Loop Current Eddy cuts off; oil danger to Keys now greatly reduced

By: Dr. Jeff Masters , 2:24 PM GMT on May 28, 2010

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A major ocean current re-alignment is underway the Gulf of Mexico right now, and the new configuration that is developing greatly reduces the threat of oil entering the Loop Current and affecting the Florida Keys and U.S. East Coast. As I explain in my Loop Current Primer, the Loop Current is an ocean current that transports warm Caribbean water through the Yucatan Channel between Cuba and Mexico. The current flows northward into the Gulf of Mexico, then loops southeastward just south of the Florida Keys (where it is called the Florida Current), and past the western Bahamas. Here, the waters of the Loop Current flow northward along the U.S. coast and become the Gulf Stream. With current speeds of about 0.8 m/s, the Loop Current is one of the fastest currents in the Atlantic Ocean. Every 6 - 11 months, the top bulge of the Loop Current cuts off, forming a 250-mile diameter circular eddy in the middle of the Gulf of Mexico. This clockwise-spinning eddy is filled with warm water from the Loop Current, and is called a Loop Current Eddy. The main body of the Loop Current then takes a fairly direct eastward path from the Yucatan Channel to the Florida Keys.

Over the past two days, surface currents in the Gulf of Mexico have aligned to form a Loop Current Eddy, as seen in the analysis of surface currents done by the U.S. Navy (Figure 1, and see also a 30-day animation of the eddy forming.) It remains to be seen if the deep water currents have followed suit, and a stable Loop Current Eddy cannot exist until the deep water currents also cut off into a clockwise-rotating ring of water at depth. A NOAA Hurricane Hunter aircraft is out over the Gulf of Mexico today dropping expendable buoys and current probes to determine if a stable Loop Current Eddy has formed. Roffer's Ocean Fishing Forecast Service has a nice discussion on the Loop Current Eddy formation.


Figure 1. Comparison of surface currents in the Gulf of Mexico on May 19 (top) and May 27 (bottom) as simulated by the HYCOM model. On May 19, the Loop Current made a large northward loop into the Gulf, and was able to transport oil from the near the spill location southwards through the Keys. By May 27, this loop had cut off, and new oil moving southwards from the spill will now be trapped in the clockwise rotating Loop Current Eddy that is cut off from the Loop Current. Note on the west side of the Gulf of Mexico, off the coast of Texas, there is an old Loop Current Eddy that cut off from the Loop Current in July 2009. This eddy cut off in the same location as this week's eddy, and has drifted west-southwestward at 3 - 5 km per day over the past ten months. Image credit: U.S. Navy.

If the eddy does remain in place, it will greatly reduce the chances of oil making it to Cuba, the Florida Keys, and beyond. Any oil moving southwards from the spill location will now become entrained in the eddy, and will move in a 250 mile-wide clockwise circle in the east-central Gulf of Mexico. A small portion the oil will get shed away from the eddy's periphery and make it into the Loop Current and waters surrounding the eddy, but the concentrations of oil doing so will be small. Keep in mind, though, that during the first 1 - 2 months that a Loop Current Eddy forms, it is common for the eddy to exchange substantial amounts of water with the Loop Current, and in some cases get re-absorbed into the Loop Current. A 1-year animation of the Loop Current shows that the last Loop Current Eddy, which cut off in mid-July 2009, experienced a 2-week period in early August when it re-attached to the Loop Current. A significant portion of any oil entering the eddy during a period of re-attachment will be able to enter the Loop Current and flow past the Keys.

One bad result of the eddy breaking off is that now we have an extra source of heat energy for passing hurricanes during the upcoming hurricane season. Loop Current eddies have high-temperature water that extends to great depth, and hurricanes passing over such eddies often undergo rapid intensification. Hurricanes Katrina and Rita of 2005 both underwent rapid intensification as they passed over warm Loop Current eddies in 2005. The formation of a Loop Current Eddy during hurricane season means that a much greater portion of the Gulf of Mexico has deep, warm water capable of fueling rapid intensification of hurricanes.

Oil spill update
Light offshore northwesterly winds are expected to blow over the northern Gulf of Mexico today through Saturday, resulting decreased threats of oil to the Louisiana shore, according to the latest trajectory forecasts from NOAA. These offshore winds may be able to transport oil southwards into the Loop Current Eddy that just formed; a streamer of oil moving southeastward into the Loop Current Eddy is visible in yesterday's NASA MODIS imagery (Figure 2). Winds will shift to onshore out of the south on Saturday night, then shift to southwesterly by Tuesday. The long-range forecast from the GFS model indicates continued southwesterly winds all of next week. If this forecast verifies, we will see our greatest chances yet of significant amounts of oil reaching the beaches of Mississippi, Alabama, and the Florida Panhandle.


Figure 2. Visible satellite image of the Gulf of Mexico taken at 2:55pm EDT Thursday May 27, 2010, by the MODIS instrument on NASA's Aqua satellite. Thin streaks of oil can be seen moving southeast and then southwest around the eastern side of the new Loop Current Eddy. Image credit: NASA.

Oil spill resources
My post, What a hurricane would do the Deepwater Horizon oil spill
My post Wednesday with answers to some of the common questions I get about the 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
NOAA trajectory forecasts
Deepwater Horizon Unified Command web site
Oil Spill Academic Task Force
University of South Florida Ocean Circulation Group oil spill forecasts
ROFFS Deepwater Horizon page
Surface current forecasts from NOAA's HYCOM model
Synthetic Aperture Radar (SAR) imagery from the University of Miami

Central American disturbance
The Atlantic is currently quiet, with none of our reliable global forecast models predicting tropical cyclone development over the next 6 days. There is an area of disturbed weather (90E) just off the Pacific coast of Mexico that will be a major concern for southern Mexico and much of Central America over the next 3 - 4 days. The disturbance will bring heavy rains to Central America during the weekend, potentially bringing serious flooding rains to portions of Mexico, Guatemala, El Salvador, Honduras, and Nicaragua. NHC is giving the disturbance a high (>60% chance) of the disturbance developing into a tropical depression by Sunday. Wunderbloggers Weather456 and StormW have more on the tropics.


Figure 3. Satellite image of the Central American disturbance 90E this morning.

Join the "Hurricane Haven" with Dr. Jeff Masters: a new Internet radio show
Beginning next week, I'll be experimenting with a live 1-hour Internet radio show called "Hurricane Haven." The show will be aired at 4pm EDT on Tuesdays, with the first show June 1. Listeners will be able to call in and ask questions. Some topics I'll cover on the first show:

1) What's going on in the tropics right now
2) Preview of the coming hurricane season
3) How a hurricane might affect the oil spill
4) How the oil spill might affect a hurricane
5) New advancements in hurricane science presented at this month's AMS Conference on Hurricanes and Tropical Meteorology
6) Haiti's vulnerability to a hurricane this season

I hope you can tune in to the broadcast, which will be at http://www.wunderground.com/wxradio/wubroadcast.h tml. If not, the show will be recorded and stored as a podcast.

I'll be back with at least one update over the coming 3-day Memorial Day weekend. Have a great holiday!

Jeff Masters

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Quoting FloridaTigers:
I've always wondered, if a storm survives the trek over Central America/Mexico, does it retain its name from the basin of origin? I know storms get new names when they deteriorate and regenerate, but what about if it stays above TS level?


It gets renamed. Sometimes, if I remember correctly, they get unofficially referred to both names. ex. "Agatha-Alex"
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606. IKE
Quoting hydrus:
Did you see it Ike?


I saw it.
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Nice... I'm giving 80% that this will become a named storm.

I don't really see it moving to the NE, indicated by the map though...
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604. xcool
kaboom
Member Since: September 26, 2009 Posts: 2 Comments: 15684
Quoting photomunkey:
I've never seen mud blowing out from a point off-camera, below the riser before now, FWIW. Been watching the live cam every day since it first came on.


I'm with you here. you can see the arm of the ROV holding on to the BOP...maybe a slightly different angle, but there is more material "leaking" Also the BOA Deep 2 ROV (on CNN) is observing the "live feed" ROV (the one observing the riser)
Member Since: May 30, 2008 Posts: 0 Comments: 39
Quoting Chicklit:

I have several five gallon water bottles I routinely fill up at the grocery (have a 50-gallon fish tank!). Also, mostly what I'll get together is the canned stuff.
Yes, a generator is a life saver if only to keep the refrigerator running. Though this year, I'm thinking of getting a small fridge to keep downstairs rather than run my large one up here.
Smart. I also want to get a generator that way if the power goes out I can still be on the blog during the hurricane, lol.
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Quoting Chicklit:
My least favorite thing is getting the generator started. Will burn through the old gas and get new gas. Also have to check all my extension cords for tears. Oh yeah, and make sure the gas grill is working. I think I can manage to do that with some wings!


Hopefully you don't have last years gas in it. Our blended Florida gas goes bad very fast without proper additives in it. I just had to clean the fuel system completely out of my small Gen due to bad gas even with additives in it :(
Member Since: June 12, 2005 Posts: 6 Comments: 8188
Quoting photomunkey:
I've never seen mud blowing out from a point off-camera, below the riser before now, FWIW. Been watching the live cam every day since it first came on.

There is another view on the feed from another ROV. It is just mud swirling around in front of the camera. OK so far I think.
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Patrap, are you hearing any chatter on the channels about the BOP?

Man, the fluid harmonic stresses on that metal must be enormous! The vibrations will eventually shatter that steel (or iron) no matter how well it's made!
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Quoting MiamiHurricanes09:
I have to go buy one. It's going to be a pretty rough year in south Florida so I definitely need a generator, radio, portable t.v, etc... One think I recommend you don't buy now is food or water. Wait until late July to do that stuff.

I have several five gallon water bottles I routinely fill up at the grocery (have a 50-gallon fish tank!). Also, mostly what I'll get together is the canned stuff.
Yes, a generator is a life saver if only to keep the refrigerator running. Though this year, I'm thinking of getting a small fridge to keep downstairs rather than run my large one up here.
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Quoting FIU2010:


yup, and next tuesday we have the ones for CBS and NBC.
Thanks! I didn't know what day those were going to be on.
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I've never seen mud blowing out from a point off-camera, below the riser before now, FWIW. Been watching the live cam every day since it first came on.
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Quoting leo305:


I don't know, but there are more cracks on the pipe than before..

I heard they had stopped pumping mud and plan on starting again later today


You're a day behind...they restarted pumping last night
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Quoting Chicklit:
My least favorite thing is getting the generator started. Also have to check all my extension cords for tears.
I have to go buy one. It's supposed to be a pretty rough year in south Florida so I definitely need a generator, radio, portable t.v, etc... One think I recommend you don't buy now is food or water. Wait until late July to do that stuff.
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Quoting DentalPainDMD:
looks like a new leak on the BOP riser or more mud pumping? needless to say...something is happening on the live feeds


I don't know, but there are more cracks on the pipe than before..

I heard they had stopped pumping mud and plan on starting again later today
Member Since: April 17, 2010 Posts: 0 Comments: 1753
Quoting JamesSA:
More mud.


And a slightly different camera angle
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My least favorite thing is getting the generator started. Will burn through the old gas and get new gas. Also have to check all my extension cords for tears. Oh yeah, and make sure the gas grill is working. I think I can manage to do that with some wings!
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Quoting Jeff9641:
They are now mentioning possible impacts to C FL late next on news 13 in Orlando from 90E but only as enhanced rain. I'm sorry MiamiHurricanes but I think you will be wrong on this one buddy.
I think I will be right on this one, lol. I'm sorry I just don't see the remnants of 90E going towards Florida unless in can get into the GOM, and steering currents won't allow for that. Anyways, 90E is expected to strengthen even further, which in that case, it would move into the Caribbean.

*The person who is right gets a cookie. LOL.
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Quoting photomunkey:
BOP went boom, looks like. :(


Looks like drilling mud and at about the same levels as the first run of pumping...
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Quoting DentalPainDMD:
looks like a new leak on the BOP riser or more mud pumping? needless to say...something is happening on the live feeds
More mud.
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Quoting Chicklit:
Re: Hurricane Preparedness.
Okay, I'm convinced that now's the time to take preparations seriously (I live on a barrier island along east central Florida's coast). So this weekend (starting today already), I've begun to sort through the stuff in my hurricane shelter (downstairs) in order to make room in case I need it. I know everyone says "evacuate;" however, I have too many pets to reasonably do this and this house is constructed with a shelter. Also, I'm pretty high up in some dunes with about an acre of oaks around me so do have some protection. Anyway, I am now putting things in order, will get some more plastic containers this weekend, and make sure that I have a couple of blue tarps, a couple rolls of duct tape, and will be making up plastic, sealed boxes. One will have paper goods like paper towels, tp, etc. One will be a dry clothing box. And one will be a food box. This will help to shorten my preparations and if and when a storm does arrive here. Also, being prepared myself means I'll have time to be sure all of my shutters get put up and I can also help my neighbors, including my 83-year-old mother who lives across the street! Nothing's perfect. We've got to take stock of what we have (and don't have) and work within the parameters.
This is a good weekend to do it.
I just have a few things to do and yes, this is the weekend to finish
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looks like a new leak on the BOP riser or more mud pumping? needless to say...something is happening on the live feeds
Member Since: May 30, 2008 Posts: 0 Comments: 39
BOP went boom, looks like. :(
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Quoting FIU2010:


thanks, friend, dont forget to watch the local 10 hurricane special, tonight at 8pm.
Definitely. Tomorrow night is the WSVN one with Phil Ferro.
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Quoting leo305:


It is still early for "fast" intensification.. but I would not be suprised, the system is rather large, and it isn't THAT close to land "yet". It's getting more organized, once the sun goes down, that's when the convection will really begin to erupt over the core of the system (as many of these systems tend to do) and with an anticyclone over it, it should strengthen to the very list into a moderately strong tropical storm.. atleast that's my view on it, and the CMC kinda agrees (which is the model I am going with for now).
Well If it gets into the Caribbean I can agree on rapid intensification. But it's just too close to land for it too really intensify. And on the CMC, it's way off on intensity. There is no way a system in the middle of the subtropical jet stream can intensify to rapidly, regardless of having an anticyclone aloft. The only thing I could agree on with the CMC is the track, and i honestly don't like it too much.
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Quoting CybrTeddy:


Look how quickly the GOMEX warmed up! Its already above normal. For those who where thinking that the cold snap this winter was going to have any effect, think again.

Temporary cold has little effect on the massive oceans. Cool phase of the PDO has begun, and the El Nino has collapsed into a still-cooling La Nina along the entire US West Coast and down into South America. This might change Gulf SSTs eventually if the sub-tropical jet continues its southerly track along the Gulf of Mexico-to-Florida straights corridor.

In other words, the Pacific weather pattern which directed more snowstorms across the US this year has shifted even farther south with the onset of summer. If it remains to the south (which it won't continuously) will it direct storms out into the Atlantic basin?

In other news, looks like the top of the bent pipe on the riser, and something underneath the riser, have finally failed. Massive blowout from somewhere below the bent tube on camera. Not good at all...
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I've always wondered, if a storm survives the trek over Central America/Mexico, does it retain its name from the basin of origin? I know storms get new names when they deteriorate and regenerate, but what about if it stays above TS level?
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Re: Hurricane Preparedness.
Okay, I'm convinced that now's the time to take preparations seriously (I live on a barrier island along east central Florida's coast). So this weekend (starting today already), I've begun to sort through the stuff in my hurricane shelter (downstairs) in order to make room in case I need it. I know everyone says "evacuate;" however, I have too many pets to reasonably do this and this house is constructed with a shelter. Also, I'm pretty high up in some dunes with about an acre of oaks around me so do have some protection. Anyway, I am now putting things in order, will get some more plastic containers this weekend, and make sure that I have a couple of blue tarps, a couple rolls of duct tape, cleaning supplies, etc. and will be making up plastic, sealed boxes. One will have paper goods like paper towels, tp, and a medical kit, duct tape, cleaning supplies etc. go in another. One will be a dry clothing box. And one will be a food box. This will help to shorten my preparations and if and when a storm does arrive here. Also, being prepared myself means I'll have time to be sure all of my shutters get put up and I can also help my neighbors, including my 83-year-old mother who lives across the street! Nothing's perfect. We've got to take stock of what we have (and don't have) and work within the parameters. I'm probably two blocks from the ocean and the highest point around here. That kind of scares me but the house is heavy beam on top (first floor thirty feet over solid concrete structure below). I'm admittedly getting nervous, though, reading through the predictions for this season!
This is a good weekend to do it.
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Quoting FIU2010:
drak, are you expecting it to survive the track?
If 90E strengthens it will probably make it to the Caribbean where it can intensify further. Now if it stays weak it should go over Central America and dissipate due to obvious reasons. Following the Dvorak intensity chart 90E should need to strengthen to a 999 MB low (around 52 MPH) for it to make it to the Caribbean. Remember the stronger the higher chances it has on making it to the Caribbean.
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Quoting MiamiHurricanes09:
Further intensification is plausible but not to that extent. Due to the proximity to land I doubt 90E will surpass a 50 MPH system, much less hurricane status.


It is still early for "fast" intensification.. but I would not be suprised, the system is rather large, and it isn't THAT close to land "yet". It's getting more organized, once the sun goes down, that's when the convection will really begin to erupt over the core of the system (as many of these systems tend to do) and with an anticyclone over it, it should strengthen to the very list into a moderately strong tropical storm.. atleast that's my view on it, and the CMC kinda agrees (which is the model I am going with for now).
Member Since: April 17, 2010 Posts: 0 Comments: 1753
Quoting leo305:
Once 90E gets completely organized, it will erupt.. into a hurricane, if it doesn't hit land by then.

I wouldn't be surprised, its under the perfect conditions for intensification.
Further intensification is plausible but not to that extent. Due to the proximity to land I doubt 90E will surpass a 50 MPH system, much less hurricane status.
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565. Skyepony

I believe in that case LGEM (Logistic Growth Equation Model) is the intensity model, which at this time is using BAMM for track. If you compare LGEM and BAMM for errors, they are the same.
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Quoting Skyepony:
Drak & Chucktown..Here's your CMC & LGEM are 2 different models..if they were the same models the error would be the same..

Average Error (nm)
model Error Trend 24hr Error 48hr Error 72hr Error Day 4 Error Day 5 Error
CMC CONSTANT 157.4 -1 -1 -1 -1

LGEM DECREASING 120.7 184.8 194.2 -1 -1


I was saying that link you posted as the LGEM is the GGEM which is recognized as the CMC
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Quoting IKE:


12Z NOGAPS
Did you see it Ike?
Member Since: September 27, 2007 Posts: 1 Comments: 22618
Quoting scott39:
What does that mean?
Ok. At the moment 90E is in an area conducive for development because there is an anticyclone placed aloft. An anticyclone is pretty much ridging over a system that deflects wind shear thus making lowering it. If you look at satellite imagery you will notice convection is expanding outwards indicative of a strengthening system. And to answer you previous question, 90E will probably not make it to the SE US because steering will not allow for that. Regardless of having an anticyclone aloft 90E will likely not make it to the SE US.
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Here is video of whatever it was that happened to the ROV monitoring the Top Kill this morning... Link

(It is a link to download a 7.7mb video file with about 15 minutes of video.)

It looks like something exploded BEHIND the ROV, pushing it into the plume. Lots of debris floating around and falling from above for awhile after.
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Once 90E gets completely organized, it will erupt.. into a hurricane, if it doesn't hit land by then.

I wouldn't be surprised, its under the perfect conditions for intensification.
Member Since: April 17, 2010 Posts: 0 Comments: 1753
did someone ask for a vort map ok well here it is it's the same one that is used on crownweather.com
Link

Member Since: June 13, 2009 Posts: 2 Comments: 12716
565. Skyepony (Mod)
Drak & Chucktown..Here's your CMC & LGEM are 2 different models..if they were the same models the error would be the same..

Average Error (nm)
model Error Trend 24hr Error 48hr Error 72hr Error Day 4 Error Day 5 Error
CMC CONSTANT 157.4 -1 -1 -1 -1

LGEM DECREASING 120.7 184.8 194.2 -1 -1
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Quoting scott39:
What does that mean?


An anticyclone over a forming cyclone helps in outflow, allowing for faster intensification and resistance to shear
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Quoting FloridaTigers:
Can anyone post the vorticity maps?


Nope, just old guys...LOL

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Quoting leo305:


it has an anti cyclone on it..
What does that mean?
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Quoting MiamiHurricanes09:
Yup. Notice the below average equatorial Pacific and the above average Atlantic basin, mostly the African coast and the GOM.



Yikes. Not only has the GOM warmed up back to normal, but in some areas it is around 2 degrees Celsius above normal!!
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Quoting FloridaTigers:
Can anyone post the vorticity maps?
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Quoting scott39:
Is 90E even a threat to the SE USA if it goes in that direction? Seeing how wind shear will blow it apart?


it has an anti cyclone on it..
Member Since: April 17, 2010 Posts: 0 Comments: 1753

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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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