Clouds, unstable Loop Current making oil spill prediction difficult

By: Dr. Jeff Masters , 8:48 PM GMT on May 18, 2010

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It's cloudy over the Gulf of Mexico today, so it is difficult to tell how far into the Loop Current the Deepwater Horizon oil has penetrated using visible satellite imagery. Satellite imagery yesterday from NASA's MODIS instrument confirmed that a tongue of oil moved southeast from the Deepwater Horizon oil spill and entered the Gulf of Mexico's Loop Current. However, Synthetic Aperture Radar imagery from the European Envisat satellite posted at ROFFS Ocean Forecasting Service shows that while some of the tongue of oil that entered the Loop Current appears to be circulating southwards towards the Florida Keys, perhaps 80% of the oil in this tongue is caught in a counter-clockwise circulating eddy along the north side of the Loop Current. This oil may eventually circulate around and enter the Loop Current, but not for at least three days.


Figure 1. Oil spill forecast for this Thursday night as simulated by the 6pm EDT Monday May 17 runs of the Navy Gulf of Mexico HYCOM nowcast/forecast system and the Global HYCOM + NCODA Analysis from the HYCOM Consortium. See the University of South Florida Ocean Circulation Group website for more information. There are considerable differences between the two models, due in part to the fact that they have much different depictions of the sea surface temperatures (SSTs) and ocean currents at the beginning of their runs. The warm Loop Current is visible as the red colors of the SST field that form a heart-shaped area in the Gulf.

How long will it be until oil reaches the Keys?
Once oil gets into the Loop Current, the 1 - 2 mph speed of the current should allow the oil to travel the 500 miles to the Florida Keys in 5 - 10 days. Portions of the Loop Current flow at speed up to 4 mph, so the fastest transport could be 4 - 5 days.

How much oil has made it into the Loop Current?
According to the latest trajectory forecasts from NOAA, the tongue of oil flowing southwards has, at most, "light" concentrations. The oil will grow more dilute as it travels the 500 miles to the Florida Keys, and most of the oil appears to be caught in a smaller counter-clockwise rotating eddy on the north side of the Loop Current. My present expectation is that the oil entering the Loop Current this week will cause only minor problems in the Keys next week. However, there is a lot of uncertainty regarding how much oil will get to the Keys, and we cannot rule out the possibility of an ecological disaster in the fragile Keys ecosystem.

How is the Loop Current changing?
The Loop Current has been highly chaotic and unstable over the past week, making it difficult to predict how the ocean currents near the spill will behave. According to ROFFS Ocean Fishing Service, which has done a tremendous job tracking the spill, the Loop Current surged 7 - 10 miles northward Sunday and Monday. The Loop Current has gotten more contorted since Friday, and may be ready to cut off into a clockwise-rotating Loop Current Eddy. This process occurs every 6 - 11 months, with the clockwise-rotating ring of water slowly drifting west-southwest towards Texas. The last eddy broke off ten months ago, so the Loop Current is due to shed another eddy in the next few months. The latest 1-month forecast from the U.S. Navy does not predict an eddy forming, but these forecasts are not very reliable. If a Loop Current Eddy does break off, oil getting entrained into it might orbit the center of the Gulf of Mexico for many months inside the eddy. However, this eddy will probably reattach and detach from the main Loop Current flow for at least a month following when it breaks off, so oil will continue to flow through the Keys during this initial month.

When will the flow of oil into the Loop Current shut off?
Winds over the oil spill location are expected to be light and onshore at 5 - 10 knots through Saturday. This means that the chaotic contortions of the Loop Current will primarily control how much oil gets into it, making it difficult to predict when the flow will shut off. The long range (and thus unreliable) forecast for next week from the GFS model calls for a continuation of light winds over the eastern Gulf of Mexico. Thus, the flow of oil into the Loop Current could occur intermittently for several weeks.

Who besides the Keys are at risk next week from the Loop Current oil?
As I discussed in an earlier post, the coast of Southwest Florida from Tampa Bay to the Everglades is a "Forbidden Zone" for surface-based transport of ocean water to the coast, and is probably not at risk from this week's Loop Current oil. The northwest coast of Cuba east of Havana and the coast of Southeast Florida from the Keys to West Palm Beach are at the most risk. The western shores of the western-most Bahama Islands and the U.S. coast north of West Palm Beach northwards to Cape Hatteras are at slight risk. It would likely take ocean eddies 2 - 9 weeks to transport the oil to these locations, and the oil would probably be so dilute that ecosystem damage would probably be minor, at most. At this point, I see no reason for cancellation of vacation plans to any of the beach areas that may potentially be affected by the oil.

What is happening to the plumes of oil at depth?
Two research missions over the past week have detected substantial plumes of oil at depth, moving to the southwest. The deepest of the these plumes, near the site of the blowout at 5,000 feet depth, is in a region of slow ocean currents and has not moved much. At depths closer to the surface, the currents get stronger, and oil within a few hundred feet of the surface--if there is any--could potentially have been dragged into the Loop Current. At this point, we don't have a very good picture of how much oil is at depth and where it might be headed.

Oil spill resources
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
HYCOM ocean current forecasts from LSU

The tropics
For those of you interested in a detailed look at the early season tropical weather outlook, consult the excellent wunderblogs of StormW and Weather456, who are now featured bloggers for the coming hurricane season. We have some models predicting a possible subtropical storm off the U.S. East coast next week, but this does not appear to be a significant concern for land areas at this time. More concerning is the possibility that an area of disturbed weather will develop across the Western Caribbean late next week. While wind shear will likely keep anything in the Western Caribbean from developing, several models are predicting that this disturbance may bring major flooding rains to earthquake-ravaged Haiti late next week.

I'll be back with a new post Wednesday afternoon.

Jeff Masters

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Quoting StormW:
Good evening!


evening SW
Member Since: July 24, 2005 Posts: 407 Comments: 19076
119. IKE
18Z GFS through 138 hours.
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Post 109.
Now look again at the video earlier, of the leak at the top of the BOP.
This image gives the video some scale....the one on the video is like this one. Massive.
Member Since: October 24, 2005 Posts: 0 Comments: 24307
Hi StormW!
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My nomination for understatement of the year :)

Officials say the oil spill has so far had only a small pollution impact on the shoreline and wildlife along the Gulf Coast, but oil debris and tar balls have been reported in Louisiana, Alabama and Mississippi. Miles (kilometers) of protective booms are being used to try to defend the shore.

BP Chief Executive Tony Hayward was quoted by Sky News as saying he believed the ecological impact from the spill would be light. "I think the environmental impact of this disaster is likely to have been very, very modest," he said.


Link to full story
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The causeway Bridge shows up well in the Smooth Mode as the Tstorms rumble.

Member Since: July 3, 2005 Posts: 423 Comments: 128240
tornadodude is with practically every other storm chaser on the planet...chasing the Dalhart, TX cell. Timmer is there...but our young man correctly predicted Dalhart yesterday!

WTG t-dude!!!

Stay safe and good luck!
Member Since: August 26, 2006 Posts: 10 Comments: 3683
Quoting Ossqss:
Gheeze! WTH

Scientists, feds at odds over oil spill tracking model
Posted: May 18, 2010 - 4:37pm

I keep seeing vague references to a 10X3 mile 'submerged' area of oil, 300 feet thick.
But in each article (this one included) there lacks any real information on it.
Where is it?
What currents are affecting it?
How dense is it?
A research vessel has been testing for it. Have they not got some ideas?
Member Since: October 24, 2005 Posts: 0 Comments: 24307
Quoting Patrap:
Big Ol Gust Front spawning more Storms here.


I wonder exactly what is going to happen when those 2 gust fronts meet in southern Washington parish...might get a little blow up there. Showing some 65 dBz north of Abita right now.
(I can hear it, but not much rain here, ATM)
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Quoting Weather456:
Levi,

the TPC is expecting a non-frontal low to form along a trough east of the Bahamas.



That is an interesting development.

According to the GFS, cyclogenesis of that low appears to begin in 36-48 hours due to a tiny upper shortwave, which comes out of the Gulf of Mexico and moves eastward just north of the Bahamas. The actual trough-split of the longwave trough doesn't start happening until about 96 hours.



^18z GFS 48-hour 500mb^
Member Since: November 24, 2005 Posts: 635 Comments: 26647
Imagine Chinese BOP's..?

Member Since: July 3, 2005 Posts: 423 Comments: 128240
Hello guys its been awhile since the last time i posted on this blog how is everyone doing? anyways i see that next week we could be looking at some tropical mischief down in the caribean it wont be strong but hopefully it wont go to haiti thats the last thing they need. so just want to say hey.
Member Since: April 8, 2010 Posts: 15 Comments: 2572
Quoting TropicTraveler:
Bad news for Florida and the pristine waters of the keys. There is already so much oil out there I fear this is only the beginning. I can't help but wonder, is the offshore drilling within American waters or international waters? How is it that a foreign country is drilling here, do we give permits for this?


CHINA STARTS OIL DRILLING OFF FLORIDA

The Chinese are drilling under license from Cuba, within sight of Key West. The article is from 2006.
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Gheeze! WTH ?

Scientists, feds at odds over oil spill tracking model
Posted: May 18, 2010 - 4:37pm
Member Since: June 12, 2005 Posts: 6 Comments: 8186
Quoting Weather456:


Unfortunately today is the last real shower event for you guys. The CATL wave propagates west but much of the generated convection along the ITCZ remains in the WATL. The next real shower event is Saturday when the wave reaches and it might be brief and not as convective as you see now.




Sounds Good!
Much appreciated.
BBL>>>>>>>>
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Levi,

the TPC is expecting a non-frontal low to form along a trough east of the Bahamas.

Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting pottery:
Hi 456.
What's your take on the Central Atl now? That large area of heavy weather in the ITCZ. Something to watch?


Unfortunately today is the last real shower event for you guys. The CATL wave propagates west but much of the generated convection along the ITCZ remains in the CATL. The next real shower event is Saturday when the wave reaches and it might be brief and not as convective as you see now.



Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting StormChaser81:
The MODIS polygon I'm producing will be shown to all of congress tomorrow sometime.


slip in a wunderground logo and freak um all out
Member Since: July 3, 2005 Posts: 423 Comments: 128240
Quoting pottery:
Hi 456.
What's your take on the Central Atl now? That large area of heavy weather in the ITCZ. Something to watch?

I read StormW's blog on this earlier today..any changes?
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Quoting Patrap:
Big Ol Gust Front spawning more Storms here.


Boom, boom, boom, (oil) boom.
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The MODIS polygon I'm producing will be shown to all of congress tomorrow sometime.
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Quoting CybrTeddy:
Imagine how insane it would be to have 3 storms before June 1st..
that would make may more active than September of last year
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Quoting Weather456:
Vertical shear over the Caribbean will decrease but a very slow rate. Substantial drops in shear don't begin until about 1 week which presents a problem for the SW Caribbean system. Interestingly enough, if the ridge over SA and subtropical jet are aligned in such a way, it could provide ventilation for the area and the jet would work in the disturbances favor.



If the disturbance is small enough. To me significant development would be possible if the upper ridge can expand at least up to Jamaica, which means getting the 30-knot wind shear isotach up to Jamaica's latitude.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
Hi 456.
What's your take on the Central Atl now? That large area of heavy weather in the ITCZ. Something to watch?
Member Since: October 24, 2005 Posts: 0 Comments: 24307
Big Ol Gust Front spawning more Storms here.

Member Since: July 3, 2005 Posts: 423 Comments: 128240
Vertical shear over the Caribbean will decrease but a very slow rate. Substantial drops in shear don't begin until about 1 week which presents a problem for the SW Caribbean system. Interestingly enough, if the ridge over SA and subtropical jet are aligned in such a way, it could provide ventilation for the area and the jet would work in the disturbances favor.

Member Since: July 24, 2005 Posts: 407 Comments: 19076
Vancouver! Vancouver!!!, this is it!!!!!!!
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Current Convective Watches
Updated: Tue May 18 22:00:14 UTC 2010
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Laila:

Member Since: November 24, 2005 Posts: 635 Comments: 26647
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Quoting VAbeachhurricanes:
12 days till the real season, and hopefully 20 days till the 2005 comparisons end.


The comparisons to 2005 will never end at the current rate of conditions.
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Quoting Floodman:


Wow, you're exactly right...
freaky how time works. Especially when ya study astronomy.wow.
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Chennai, India doppler radar velocity:

Member Since: November 24, 2005 Posts: 635 Comments: 26647
here
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Link


Member Since: September 26, 2009 Posts: 2 Comments: 15670
We could use some rain here in Bermuda. Personally, I've only had 0.72" of rain in April and May so far. (around 1.25" at the airport). I dislike the sudden dry spell after a winter with average to slightly above average precip.
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Okay kids, I;'m out...
Member Since: August 2, 2006 Posts: 10 Comments: 9922
oops sorry I got the caps lock on
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Quoting Levi32:


Cold-core:



I have not been seeing any threat for subtropical development of this. It's taking off right up the east coast. Completely baroclinic.


Yeah. I suspected the other day that we might see Alex out of this, and even StormW was mentioning at least the possibility of such (though he didn't feel that it was very high, either) the other day.

Looking at it now though, it is indeed solidly baroclinic, completely attached to the trough. I doubt we'll see any development from this area now, but we definitely had a chance.
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Quoting Hurricanes101:


How about the 25 year anniversary of Hurricane Gloria this season as well

and in 2012 it will be 20 years since Hurricane Andrew


That is so hard to comprehend how time goes so fast
I was flying out of Newark N.J. airport just before Gloria hit. I lived in S.W. Florida when Andrew hit. That seems like it happened last night.
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Quoting hydrus:
Hey Flood. 30 years ago today we were watching Mount ST Helens erupt and Dan Rather was giving us the frightening news.


Wow, you're exactly right...
Member Since: August 2, 2006 Posts: 10 Comments: 9922
HEY XCOOL WHERE DID YOU GET THAT CAN I GET THE LINK THANK YOU
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HEY GUYS CAN'T WAIT TO SEE THESE SUB/TROPICAL SYSTEMS TO COME TRUE ANYWAY HERE IS THE NEW SURFACE MAP 18Z 18/5/10

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Another 3/4" of rain for me today so far. Looks like more showers coming too. Real nice.
The Emergency Management people here have advised that continuing heavy rains on the mountains could result in mudslides, flooding and life-threatening conditions. More rain has fallen in the mountains than here for sure, over the past few days.
6" in some areas confirmed, likely more in other areas.
Member Since: October 24, 2005 Posts: 0 Comments: 24307
yea the 1st front is cold core, no chance of development there

it is everything that happens in the next 4-5 days that will help spark these 2 systems

Like I said earlier, this is an intriguing start to the 2010 season, even if we dont get a storm. Will be interesting to see how this all plays out
Member Since: March 10, 2010 Posts: 1 Comments: 7683
Quoting hydrus:
Goin by faster and faster too. Would somebody hit the brakes damit....:}


How about the 25 year anniversary of Hurricane Gloria this season as well

and in 2012 it will be 20 years since Hurricane Andrew


That is so hard to comprehend how time goes so fast
Member Since: March 10, 2010 Posts: 1 Comments: 7683
Quoting KoritheMan:


No? The models have been latching onto possible subtropical development with this area for several days now, and have not changed since.

I realize that the primary area of concern is the possible Bahamian low in about a week or so, but there is also a chance we could get something out of the Hatteras low, as well.


Cold-core:



I have not been seeing any threat for subtropical development of this. It's taking off right up the east coast. Completely baroclinic.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
Quoting pottery:

30 years ago already???
Man. I'm getting younger...er, I mean, well, geeze! 30 years?
Goin by faster and faster too. Would somebody hit the brakes damit....:}
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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.