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Why Arctic sea ice is shrinking

By: Dr. Jeff Masters, 10:25 PM GMT on February 20, 2007

Second of three vacation blogs from Dr. Masters. Enjoy.

Since 1979, coverage of Arctic sea ice has shrunk by about 10% in winter and 20% in summer. The vertical thickness of the ice has also shrunk. According to the "official" Intergovernmental Panel on Climate Change (IPCC) report in 2001, Arctic sea ice decreased in thickness by about 40% between 1958 and 1997. This figure came from submarine sonar measurements taken over five cruises in the autumns of 1958, 1960, 1962, 1970, and 1976 when compared with three cruises in the autumns of 1993, 1996, and 1997 (Rothrock et. al, 1999). However, according to modeling studies by Holloway and Sou (2001), these results are highly uncertain, since not all years or locations in the Arctic were sampled. They found that if the first five cruises had been done just one year earlier (September 1957, 1959, 1961, 1969, 1975) and the three latter cruises had been done one year later (September 1994, 1997, 1998), the sonar measurements would have shown only an 11%-15% decrease in thickness. Arctic sea ice varies greatly in thickness, and currents and winds are always pushing the ice around, making it difficult to measure how the average thickness has been declining.

Warmer air and water temperatures have contributed to the sea ice decline

Annual average surface temperature has increased about 1 degree C since 1980 over the Arctic, which accounts for much of the sea ice melt. In addition, some melting has occurred from beneath the ice, due to warmer ocean waters. Global warming has heated up both the North Pacific and North Atlantic waters significantly over the past 30 years. Warmer waters have been brought into the Arctic Ocean from the Pacific via an ocean current flowing through the Bering Strait between Alaska and Russia, and from the Atlantic via an ocean current flowing northwards along the European coast.



Figure 1. The Arctic Oscillation (AO) index from 1899 - 2006. The AO is a measure of the difference in surface pressure between the north pole and about 45 degrees north latitude. Image credit: Dave Thompson of Colorado State University.

Wind patterns are a major cause of sea ice loss


The Arctic Oscillation is an observed natural pattern of surface pressure variations in the Northern Hemisphere. The "positive index" of the AO is defined when the surface pressure is below normal at the north pole and above normal at about 45 degrees north latitude. Positive Arctic Oscillation conditions steer storms farther north, bringing stronger surface westerly winds in the North Atlantic and warmer and wetter than normal conditions to the Arctic and northern Europe. The winds and ocean currents during the positive Arctic Oscillation mode tend to drive sea ice from west to east along the north shore of Canada, then out of the Arctic Ocean through the channel of water to the east of Greenland (Fram Strait).

When one looks at the wintertime pattern of the Arctic Oscillation (AO) over the past 100 years, a mostly random pattern of positive and negative AO modes is apparent (Figure 1). However, one anomalous period is very striking: a string of seven consecutive years with a positive AO, including two years (1989 and 1990) with the highest AO index ever observed. During this period, strong westerly winds rapidly flushed more than 80% of the oldest, thickest sea ice out of the Arctic Ocean, leaving most of the Arctic covered with ice less than three years old (Figure 2). Younger ice is much thinner, and melts much more readily. Rigor and Wallace (2004) estimate that at least half of the loss of sea ice in the Arctic since 1979 is due to these six years of strange weather with very low surface pressure over the Arctic. Did climate change cause this unusual pattern between 1989 and 1995? It is possible, but no one has published any papers showing how this might have occurred. For now, the assumption is that this major loss of Arctic sea ice due to wind patterns between 1989-1995 is natural.

The big concern is that since the strange positive Arctic Oscillation years of 1989-1995, a number of years with negative AO have occurred. Normally, during negative AO years, ice extent and thickness increase in the Arctic. But instead, ice extent and thickness during 2002-2006 have shown an unprecedented series of record minima, giving rise to fears that we are on our way to an ice-free Arctic later this century.



Figure 2. The change in age and thickness of sea ice between 1987 and 2005. In 1987, most of the Arctic sea ice was old and thick, generally more than ten years old. A period of strong positive Arctic Oscillation conditions between 1989 and 1995 created winds and currents that flushed most of this old ice out of the Arctic Ocean, through Fram Strait to the east of Greenland. The new ice that replaced the old ice is much thinner. Image credit: Rigor, I. G., and J. M. Wallace (2004), "Variations in the age of Arctic sea-ice and summer sea-ice extent," Geophys. Res. Lett., 31, L09401, doi:10.1029/2004GL019492.


This is the third in a series of five blogs on climate change in the Arctic that will appear every Monday and Thursday over the next two weeks. Next blog: Future abrupt loss of Arctic sea ice.

Also, be sure to visit our new Climate Change blog, written by Dr. Ricky Rood of the University of Michigan.

Jeff Masters

References
Holloway, G. and T. Sou, 2001, "Has Arctic Sea Ice Rapidly Thinned?", Journal of Climate 15, p1691-1701, 2001.

Rigor, I. G., and J. M. Wallace (2004), "Variations in the age of Arctic sea-ice and summer sea-ice extent," Geophys. Res. Lett., 31, L09401, doi:10.1029/2004GL019492.

Rothrock D.A., Y. Yu, and G.A. Maykut, 1999: "Thinning of the Arctic sea ice cover." Geophys. Res. Lett., 26, 3469-3472.

Climate Change

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

Very interesting blog. Thanks Dr. Masters.
Very interesting reading! Thank you!
Great read! Looks like an interesting topic to explore & like it may be a long vacation:)

As Aaron put this up I posted a pic a Favio, surface map (the 953mb Low), duldrums & a mention I couldn't get into FSU on the last blog.
Very nice blog, I always enjoy reading the blogs and learning. Thanks and have a great day.
So is there anyone in the blog this evening? If so how's everyone today.I live here in Mobile and it's been kinda muggy today and it's the last day of Mardi Gras.
Hey Juster.
Hey Ryang how ya doing?
hi Ryang, Catastrophe.
Isn't the new TSR coming out tomorrow? I think that's what it's called. It's something about El Nino & La Nina & Neutral conditions it the new update. I think it talks about what kind of conditions might be coming up for the Hurricane Season. I may be wrong.
Juster doing good!
Pottery you know about the fight!
Hey Pottery, what cha up to other than blogging?
Hey all, this neg AO & continued ice loss is intreging.

catastropheadjuster~ The CPC put out they expected La Nina for the 2nd 1/2 of the year.
Hello guys Favio continues to get better organized...

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Don't bother reading this, i was being nosie and it isn't none of my business. Sorry
Catastrophe, other than blogging, I've been at our Carnival celebrations. Fantastic day, now I,m tired...............
I take my questions back I'm sorry it isn't none of my busness.
Hey sheri!
When I google it in about the ice & the AO I get a sciencemag site with a breif thing on the current melting during a neg phase being a "hangover" from the extrememly pos phase that preceded this. What makes me leary about the source is they want $10 to read it. Most peer approved stuff doesn't cost to read.
Enso update is due in a few hours i expect Neutral conditions are indeed in place.we'll see what they have to say.
Invest 97S also looking organized with very impressive banding features...




Region 3,4 (the one that matters) hit 0. It's gonna take a 3 months average of neutral conditions to make it offical.
Quick post then i have to go for the night.

The Indian Ocean has had to many storms this year. Favio has made a loop around the southern half of Madagascar without making landfall on the island. Does anyone think that is weird?

Bye everyone for the night!!
Hey H23 where have ya been? Haven't seen you around. Or I just haven't been in the right place at the right time.LOL Did I here that the new Autralian thing is coming out tomorrow i think that what was said.
CIMSS MIMIC of FAVIO.. Vmax 109ktsLink
Here's a page you can animate the ice over the last 30 days.
Skye, good evening. Why is the Northern hem. warming faster than the southern ???????? Or am I wrong here ?
Mimic was interesting, Favio has really strengthed today.

Wave forecast for Favio, mostly 15-30 ft
Catastrophe , I did'nt think you were being nosie.
Developing Tropical Low
10.0S 92.0E - 30 knots 1000 hPa

moving west-southwest at 10 knots
maximum winds 40 knots

The tropical low may form into a tropical cyclone in the next 12 to 24 hours

next warning at 4:30am UTC from Bureau of Meteorology in Perth.
Pottery your right, it's warming faster than the south... Not an easy question as to why, one theory is the way more greenhouse gasses are released in the N Hem & the air flow patterns do initally shove air more poleward. So the N Pole would take the brunt. It triggers reactions like the lose of the ice reflection heat back out to space. N Hem oceans playing more of the heat sink, making the Artic melt faster. The N Pole & S Pole are conected through an ocean current, but the water has to cool to sink to get there & even the current is slowing. The theory makes sense & I haven't seen much for substanciated arguements against it.
Did Skyepony see the Delta Launch at Sunset the other day?
Thanks Skye. I notice a Blob of warmer sst off Africa already. A little early for that ?
Hey everybody,im having trouble getting the new 18UTS GFS 384 HOUR LOOP,can anyone please post it.Thanks!
Re: the thinning Arctic ice. There is a library of historical information locked up there and its getting lost fast. Have we got all the info we need before it dissapears completely ? I have my doubts.
I'm not talking only of weather related stuff in the ice. There is bacteria, spores, seeds, dust, ash, all manner of stuff that isnt available elsewhere.
Hi 882MB. Sorry, cant help there. Looks like everyone else dissapeared !
Well now that we out of the cold here in FLORIDA its time to bring in some warm temperatures and much needed RAIN. I JUST SAW THE NEW 18UTC GFS LOOP AND IT SHOWS A STALLED FRONT OVER CENTRAL SOUTHERN FLORIDA WITH LOW PRESSURE MOVING ALONG IT NEXT MONDAY THROUGH WEDNESDAY. YES WE NEED THE RAIN BEACUSE HAVE YA HEARD LAKE OKEECHOBEE IS ALMOST 5 FEET BELOW NORMAL, WE NEED ALOT OF RAIN!
Oh good that last post made it as I got tossed offline:)

I dorked that launch Patrap, did catch a nice pic of it on WU though...
& yeah the blob of warm water off of Africa is ~1.5 to 2C warmer than it should be..

Skyepony one thing iam concerned is seeing how SST'S are looking quite warm similar to what we saw back in 2004 and 2005.Hopefully these anomalies will cool of some in time for this hurricane season.


Wow pretty soon we may be looking at 3 SYSTEMS IN THE SOUTHERN INDIAN OCEAN, BESIDES FAVIO AND 97S RIGHT BEHIND 97S ANOTHER LOW PRESSURE WITH ALOT OF CONVECTION IS LOOKING LIKE ITS ALSO STRENTHENING.THESE SYSTEM ORIGINATE OVER INDONESIA AND TRAVERSE THE SOUTHERN INDIAN OCEAN WHERE IF CONDITIONS ARE FAVORABLE TROPICAL DEVELOPMENT IS LIKELY, SIMILAR TO OUR SEASON WHERE AS OUR TROPICAL WAVES ORIGINATE OVER AFRICA!
IDW23100
40:3:1:24:AASBBBE999:11:00
SECURITE

HIGH SEAS WEATHER WARNING FOR METAREA 10 ISSUED BY THE
AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING
CENTRE PERTH AT 2344UTC 20 FEBRUARY 2007

Gale Warning FOR THE WESTERN AREA

Please be aware, wind gusts can be a further 40 percent stronger than the
averages given here, and maximum waves may be up to twice the height.

SITUATION
At 2300UTC a developing tropical low was located within 40 nautical miles of
Latitude nine decimal six degrees South [9.6S]
Longitude ninety one decimal three degrees East [91.3E]
Recent movement west southwest at 10 knots.
Maximum winds: 30 knots.
Central Pressure: 1004 hPa

AREA AFFECTED
Within 60 nautical miles of the centre extending to 120 nautical miles of the
centre in the southern semicircle.

FORECAST
Low may develop into a tropical cyclone in the next 12 to 24 hours
causing clockwise winds 25/33 knots increasing to 30/40 knots in the southern
semicircle, rough to very rough seas and moderate swell.





At 1100UTC 21 February: Within 40 nautical miles of ten decimal five South
eighty nine decimal four East
Central pressure 1000 hPa.
Winds to 35 knots near centre.
At 2300UTC 21 February: Within 70 nautical miles of eleven decimal six South
eighty six decimal nine East
Central pressure 995 hPa.
Winds to 40 knots near centre.

Next warning issued by 0500UTC 21 February 2007.
Hello fellow wunderbloggers !
Greetings from Indonesia !
Even here unusual weather affects us, on 5 pm Sunday ( february 18th 2007 ) the city of yogyakarta in central java was struck by what seems to be a tornado ( F0 most likely). It damages and destroyed thousands of homes, public utilities and offices. The winds were strong enough to pull off roof tiles, snap trees in half and throw bicycle into cars, with funnel like structure extending from the cloud. Many people were injured but thankfully nobody got killed.
REINSTITUTE RANDREWL

--MisterPerfect, WUSPIS, CEO
JustSouthofEquator~ Glad noone was killed. I was just noticing in Stormydee's blog Indonesia had 5 earthquakes today. Sounds rough in your part of the world at the moment.
Central Indian Ocean
-------------------------
Developing Tropical Low
9.7S 90.0E - 25 knots 1002 hPa

moving west-southwest at 12 knots
maximum winds 30 knots

The tropical low may form into a tropical cyclone in the next 12 to 24 hours.

This is the last advisory from TCWC Perth, the system will be monitored by RSMC Reunion.

the next advisory is at 12:30pm Wednesday.
Is older ice more like glacier ice, in that it is more crystaline and can resist melting better, or does that take a looong time to happen? I mean is the new ice only thinner or is it more prone to melt too?
Summary: The 2006/07 El Nio has ended...

The 2006/07 El Nio has ended. All the main ENSO indicators show that neutral conditions have returned to the Pacific Basin. Along the equator, sea-surface temperatures are cooling rapidly and have been below their El Nio thresholds for about a month now. The Trade Winds have mostly been close to or somewhat stronger than normal since December, the SOI has been neutral for three of the past four months and central-western Pacific cloudiness is close to average. Computer models indicate further cooling in the Pacific, with a La Nia not out of the question (see third paragraph).

What does this mean for Australia? Firstly, while the end of the El Nio would normally be associated with a return to more normal rainfall patterns, it should not be seen as a precursor to drought-breaking rains. This particularly applies to water supplies in parts of eastern and southern Australia, which in some instances require several years of healthy rainfalls to recover to a satisfactory level. Nonetheless, we can be cautiously optimistic that there will be a general easing of dry conditions in drought-affected areas over the next one to two seasons.

A La Nia in 2007?
The chance of a La Nia developing in 2007 is thought to be higher than the long-term average (which is about one in five or 20%) because (a) they have a tendency to follow an El Nio; (b) the El Nio has decayed somewhat earlier than normal thereby giving time for a La Nia to begin developing during the critical March to June period; and (c) a large pool of cold sub-surface water has developed in the central to eastern tropical Pacific Ocean. La Nia events are generally associated with wetter than normal conditions across much of the eastern half of the country from about autumn.

ENSO UPDATE!
is la nina bad for hurricanes in the atlantic?
... On this date in Indiana weather history...

1779 it rained all day on the Army under George Rogers Clark
as they crossed the flooded Wabash River near St
Francisville Ferry... on their advance towards British held
Vincennes.
its very interesting to ready this thnx dr jeff master u keep the blog interesting for the whole year :)
hurricane23 between 0 and 1 degree warmer then normal doesnt mean that much if it is higher then 1 degree and if that are large spots we should worry
tornadodude if u were here last year u would have known :) but it was bad for hurricanes in the atlantic
hi. Definitely warmer than average SST off Africa. Hurricane23 said that hopefully the thing will cool down before June. I cant see any reason for that happening at all. Why would it cool ? There is less and less cold water entering the conveyor belt all the time..........
A slideshow of Yesterdays Revelry..The Real look..Link
Biff~ Yeah the new Ice is more prone to melt, hasn't been compressed yet. From what I understand ice as young as 10 years old is "old ice" & more resistant to melting.

As for ENSO~ The CPC is predicting La Nina conditions for the 2nd 1/2 of the year. I updated about it my blog a few days ago, exactly where all the #s are & all. If your interested check it out, it will be the last day I have the graphics up til I update next Monday when the next CPC report comes out.
Pottery~ High surface winds or upwelling would help cool the Atlantic.

Right now a little case of the duldrums has set in just off Africa so for short term, we could expect that spot to grow even warmer.

Yep Skye, thanks. But during the summer the winds are generally more calm than now. So cooling would have to come from an upwelling, and that becomes less and less likely. Its going to be interesting anyway.
I am glad that lake Okeechobee is 5 feet low. I live in Cape Coral where the river runs into the gulf. Whenever the lake is high they release almost 80,000 gallons of fresh water a second down our brackish river. Kills alot of blue crab and life along with blue green algae blooms. Corps are supposedly working on a plan. Big Money. I say stay away rain...this is south Florida...no rain in winter.
Good Morning everyone. boy about 6:30 this morning it was doing some raining I mean very heavy and got a little rough. It woke me up and I looked out the bedroom window and I couldn't even see our pool it was raining so hard. But it was like someone threw a light switch and it just stopped. Know all it's doing is drizzling, but they said it suppose to clear up by lunch and be a nice day. I read the new up date so are they saying La Nina will probaly take effect during hurricane season? I'm still trying to understand all this stuff.
The Carribean is having way clamer than normal winds right now, that may change before season begins. Can see the affects on the sst anamoly graphics. Last season, they stayed higher than normal cause of El Nino. Your right though, we probibly shouldn't hope that as a savior this season as neutral conditions will cut those winds about as much as a la nina would. Atleast the doldrums are at a minimum for the Atlantic, lets hope they stay that way.
Re : the banned. We as a group need to try to diffuse some of the quarrelsome behaviour that results in people being banned. Some guys have an ego bigger than their brain. I was not on when it occured. But if a couple people had stepped in maybe it would have cooled down ? Getting banned is pretty futile . Admin has a job to do, and frankly I approve of their actions. If I want Bachanal and stupidness I"ll go to the TV...............
What is duldrums? Also shouldn't the Alantic start warming around this time? why would it be cooling down? Sorry I just don't understand. to me i think this time of the year it should start warming cause hurricane season is around the corner. I know I'm probaly wrong so would someone take a minute and explain it to me. Sorry but Thanks for taking the time to tell me.
Guys I'm not trying to bother you'll so please don't get angry with me.
Having said that...I realy hope to see those guys back on here........SOON
Who got banned? Was it Randrewl & MichealSTL
Hi Catastrophe. No need to sver feel sorry for asking questions here. We learn by asking,right ?

The doldrums are areas of ocean where the winds are calm for long periuods. If there is no wind, and the air above the sea is hot, the sea surface warms up.

And yes, you are right, the Atlantic is due to start warming up, but there is an area off Africa that is unusualy warm for this time of year.

We were trying to figure out what could cool it now, to bring it back in line with " normal".
Yes,Rand and STL were banned.



CPC says La Nina on the way in 3 months.
Hey sheri!I sent you a few links a couple of days ago on how to understand la nina & nino affects across the basin.
Catastrophe, Further, you said that the Atl. should start warming now because hurricane season is around the corner. But bear in mind that the warm water comes first... The storms cant get going unless the water temp gets up, because warm air holds more moisture than dry air.
Kris that will probably mean drought conditions for us across florida...
And,if it last to next winter,more arctic cold fronts.
Catastropheadjuster,until Rand comes back atmos's blog is the new severe weather blog,mine will also be covering severe weather.
I'll be back laters.........
bye pottery.
Alot of things have to be at certain level in order for a tropical system to flourish warm SST'S is not eveything as we saw in 2006.SAL will have to watched in the coming months because if right now were august nothing would develope the way things are in the basin.It really put the caps on the 06 season.

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Yeah,but the SAL is usually strong this time of year.
Florida hurricanes in neutral:



Contrast with La Nina:



Yea kris ive seen those maps they both pretty much indicate busy times for florida.My picks for areas seeing the most activity this season are florida and north carolina with florida seeing the most activity.Look forward to see what Phil Klotzbach and others have to say on the all important steering patterns that might be in place.
POTTERY: Thank You one more thing if it stays warm will that mean we might see a bad season cause don't warm water fuel hurricanes?
Yes sheri(that's your name,right?),but what he meant was that even after the water gets warm enough...it still takes a while for hurricane season to get going.You need the water to evaporate and moisten te air,and you need the wind shear to slow down.
Why was MichaelSTL banned? He was about weather.
Shear conditions seem to be abating a little already, which is surprising.
He hacked into Rands Blog
Sheri~ your not bugging anyone, questions are good. I just tend to blog & walk away & come back, catch up & do the same. Thanks for clearing up the doldrums pottery:) & Yes warm sst alone mean nothing, many other factors come to play.

Two things about the SFL drought, it's slowing going fairly state wide, & nearly every year Fl gets slammed by 'canes it was droughtish, though the studies have shown we can have the winter/spring drought & not have hurricane activity. Consider the drought upping our odds.
The ICFDs reveal a La Nia increase relative to neutral in hurricane landfalls along the East Coast, that is not present in Florida. During a cold event, the probability of two or more hurricanes hitting the East Coast is 18% vs. only 9% during a neutral event (Fig. 3). In Florida, the probability of two or more hurricanes making landfall is 22% during a cold event and 20% during a neutral event No warm phase year has produced more than one hurricane landfall in either Florida or along the East Coast. For both areas there is a decrease in hurricane landfalls in the warm phase.



The number of hurricanes that made landfall in Florida each year between 1900 and 1998. El Nio years are indicated in red, neutral years are shown in green and La Nia years are indicated in blue.



The number of hurricanes that made landfall along the East Coast each year between 1900 and 1998. El Nio years are indicated in red, neutral years are shown in green and La Nia years are indicated in blue.
I forgot to say hi.
As for stepping in on Rand's & STL's arguement, we usually did. Very few was around that night. Aaron left his thoughts in his blog as to why he banned them, they both broke the terms of agreement. From the sounds of it they both got way out of line.
Sheri~ your not bugging anyone, questions are good. I just tend to blog & walk away & come back, catch up & do the same. Thanks for clearing up the doldrums pottery:) & Yes warm sst alone mean nothing, many other factors come to play.

Two things about the SFL drought, it's slowing going fairly state wide, & nearly every year Fl gets slammed by 'canes it was droughtish, though the studies have shown we can have the winter/spring drought & not have hurricane activity. Consider the drought upping our odds.



2004 was a horrible drought year...and look what happened.
Skye, Rand was cursing and going on about it in auburns blog at around 4am EST yeasterday. I don't think he slept all night
Typically during LA NINA years the jet stream rides further north and prevents fronts to come very far south there for outside the the rainy season we are dry down here in the southeast.
Hey H23 & WBK: Yes I got them thank you. I'll be able to learn from them and sometimes I like to ask questions. Sometimes I can learn from people explaining it to me better. but i like getting your info cause i can go look at it and learn from it to.
You all probably see this question a lot, and forgive me for posting it again.

What effect does La Nina have on the FL weather outlook for spring and summer? How does it effect hurricane season?
No problem sheri...

It also tends to result in a pattern in which we have a strong Atlantic ridge that is located further to the east as the Azores High, resulting in a year like 1999 (not 2004/2005) pattern. This tends to mean a strong trough located right off the southeast/eastern U.S. coast, meaning that most Cape Verde-type storms that form far east in a La Nina pattern will likely curve away from Florida and miss the U.S. eastern coast or, if they make landfall, hit the Carolinas.Its all about timeing with tropical systems.

Typically during LA NINA years the jet stream rides further north and prevents fronts to come very far south there for outside the the rainy season we are dry down here in florida amounting to drought conditions arcoss the state.

Also wanted to mention while east hits are less common in La Nina years, Florida tends to receive more southwest hits during La Nina years than during neutral/El Nino years.

During La Nina years is the GOM region usually in the clear cause i see where you'll are saying Florida usually gets pounded during La Nina and something about the east coast and I just didn't know if people like Mobile,Miss,NO,TX is clear in them years. I thought i read somewhere this year where they raised the percentage up for the GOM. I may not be making no sense I don't know.
So by that Graph you showed La Nina could be a quite year to, I always thought La Nina made Hurricane Season worser. Or that's what I've always heard. Or am i just getting all messed up?I promise I'm not stupid or trying to be difficult.
H23 & WBK are you'll gone and am i just talking to myself? I was enjoying the talk we was having.
I'm listning
Number wise they could be quite active but in la nina years alot systems recurve before reaching the united states.


I'm still here.
And to answer your question,the GOM and Carribean is normally more active in La Ninas.
There are also factors that can complicate the prediction of tropical cyclone steering. Trough interactions may affect the track of a tropical cyclone The position of an upper-level trough can play a role in the direction that a tropical cyclone will move. Also, tropical cyclones are known to modify their own environment. These modifications can make it difficult to predict steering.
And not just that,H23.It ocsillates from week to week,sometimes a trough,sometimes a ridge,usually.In some years,there is mostly a ridge(2004),or a trough(2006).
the GOM and Carribean is normally more active in La Ninas.


Thats good to know
Well lets just hope they stay away! New baby girl due on July 10th! Can't just stick around like we used to anymore! Hello everyone long time no talk!
Hi progressivePulse.Haven't seen you in a while.
Tracks of landfalling hurricanes indicate that East Coast landfalling storms tend to form in the central Atlantic and curve northward just off the Leeward Islands while Florida landfalling storms are more likely to form further west. There are less storms forming in the central Atlantic, where East Coast landfalling hurricanes tend to form, during neutral years than during cold years. This may explain why there are fewer hurricanes making landfall along the East Coast than in Florida during neutral years.

Hey progessive pulse!What u been up too!
Hi ProgressivePulse
When is La Nina forecast to Die out?

It's going to be quite a season
La Nina isn't here yet TS2.What are you talking about?
Sorry. i've got about 10 things in my mind just now
There's a good chance La nina conditions will develope somewere between march and june.Some strong El Ninos have been followed by neutral conditions or by weak La Ninas.
Doing well everyone! Busy with wifey and work or course, how are you all?
Very active times across the indian ocean!


I'm doing good,ProgressivePulse.
Good to hear from you progressivepulse goodluck with your baby due in a few months.
Rand is back!Go to atmos's blog.
120. Inyo
does anyone else think the ENSO cycle is increasing in the speed of its fluxuations?


also, this El Nino had no effect on most of the US. In fact, California had La Nina type conditions. Makes you wonder what the La Nina will do
Inyo~ Yeah, I see how in the past when it veried above or below the - or + .5 threshold it stayed there for atleast the next 5, 3 month average incroments. That's the minumum amount of time to make the La Nina or el Nino official. It's never gone above or below & ended before 5 months except in 1962, 1967 & 2005. This year offically it will probibly make it 5 months & be an offical El Nino unlike 2005 unoffical La Nina. Close though.

I don't know if I buy the big influence of ENSO as to where the high will set up for the most part & even it's affect on #s is limited. Look at 2004. That was alot for el nino year. 2005 was a cold side of neutral & an unoffical La Nina year & much land was hit as well. '79 was the warm side of neutral~ alot of landfalls. Alot of factors.
FL has been getting it's share of El Nio tornados.
Posted By: hurricane23 at 11:56 AM CST on February 21, 2007.

Very active times across the indian ocean!


I hope that the Atlantic doesn't look like that in 6 months...
Posted By: weatherboykris at 10:04 AM PST on February 21, 2007.

Rand is back!Go to atmos's blog.


huh??????
Gamede looking quite impressive forcasted to reach 60kts which will probably intensify futher then currently forcasted if current intensification continues.


Indian Ocean is hot right now.


The weather across large areas of the U.S. is going to be pretty interesting later this week - heavy snow to heavy rain and flooding to severe storms and tornadoes.
More Tornadoes? We don't need anymore Tornadoes
The 2007 hurricane season has the potential to to end being very active if neutral conditions are around.We saw what took place in 2004-2005.

Gamede continues to get oraginzed and has the looks of a power cyclone is in the making .

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130. 882MB
Yes indeed Hurricane23, I am also predicting a very ACTIVE HURRICANE SEASON. NOW IT WILL ALL DEPEND ON THE STEERING CURRENTS!
her is what the STEERING CURRENTS look like right now

lol
Bad news for Africa, Favio ain't done.



Just about to make landfall


Worst winds on the SW side as well, another not good.

Looking at MIMIC it looks like that weak spell was an eyewall replacement. All done now.
Indeed doesn't look good for those folks in the path of favio.

Gamade is developing a strong CDO.


Favio is gonna smack the same flooded area I've posted about in the last 6 weeks.

As Floods Continue, Mozambique Now Prepares for Cyclone
10 min sustained winds stats

0600am UTC 22Feb 2007
Metro France: RSMC Reunion

Forte Tempte Tropicale Gamede
55 knots with wind gusts up to 80 knots

Cyclone Tropical Intense Favio
95 knots with wind gusts up to 135 knots

Dpression Tropicale 11R
30 knots with wind gusts up to 45 knots
Good Morning {{Dr.Master's}}.
dry air continues to dominate the antilles and caribbean
cimss MIMIC FAVIO...Link
cimss MIMIC Gamede Link
Good morning,

Looking at Gamade this morning its looking extrememly well organized with very well established banding features...




Cyclone hits flooded Mozambique

Cat 4 worst to hit the area in recorded history.