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 futuremet:


FIU2010, I advise you to be careful. There a lot of free translators on the Internet.


I think JFV/PresidentialElection/Weatherstudent/FIU2010 knows that. Anywho, how you been Juderson?
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Quoting PcolaDan:


Now THESE are funny. :)


1 zillion barrels of oil= GOM
Member Since: Posts: Comments:
1403. pottery
Quoting TexasGulf:


Pottery: I'm not meaning to correct you, but just to make an observation. Pure water does freeze at 0 degC or 32 degF only at standard atmospheric pressure. Water boils at 100 degC or 212 degF at standard atmospheric pressure.

Any impurities in the water can cause the boiling or freezing point to change. Salt water is a good example. Also, changes in atmospheric pressure cause boiling / freezing points to change. At high altitudes, with low atm pressure, water boils at a lower temperature. In a pressure cooker, at 10 psig for example, water boils at a higher temperature of around 218 degF.

The freezing temperature for pure water in the upper atmosphere is different from the freezing temperature at sea level.

Yep! I knew that. But it was a very general comparison of temps (or so I thought at the time) that we were having.
Member Since: Posts: Comments:
Quoting beell:
Some more useful conversions:

1 million phones = 1 megaphone
2000 mockingbirds = two kilomockingbirds
10 cards = 1 decacards
1 millionth of a fish = 1 microfiche
453.6 graham crackers = 1 pound cake
1 trillion pins = 1 terrapin
10 rations = 1 decoration
100 rations = 1 C-ration
10 millipedes = 1 centipede
3 1/3 tridents = 1 decadent
2 monograms = 1 diagram
8 nickels = 2 paradigms
2 wharves = 1 paradox


LOL very funny
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Quoting FIU2010:
you wish i lived in hialeah, child. also, never say never, when it comes to the field of tropical meteorology, sigh, so young, so much to learn. GET WITH THE PROGRAM, manito, some storms will always strong LCC then others, hence increasing their likelyhood of surviving, signifiantly. granted, that's not the case with all of them, of course.


Lets be honest: No one REALLY wants to live Hialeah. :)
Member Since: Posts: Comments:
The GFS long range is showing a storm in the GOM in about 10-12 days...
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Member Since: Posts: Comments:
Quoting beell:
Some more useful conversions:

1 million phones = 1 megaphone
2000 mockingbirds = two kilomockingbirds
10 cards = 1 decacards
1 millionth of a fish = 1 microfiche
453.6 graham crackers = 1 pound cake
1 trillion pins = 1 terrapin
10 rations = 1 decoration
100 rations = 1 C-ration
10 millipedes = 1 centipede
3 1/3 tridents = 1 decadent
2 monograms = 1 diagram
8 nickels = 2 paradigms
2 wharves = 1 paradox


Now THESE are funny. :)
Member Since: August 22, 2008 Posts: 12 Comments: 6010
1397. Ossqss
On the oil leak, where is the huge clean up effort on the water? Where is it???/?????//?????

Politics over environmental action is BS folks. BS.............. how many days and not much of anything there........
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Quoting FIU2010:



ha, dios mio, mira quien habla, CANDELA, en fin, i'll have my forecast for the cane season coming up, available by early next week, y'all, im almost done with it, :).


FIU2010, I advise you to be careful. There a lot of free translators on the Internet.
Member Since: Posts: Comments:
Quoting Bordonaro:


They claim they will not know for sure until Sunday.

I say it's about time use a MAJOR conventional warhead to blow that BOP out and seal off the well, period. Like some of the USAF Saddam Bunker Buster bombs.


Mize well split the earth in half. LOL
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1394. pottery
Quoting Bordonaro:


They claim they will not know for sure until Sunday.

I say it's about time use a MAJOR conventional warhead to blow that BOP out and seal off the well, period. Like some of the USAF Saddam Bunker Buster bombs.

LOL, Make sure that all the surfers know about it first. So they can catch the wave all the way to Kansas.
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Co -Cirrus overspread
CDO - Central dense Overcast
OBA - outer band area
ECT - embedded cloudtops

Member Since: Posts: Comments:
1392. EricSFL
Quoting beell:
Some more useful conversions:

1 million phones = 1 megaphone
2000 mockingbirds = two kilomockingbirds
10 cards = 1 decacards
1 millionth of a fish = 1 microfiche
453.6 graham crackers = 1 pound cake
1 trillion pins = 1 terrapin
10 rations = 1 decoration
100 rations = 1 C-ration
10 millipedes = 1 centipede
3 1/3 tridents = 1 decadent
2 monograms = 1 diagram
8 nickels = 2 paradigms
2 wharves = 1 paradox


lol
Member Since: Posts: Comments:
Quoting pottery:

OH!!!
So sorry, I did not see the original question.
My eyes, you know, old age and stuff...


It's the "and stuff" that gets us though. ;)
Member Since: August 22, 2008 Posts: 12 Comments: 6010
1390. KEEPEROFTHEGATE (Mod)
Quoting Funkadelic:


Sentence in Bold does not make sense kiddo:)
none of it really does
Member Since: July 15, 2006 Posts: 174 Comments: 54450
1388. beell
Some more useful conversions:

1 million phones = 1 megaphone
2000 mockingbirds = two kilomockingbirds
10 cards = 1 decacards
1 millionth of a fish = 1 microfiche
453.6 graham crackers = 1 pound cake
1 trillion pins = 1 terrapin
10 rations = 1 decoration
100 rations = 1 C-ration
10 millipedes = 1 centipede
3 1/3 tridents = 1 decadent
2 monograms = 1 diagram
8 nickels = 2 paradigms
2 wharves = 1 paradox
Member Since: Posts: Comments:
Quoting pottery:

Water freezes at 32f=0c


Pottery: I'm not meaning to correct you, but just to make an observation. Pure water does freeze at 0 degC or 32 degF only at standard atmospheric pressure. Water boils at 100 degC or 212 degF at standard atmospheric pressure.

Any impurities in the water can cause the boiling or freezing point to change. Salt water is a good example. Also, changes in atmospheric pressure cause boiling / freezing points to change. At high altitudes, with low atm pressure, water boils at a lower temperature. In a pressure cooker, at 10 psig for example, water boils at a higher temperature of around 218 degF.

The freezing temperature for pure water in the upper atmosphere is different from the freezing temperature at sea level.
Member Since: Posts: Comments:
Quoting TampaSpin:
I have been away all day ....has Top Kill worked at all on the leak?


They claim they will not know for sure until Sunday.

I say it's about time use a MAJOR conventional warhead to blow that BOP out and seal off the well, period. Like some of the USAF Saddam Bunker Buster bombs.
Member Since: Posts: Comments:
1385. pottery
Quoting TampaSpin:
I have been away all day ....has Top Kill worked at all on the leak?

Does not seem so...
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The 0Z gfs is running if no one knew
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Quoting pottery:

OH!!!
So sorry, I did not see the original question.
My eyes, you know, old age and stuff...

Don't feel bad, I am 12 yrs younger than you are and the "old age" thing is real sneaky. God has a cool sense of humor :O)!
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I have been away all day ....has Top Kill worked at all on the leak?
Member Since: Posts: Comments:
Quoting pottery:

LOL, you are mixing up "temp" with "anomalous temp" surely?
Believe me.--- 32f is 0c
0f is -17.8c
100f is 37.8c
etc etc


Actually, that's completely correct. I see what you guys are saying now. My bad.
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1380. Motttt
I think I will go with the average filter for the start
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A lil' math confusion :o)!!
The SST are 0.2C higher than normal.

The SST are 0.326F higher than normal.

0.2C air temp= 32.6F air temp.

Have a nice day :O)!!!
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1378. Ossqss
1371. FIU2010

Hey, how is your uncle doing living in the Dry Tortugas national park as you told us last year ? :)

Where exactly is he anyhow ?

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1377. pottery
Quoting Bordonaro:

KoritheMan asked what 0.2 C temp difference would be in F.

A 0.2C temp difference= a 0.326F temp difference.

The 0.2C actual temp= 32.6F actual temp

OH!!!
So sorry, I did not see the original question.
My eyes, you know, old age and stuff...
Member Since: Posts: Comments:
1376. pottery
Quoting KoritheMan:


In both your and 13's defense, a Celsius to Fahrenheit translator that I recently pulled up via a quick Google search does indeed confirm that 0.2C = 32.36F, but that seems a little off, doesn't it?

I mean, there are a lot of 0.2C SST anomalies in the Caribbean at present time. Does that mean that SSTs in the area are running 32F above average?

LOL, you are mixing up "temp" with "anomalous temp" surely?
Believe me.--- 32f is 0c
0f is -17.8c
100f is 37.8c
etc etc
Member Since: Posts: Comments:
Quoting KoritheMan:


In both your and 13's defense, a Celsius to Fahrenheit translator that I recently pulled up via a quick Google search does indeed confirm that 0.2C = 32.36F, but that seems a little off, doesn't it?

I mean, there are a lot of 0.2C SST anomalies in the Caribbean at present time. Does that mean that SSTs in the area are running 32F above average?

LOL.

Try the difference between 2 conversions 0.2 degrees C apart.
(I know you guys know this)
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1374. EricSFL
Member Since: Posts: Comments:
Quoting pottery:

WHA???

KoritheMan asked what 0.2 C temp difference would be in F.

A 0.2C temp difference= a 0.326F temp difference.

The 0.2C actual temp= 32.6F actual temp
Member Since: Posts: Comments:
1370. EricSFL
Quoting FIU2010:
you wish i lived in hialeah, child. also, never say never, when it comes to the field of tropical meteorology, sigh, so young, so much to learn. GET WITH THE PROGRAM, manito, some storms will always strong LCC then others, hence increasing their likelyhood of surviving, signifiantly. granted, that's not the case with all of them, of course.


But FIU2010, yesterday when you mentioned it was "pouring" the radar only showed a storm located over Hialeah / Miami Gardens.
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Quoting Bordonaro:

Per the earlier question, 0.2C= 0.326F


That seems more plausible.
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X-Trap pointed NE, here he comes.

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Scientists say Katla may erupt soon.
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Quoting stormwatcherCI:
.2 degrees Celsius = 32.36 degrees Fahrenheit


In both your and 13's defense, a Celsius to Fahrenheit translator that I recently pulled up via a quick Google search does indeed confirm that 0.2C = 32.36F, but that seems a little off, doesn't it?

I mean, there are a lot of 0.2C SST anomalies in the Caribbean at present time. Does that mean that SSTs in the area are running 32F above average?
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1365. pottery
Quoting Bordonaro:

Per the earlier question, 0.2C= 0.326F

WHA???
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Quoting pottery:

Sometimes the statements made here are downright stupid.
Amen . I think they pull them out of left field.
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Quoting pottery:

Water freezes at 32f=0c

Per the earlier question, 0.2C= 0.326F
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1362. KEEPEROFTHEGATE (Mod)
Quoting EricSFL:
Hello "oil slick man".
hello
Member Since: July 15, 2006 Posts: 174 Comments: 54450
Quoting pottery:

Water freezes at 32f=0c


I know I was verifying that his conversion was correct, not the original info.

That is what I thought was being questioned
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1360. pottery
Quoting FIU2010:


agreed, pat, thanks! this blog should have an age limit, to prevent little boys from blogging on here, after hours.

Sometimes the statements made here are downright stupid.
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Quoting MiamiHurricanes09:
Way way off. It's about 0.5˚F
.2 degrees Celsius = 32.36 degrees Fahrenheit
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Quoting KoritheMan:


Yeah. Case in point is 2004's Charley.
Yeah charley had me scared we werent prepared (not my fault ) and right when we finished putting the last board on the house the storm turned and we know what happened i live in odessa just north of tampa so that was a crazy season 2004
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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.