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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2257. IKE
12Z CMC
Member Since: June 9, 2005 Posts: 23 Comments: 37858
2256. Patrap
This ULL may have a influence on Agatha Ike..



Member Since: Posts: Comments:
Quoting lavinia:
How close is Agatha going to pass by Pacaya? Will the volcano have any effect on it?


- Look at figure 3 on my blog.

- The volcano by itself will not have any impact on Agatha. Rather the presence of terrain will weaken Agatha rapidly once ashore.

- The rains from the tropical storm would mix with ash to create mud leading to mudslides. On the upside, the rains have helped cleaned the ash off the coffee crops there.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
2253. Levi32
The MSLP anomaly profile over the past 7 days has been becoming reminiscent of what the rest of the summer will likely be like, with lower than normal pressures across the entire southwestern Atlantic south of 30N, with higher than normal pressures building across the equatorial Pacific. This is showing the tendency for heat to build up in the Atlantic more than any other basin in the northern Hemisphere, and with our basin being the logical focus-point for global heat this year, it follows that we will likely see a bursting of tropical activity as a response.

Member Since: Posts: Comments:
2251. IKE
BP Press Conference now.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
2250. Patrap
Member Since: Posts: Comments:
2249. IKE
Quoting Patrap:
233 iz coming n out in a moment




That includes me. Thunderstorm and 68 degrees here now.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
2248. Patrap
233 iz coming out in a moment


Member Since: Posts: Comments:
2247. IKE
Top Kill Likely a Failure

From the article....

"I'm now hearing that BP determined the top kill failure sometime in the last 24 hours, but rather than announce it, have decided to just keep pumping until the next alternative is decided, either the LMRP (lower marine riser cap) cap to bring flow to the surface, or removing the LMRP and landing a new BOP on top of the failed one."
Member Since: June 9, 2005 Posts: 23 Comments: 37858
2246. Patrap
A Severe T-storm watch was just posted on the NOAA Alert Radio


Graphic to follow.
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2245. lavinia
How close is Agatha going to pass by Pacaya? Will the volcano have any effect on it?
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Landing through...

..ashfall in Guatemala
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2243. JRRP
Member Since: Posts: Comments:
2242. Patrap
Quoting nocaneindy:


I tell ya Pat, hearing qoutes like that from these BP fools just gets me madder by the second.
I'd like to wave a lot more than a finger at em, but out of fear of banishment, I'll just leave it at that.
Thanks for all the postings you have done for now more than a month on this travesty.
I for one really appreciate the info you've provided.


Thanx..its been my xtreme pleasure to help keep them in the proper Light.


Tune in to Dr. Masters new show for more on Oil and Hurricanes.


Member Since: Posts: Comments:
Quoting wunderkidcayman:
ok guys let get something clear I highly doubt that TS AGATHA when it crosses over that it will go to Florida looking at the steering maps it looks like the obvious track would be the Caribbean don't believe me well look then



LENNY-like track across the entire caribbean?
Member Since: Posts: Comments:
Quoting Patrap:
OH he didnt...

"wagging finger Like a Momma"


British Petroleum rep Randy Prescott's
quote: "Louisiana isn't the only place that has shrimp."




I tell ya Pat, hearing qoutes like that from these BP fools just gets me madder by the second.
I'd like to wave a lot more than a finger at em, but out of fear of banishment, I'll just leave it at that.
Thanks for all the postings you have done for now more than a month on this travesty.
I for one really appreciate the info you've provided.
Member Since: Posts: Comments:
Quoting pottery:

No. It simply will not open. No 'install this' or anything.


Hello Pottery! Brother, can you spare a raindrop??

BP is a major corporation, who totally misjudged the Deepwater Horizon well and its problems. I say we string them up and feed them to the sharks :o)!!
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2238. Motttt
This Is what Kent Wells from BP says what they will be doing on the well.
Link
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2237. pottery
Quoting will45:



Ok i had prob with it in a couple of browsers but firefox opens it for me

I may need to change from Safari then LOL.
Thanks for the try.
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Quoting Patrap:
OH he didnt...

"wagging finger Like a Momma"


British Petroleum rep Randy Prescott's
quote: "Louisiana isn't the only place that has shrimp."




This message brought to you by the Georgia Shrimper's Association...

In all seriousness, though, the impacts on the Gulf fishery are a tragedy that i would never wish on anybody.
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2235. Levi32
Quoting Weather456:


ADT and EDT are both -4 GMT during daylight savings.

When daylight savings end, the US goes back to standard - EST which is -5 GMT. We do not practice daylight savings so we are always -4 GMT. So there is a 6 month period between Fall and Spring when I'm 1
hr ahead of the US.


Oh ok, thanks.
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2234. Levi32
Quoting FIU2010:


thanks, so it'll a decaying one instead, correct?


If there is anything to decay at all, yes.
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2233. pottery
Quoting Patrap:


The Brits were never known for their culinary palate

Oh, I dont know. What about bread pudding. And porridge. And, er, well never mind...
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2232. will45
Quoting pottery:

No. It simply will not open. No 'install this' or anything.



Ok i had prob with it in a couple of browsers but firefox opens it for me
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2231. KEEPEROFTHEGATE (Mod)
Member Since: Posts: Comments:
Quoting Levi32:


Right....Antilles. Are you guys ADT? 1 hour later than EDT?


ADT and EDT are both -4 GMT during daylight savings.

When daylight savings end, the US goes back to standard - EST which is -5 GMT. We do not practice daylight savings so we are always -4 GMT. So there is a 6 month period between Fall and Spring when I'm 1
hr ahead of the US.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Does anybody recommend Google Earth for tracking storms?
Member Since: Posts: Comments:
TS force winds are about 38 miles from the coast



Member Since: July 24, 2005 Posts: 407 Comments: 19076
2227. Patrap
Quoting gulfcoastdweller:


he must be used to that import crap that comes from China


The Brits were never known for their culinary palate
Member Since: Posts: Comments:
2226. pottery
Quoting will45:
Link


You cant get thatone potter?

No. It simply will not open. No 'install this' or anything.
Member Since: Posts: Comments:
2225. Drakoen
I see the EPAC has Agatha steering currents should take here towards the ENE and she should weaken to a TD. How fast she weakens overland will be critical to how far east she can go as the lower to mid level steering currents will want to take her more northward around 48 hours.
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2223. Patrap
Quoting msgambler:
crab or gator Pat?


both,...
Member Since: Posts: Comments:
Quoting IKE:
From the NY Times...Latest Attempt by BP to Plug Oil Leak in Gulf of Mexico Fails

Just posted 10 minutes ago.

From the article....

"The technician working on the project said Saturday pumping has again been halted and a review of the data so far is underway after engineers failed again to restrict or plug the well.

Right now, I would not be optimistic,the technician, who spoke on condition of anonymity because he is not authorized to speak publicly about the effort. But he added, that if another attempt at the junk shot were to succeed, that would turn things around.

BP said Saturday it would not comment on the technician assertions. Officials have said they will continue the process into Sunday before they declare it a success or failure."


We're doomed :-(
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well
BP is damned sure
not the only place
with petroleum
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2220. KEEPEROFTHEGATE (Mod)
Quoting IKE:
Actor Dennis Hopper Dies at Age 74
two now they come in threes maybe one more yet
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2217. Patrap
Member Since: Posts: Comments:
2216. pottery
Quoting SavannahStorm:
Someone mentioned that they are now considering a "pipe-pinching" procedure when all other options are off the table. It would involve carefully placed explosive charges destroying the blowout preventor and sealing the pipe. BP is apparently leaving this as a last option because it would mean the Deepwater Horizon project would be permanently lost and they would have to start from scratch to get any more oil from the deposit. So once again, it comes down to $$, because BP doesn't want to lose a well they can still extract oil from.

I would think that, all things considered, to try to seal the pipe with explosive is much too risky.
As it stands now, SOME of the oil and gas is leaking out.
If you manage to destroy the BOP and not seal the pipe, the crap will really start...
Member Since: Posts: Comments:
Quoting Asta:

They were all there its true Patrap..
but he only mentioned beaches.
He did not mention wetlands,
and he did not even set foot or visit the marshes. The photo op of him picking up a quarter sized tarball on a cleaned beach was, I think, extremely misleading.


The "Cult of Personality" we have built around our presidents is unfortunate IMACO (arrogant and conceited opinion). POTUS is an executive not a king or god. Thank goodness. As such Obama has done about all he can: put the best folks he's got in charge, authorize overtime and make the best noises he can to keep up the moral. He actually had more options in Hatti. Only way he can send in Federal Troops is if total break down of law and order. ie Posse Comitatus Act (Bp and BMM might qualify but kind of hard to invade) Doesn't leave much more he can do except photo ops.
Member Since: Posts: Comments:
crab or gator Pat?
Member Since: February 27, 2010 Posts: 0 Comments: 1125
2213. IKE
Actor Dennis Hopper Dies at Age 74
Member Since: June 9, 2005 Posts: 23 Comments: 37858
2212. Patrap
I sense his Immediate departure.

And if pops up here...well, he may become crab bait.

Member Since: Posts: Comments:
2211. Patrap
OH he didnt...

"wagging finger Like a Momma"


British Petroleum rep Randy Prescott's
quote: "Louisiana isn't the only place that has shrimp."


Member Since: Posts: Comments:
2210. Levi32
Quoting FIU2010:
afternoon levi. well ag be a conus threater?


While its remnants may get into the Gulf of Mexico at some point, it would not be a strengthening tropical system due to the subtropical jet screaming over the Gulf of Mexico.
Member Since: Posts: Comments:
2209. will45
Link


You cant get thatone potter?
Member Since: Posts: Comments:
2208. Levi32
Quoting Weather456:


Good Afternoon


Right....Antilles. Are you guys ADT? 1 hour later than EDT?
Member Since: Posts: Comments:

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About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.