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 atmoaggie:

I wonder how well a UPS can handle either generator or inverter...some of those can provide plenty of conditioned power to run most any home electronics.
(I know we have a room full of UPSs charged by generator at my office, but possibly involves equipment to condition the generator power? likely beyond what anyone one might try at home due to equipment cost)
A natural gas generator might be okay, dunno. One of my neighbors got a really good deal on one of those last year. Runs quiet, too.

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755. IKE
Look at the vorticity...

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Quoting Hurricanes101:
Ok here is an intriguing question for you guys, lets see how the voting goes.

Note: I am not saying either of these three things will occur this season, but with the numbers predicted being higher than they ever have been, I am curious as to which of these extremes is more likely.

Which is most likely to occur during the 2010 Hurricane Season?

A) Category 5 landfall in the United States
B) 2010 being more active than 2005
C) A storm during the 2010 Season will become the most intense storm in Atlantic Basin History (881mb or lower)?

I say either A or C...My percentages of possibility A >> 30% C >> 70% JMO.
Member Since: Posts: Comments:
753. IKE
120 hour GFS 18Z....

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Quoting wunderkidcayman:
LOL kmanislander ok let me clearify lower than 13 000 and 8000 feet



I did research a while back and I believe Guatemala has volcanoes there bigger than 13,000ft.

Looks like the storm will get its name and hit land and nothing more. No redeveloping to hit Florida. Albeit, moisture increase there is a possibility from this system. {Just what im thinking at the moment}...
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Quoting MiamiHurricanes09:
GFS 18z 108 Hours.
Well it tracks it like the cmc but idont think it will be anything tropical probably a lot of rain for some in south florida
Member Since: April 8, 2010 Posts: 15 Comments: 2572
Quoting Patrap:


BP is steering it I hear Ike.

Hey Pat, I had an idea. Maybe we go could from one friend of the region to another in naming rights?

How does the BP Sugar Bowl sound?
(Is Allstate, currently, for you out of towners)
*snark*
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Quoting atmoaggie:

I wonder how well a UPS can handle either generator or inverter...some of those can provide plenty of conditioned power to run most any home electronics.
(I know we have a room full of UPSs charged by generator at my office, but possibly involves equipment to condition the generator power? likely beyond what anyone one might try at home due to equipment cost)


They work fine...
Member Since: Posts: Comments:
747. IKE
Maybe the CMC was on to something with track on 90E....

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Quoting Hurricanes101:
Ok here is an intriguing question for you guys, lets see how the voting goes.

Note: I am not saying either of these three things will occur this season, but with the numbers predicted being higher than they ever have been, I am curious as to which of these extremes is more likely.

Which is most likely to occur during the 2010 Hurricane Season?

A) Category 5 landfall in the United States
B) 2010 being more active than 2005
C) A storm during the 2010 Season will become the most intense storm in Atlantic Basin History (881mb or lower)?


I say A
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Pat, tell them to steer it somewhere else. They have given us enough to worry about for awhile.
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Quoting Chicklit:

Not a good idea to run electronic equipment, including tv, off a generator. You'll liable to ruin your equipment. Better to use battery power for that, if you've got a laptop or use your phone.

I wonder how well a UPS can handle either generator or inverter...some of those can provide plenty of conditioned power to run most any home electronics.
(I know we have a room full of UPSs charged by generator at my office, but possibly involves equipment to condition the generator power? likely beyond what anyone one might try at home due to equipment cost)
Member Since: Posts: Comments:
743. JLPR
Quoting Hurricanes101:
Ok here is an intriguing question for you guys, lets see how the voting goes.

Note: I am not saying either of these three things will occur this season, but with the numbers predicted being higher than they ever have been, I am curious as to which of these extremes is more likely.

Which is most likely to occur during the 2010 Hurricane Season?

A) Category 5 landfall in the United States
B) 2010 being more active than 2005
C) A storm during the 2010 Season will become the most intense storm in Atlantic Basin History (881mb or lower)?


I think C
Member Since: September 4, 2007 Posts: 36 Comments: 5223
Quoting IKE:


Looks like what's left of 90E heads for the SE GOM in 90 hours on the GFS. Not convinced it's not partially convective feedback.
GFS 18z 108 Hours.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting IKE:


Looks like what's left of 90E heads for the SE GOM in 90 hours on the GFS. Not convinced it's not some convective feedback.


BP is steering it I hear Ike.
Member Since: July 3, 2005 Posts: 426 Comments: 129093
740. IKE
Quoting alexhurricane1991:
Nothing out there to worry about through 72 hours.


Looks like what's left of 90E heads for the SE GOM in 90 hours on the GFS. Not convinced it's not partially convective feedback.
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Well, I am out for now. Will check in later.
Member Since: August 19, 2006 Posts: 0 Comments: 15890
someone turned the feed downlink OFF to 90E here
Member Since: July 3, 2005 Posts: 426 Comments: 129093
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Quoting IKE:
18Z GFS through 72 hours...
Nothing out there to worry about through 72 hours.
Member Since: April 8, 2010 Posts: 15 Comments: 2572
How does that guy keep getting off my Ignore list?

**poof**
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90E Model Plots
Member Since: July 3, 2005 Posts: 426 Comments: 129093
Quoting xcool:
LOOK AT 90E OHWOW

Up to 70% for tropical depression within 48 hrs. (from 60% last night).
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Jamaica
Met service website

May 28, 2010 at 4:00 p.m.

LOCAL WEATHER FORECAST

SIGNIFICANT FEATURES… Area of Low Pressure and Trough over Jamaica.

Comment…
The Trough over the island will remain until Monday while the Area of
Low Pressure just southwest of the island is likely to persist until Sunday.

24-HOURS FORECAST
Tonight…Lingering showers.
Tomorrow… Expect scattered afternoon showers and thunderstorms across most parishes.

3-DAYS FORECAST (starting tomorrow)
Sun… Periods of showers and thunderstorms, especially during the afternoon.
Mon… Scattered showers with isolated thunderstorms over central and western parishes.
Tue… Partly cloudy day. A few afternoon showers are expected over inland areas and south-western parishes.

Regionally… An Area of Low Pressure is southwest of the island, while High Pressure Ridges are to the east and west of the Low Pessure and Trough.

rar
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731. IKE
18Z GFS through 72 hours...
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Quoting FIU2010:
Guajiro, que bola?


You have Ebola?
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Bp is no longer in charge ,the president made that VERY CLEAR yesterday!!!!Anything being done now is with his approval only!!He said they have been in charge from day one.Nothing has been done without his approval!!!!Listen to his press conference.
Member Since: September 18, 2006 Posts: 0 Comments: 1289
Quoting wunderkidcayman:
LOL kmanislander ok let me clearify lower than 13 000 and 8000 feet


Sorry, couldn't resist it LOL.

I think the point has been made that a passage over Guatemala is nothing like the low lying marshland in, say, coastal Nicaragua that can help a system maintain itself quite well while traversing land. We saw this late last year in October where a storm ran inland Nicaragua for over a day and came offshore still as a TS.
Member Since: August 19, 2006 Posts: 0 Comments: 15890
21:45 UTC - 5:45 UTC
Member Since: September 2, 2009 Posts: 130 Comments: 21194
726. xcool
LOOK AT 90E OHWOW
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LOL kmanislander ok let me clearify lower than 13 000 and 8000 feet
Member Since: June 13, 2009 Posts: 2 Comments: 12525
Quoting kmanislander:


You're right,some parts are over 13,000 feet up
Yep i have serious doubts that 90E can redevelop in the caribbean it could still happen but im not seeing it to little time to restructure itself.
Member Since: April 8, 2010 Posts: 15 Comments: 2572
Well, let's see how 90E gets on in the Pacific before we worry about it getting into the Caribbean. Many models have called for energy from 90E to make it over during the past few days and then ramp up. It just has not played out that way to date.
Member Since: August 19, 2006 Posts: 0 Comments: 15890
Quoting kmanislander:


You're right,some parts are over 13,000 feet up


lol!!
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Quoting Hurricanes101:
Ok here is an intriguing question for you guys, lets see how the voting goes.

Note: I am not saying either of these three things will occur this season, but with the numbers predicted being higher than they ever have been, I am curious as to which of these extremes is more likely.

Which is most likely to occur during the 2010 Hurricane Season?

A) Category 5 landfall in the United States
B) 2010 being more active than 2005
C) A storm during the 2010 Season will become the most intense storm in Atlantic Basin History (881mb or lower)?

I vote for B
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XtremeStormJunkies Update:

The full-scale portable power test of the live severe webcam is now at 7 hours with no interruption in any service.

All bluetooth devices, which are operating on their own, internal batteries are still functioning well.

The webcam system (computer, cell phone, and wireless 3G broadband card) are still fully operational and running off the "main batt."

You can see the progress of this full-scale portable power test by going to our media call-out URL of 7674u.com

We're now getting into serious insanity! My little bluetooth is still streaming with the video after 7 hours!
Member Since: Posts: Comments:
Quoting Hurricanes101:
Ok here is an intriguing question for you guys, lets see how the voting goes.

Note: I am not saying either of these three things will occur this season, but with the numbers predicted being higher than they ever have been, I am curious as to which of these extremes is more likely.

Which is most likely to occur during the 2010 Hurricane Season?

A) Category 5 landfall in the United States
B) 2010 being more active than 2005
C) A storm during the 2010 Season will become the most intense storm in Atlantic Basin History (881mb or lower)?
A. But C seems probable.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting wunderkidcayman:
come on guys I am sure that not everywhere in Guatemala is 8000 feet up


You're right,some parts are over 13,000 feet up
Member Since: August 19, 2006 Posts: 0 Comments: 15890
Quoting alexhurricane1991:
If i had to choose it would be A but i dont think any of these will happen.


I dont think it is very likely we will see any of these either, but if I had to choose, I would actually pick C. With the record SSTs and TCHP going on, I dont think it is out of the realm for us to see a storm surpass Wilma as the most intense
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Quoting Hurricanes101:
Ok here is an intriguing question for you guys, lets see how the voting goes.

Note: I am not saying either of these three things will occur this season, but with the numbers predicted being higher than they ever have been, I am curious as to which of these extremes is more likely.

Which is most likely to occur during the 2010 Hurricane Season?

A) Category 5 landfall in the United States
B) 2010 being more active than 2005
C) A storm during the 2010 Season will become the most intense storm in Atlantic Basin History (881mb or lower)?
If i had to choose it would be A but i dont think any of these will happen.
Member Since: April 8, 2010 Posts: 15 Comments: 2572
Orca, what's up?
Member Since: Posts: Comments:
Ok here is an intriguing question for you guys, lets see how the voting goes.

Note: I am not saying either of these three things will occur this season, but with the numbers predicted being higher than they ever have been, I am curious as to which of these extremes is more likely.

Which is most likely to occur during the 2010 Hurricane Season?

A) Category 5 landfall in the United States
B) 2010 being more active than 2005
C) A storm during the 2010 Season will become the most intense storm in Atlantic Basin History (881mb or lower)?
Member Since: Posts: Comments:
Hey Oz, I just checked out your live feed. You sound a little digitized and keep saying the same thing over and over - LOL

It does look and sound good, and for over 6 hours, wow. BTW, still working on that suit ? :)



L8R >>
Member Since: June 12, 2005 Posts: 6 Comments: 8186
come on guys I am sure that not everywhere in Guatemala is 8000 feet up
Member Since: June 13, 2009 Posts: 2 Comments: 12525
Member Since: September 2, 2009 Posts: 130 Comments: 21194

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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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