbean this weekend. what do you think?
no facts or scientific reason for my statement, just for sh%@s and giggles.

Some flares of convection. Outside chance of an invest.
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1172. Grothar
Quoting SevereHurricane:


My thinking exactly.


There can be more than one anomaly for different reasons. If something is deemed out of the norm based upon certain criteria, that does not preclude another anomaly based upon different criteria.
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Quoting KEEPEROFTHEGATE:

daytime temps around 26 to 31c which is like mid 80's
may get a afternoon summer thunderstorm
nights cool off into high teens or high 60's unless we are having a summer heat wave
then the humidex kicks in and you can have days in july where temps exceed 32c and humidex values are high 30c's low 40c's range normally about 20 or so days can be expected like this some in july most in august
Thank you. She is very excited about going there.
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Quoting Levi32:


The warm AMO will likely continue for another 15-20 years before going cold, following the multi-decadal cycle of the past century. This, coupled with the PDO now going cold, means a period of possibly even more activity on average than we have seen since 1995.


Awesome... I will be in college at a perfect time. I see lots of Hurricane Chasing in my near future.
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Quoting Levi32:


The warm AMO will likely continue for another 15-20 years before going cold, following the multi-decadal cycle of the past century. This, coupled with the PDO now going cold, means a period of possibly even more activity on average than we have seen since 1995.


When did the PDO go cold? Was 2005 a cold PDO year? How long do the cold/warm PDO periods last?

Sorry for all the questionz. TYVMIA
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the Caribbean is looking like it wants to do something. starting to get some cloud cover out there. lets see if any storms get fired up in the next few days. just for fun i say we'll be watching something in the Caribbean this weekend. what do you think?
no facts or scientific reason for my statement, just for sh%@s and giggles.
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1167. Ossqss
Quoting MiamiHurricanes09:
Why?


Hummm, SST's globally dropping, Neutral conditions moving, MJO moving through? You guys tell me. I am just absorbing and analyzing :)
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1166. KEEPEROFTHEGATE (Mod)
Quoting stormwatcherCI:
My daughter is planning a trip to Canada the end of July. Can someone tell we what the weather is like that time of year up there ?

daytime temps around 26 to 31c which is like mid 80's
may get a afternoon summer thunderstorm
nights cool off into high teens or high 60's unless we are having a summer heat wave
then the humidex kicks in and you can have days in july where temps exceed 32c and humidex values are high 30c's low 40c's range normally about 20 or so days can be expected like this some in july most in august
Member Since: July 15, 2006 Posts: 170 Comments: 53605
1165. Levi32
Quoting kmanislander:


We could reach or surpass 20 this year, only a fool would say never, but one point on a graph does not a trend make. If we see 4 years with ranges between 20 and 28 then the discussion becomes something else entirely.


I'd like to know what you are seeing as a limiting factor though to bring the number all the way down to "average" (that's what 14 is during a warm AMO cycle).
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1164. Levi32
Quoting HurricaneSwirl:


Well lets hope that doesn't happen. I thought we were supposed to be nearing the end of the active period already? Considering I was born on the year the active period started, I haven't really got to known it yet. (which is a good thing)


The warm AMO will likely continue for another 15-20 years before going cold, following the multi-decadal cycle of the past century. This, coupled with the PDO now going cold, means a period of possibly even more activity on average than we have seen since 1995.
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Quoting Levi32:


You see though, nothing is considered hyperactive now unless it's comparable with 2005. Before that, 1995 was hyperactive, and so was 1969. Anything above 16 is a huge deal in the Atlantic, and we're all used to high numbers now because of the warm AMO cycle for the past 15 years and that will continue for at least another 15.


Ha! You answered this for me before I could even post :P Thanks, Levi.
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Quoting Levi32:


Indeed. 2005 may not be considered such an anomaly if we happen to bust 20+ storms this year.


We could reach or surpass 20 this year, only a fool would say never, but one point on a graph does not a trend make. If we see 4 years with ranges between 20 and 28 then the discussion becomes something else entirely.
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Quoting Levi32:


Indeed. 2005 may not be considered such an anomaly if we happen to bust 20+ storms this year.


Well lets hope that doesn't happen. I thought we were supposed to be nearing the end of the active period already? Considering I was born on the year the active period started, I haven't really got to known it yet. (which is a good thing)
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1159. Levi32
Quoting kmanislander:


12-19 is the low to high but overall the numbers are not excessively high for any year if you exclude 2005. To me, that says don't expect hyperactivity just because we have La Nina on the horizon and high SST.

You are correct about the average. My numbers for this season are 14/7/4 or 5 posted from mid May.



You see though, nothing is considered hyperactive now unless it's comparable with 2005. Before that, 1995 was hyperactive, and so was 1969. Anything above 16 is a huge deal in the Atlantic, and we're all used to high numbers now because of the warm AMO cycle for the past 15 years and that will continue for at least another 15.
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Quoting Drakoen:


Even bigger spread between 13 and 28...


Yep yielding an (unreliable) average of 20.5.
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Quoting Levi32:


Indeed. 2005 may not be considered such an anomaly if we happen to bust 20+ storms this year.


My thinking exactly.
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1156. Levi32
Quoting Drakoen:


Even bigger spread between 13 and 28...


Indeed. 2005 may not be considered such an anomaly if we happen to bust 20+ storms this year.
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1154. BtnTx
How does one get informed when they are banned?
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Quoting Grothar:


It is usually in the upper 70's to lower 80's, but the nights can often be very cool. It is a great city, great restaurants. Just carry a jacket whenever you go out. Very nice time of year to go there. If it rains, don't blame me.
Thank you. This will be her first time to Canada so she asked me to find out.
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Quoting Levi32:


I see a pretty fair spread from 12-19 with 14.4 being the average since the warm AMO cycle started in 1995.


12-19 is the low to high but overall the numbers are not excessively high for any year if you exclude 2005. To me, that says don't expect hyperactivity just because we have La Nina on the horizon and high SST.

You are correct about the average. My numbers for this season are 14/7/4 or 5 posted from mid May.

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1151. Grothar
Quoting stormwatcherCI:
I just had to ask her and she said Toronto.


It is usually in the upper 70's to lower 80's, but the nights can often be very cool. It is a great city, great restaurants. Just carry a jacket whenever you go out. Very nice time of year to go there. If it rains, don't blame me.
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1150. Drakoen
Quoting Levi32:


I see a pretty fair spread from 12-19 with 14.4 being the average since the warm AMO cycle started in 1995.


Even bigger spread between 13 and 28...
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Quoting Ossqss:
Interesting :)




Warm anomalies migrating westward.
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Quoting ShenValleyFlyFish:


You've been banned. No one can see your post.
Nope. If he/she was banned they wouldn't be able to post. This is said from experience. LOL
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1147. Levi32
Quoting Tropicsweatherpr:
Levi.if the anomalies warm again in the Gulf of Guinea,what are the implications for the tropical waves that emerge Africa?


A warmer Gulf of Guinea generally lessens the strength of the African Easterly Jet due to a decreased temperature gradient between the gulf and the Sahara Desert, and thus the tropical waves are weakened as well. I am inclined to believe the ECMWF forecast though, which forecasts cooling of the Gulf of Guinea during the summer, which would tend to strengthen the wave train.
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Quoting Ossqss:
Interesting :)


Why?
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1145. Ossqss
Interesting :)


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Quoting Grothar:


Which part? Lot of territory there.
I just had to ask her and she said Toronto.
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1143. Levi32
Quoting kmanislander:
If we look at the ten Neutral and La Nina years highlighted by the Doc in his post above, we see one interesting feature and that is that with the exception of 2005, which I consider to be an anomalous outlier year, all the remaining nine years are remarkably close together on the numbers. Is there a message there ?.



I see a pretty fair spread from 12-19 with 14.4 being the average since the warm AMO cycle started in 1995.
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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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