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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820. HadesGodWyvern (Mod)
India Meteorological Department
Tropical Cyclone Advisory NUMBER ONE
DEPRESSION ARB01-2010
14:30 PM IST May 19 2010
=======================================

At 9:00 AM UTC, Latest satellite imagery indicates that a depression has formed over southwest Arabian Sea off Somalia coast and lays centered near 10.5N 54.0E, or about 400 kms off Alulu, Somalia. The system is likely to intensify further and move slowly in a northwesterly direction towards the Gulf of Aden during the next 2-3 days.

Convective clods in association with the system has organized during the past 24 hours. The estimated dvorak intensity is T1.5. The 3 minute sustained winds is 25 knots. Broken intense to very intense convection is seen over west Arabian Sea between 8.0N to 11.0N and west of 56.0E.
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Quoting Stormchaser2007:
Looks like this may interfere with todays severe weather outbreak a bit.


The main activity today will be to the south and southwest of this mornings MCS (squall-line).

The atmosphere will be destabilized by the approaching L to the west, and associated dryline, wind shear is about 60KT.

Daytime heating will send the CAPE up into the 1500 J/KG, very unstable. Add cold air aloft a westerly Jet (@100KT), SE surface winds of 20KTS, dew points near 65-70F.

The recipe for supercells that will "spin like a merry-go-round, with twisters!!
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from cnn

Tar balls discovered on the Florida Keys shoreline are not connected to the oil spill in the Gulf of Mexico, the Coast Guard said Wednesday.

Tests done "conclusively show" that the tar balls found on the shoreline do not match the type of oil from the Deepwater Horizon oil spill. The source of the tar balls remains unknown at this time.

"The conclusion that these tar balls are not from the Deepwater Horizon oil spill incident in no way diminishes the need to continue to aggressively identify and clean up tar ball-contaminated areas in the Florida Keys," Capt. Pat DeQuattro, commanding officer of the Coast Guard's Key West sector said. "We will continue to operate as a Unified Command and utilize funding through the Oil Spill Liability Trust Fund until we have successfully identified any additional tar balls on the shoreline and completed cleanup efforts."

i find this hard to believe

morning everyone
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Blog Update

40-50% chance of La Nina this summer/fall; two areas to watch next week

Be back a little later.

Member Since: July 24, 2005 Posts: 407 Comments: 19076
Ah ha! For all of you on the edge of your seat waiting for me to figure out how to find my Bold, Link, Italics, and Image buttons; it appears it is the fault of the browser. I was using Google Chrome - I switched to Explorer and it shows the buttons. Eureka!
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814. HadesGodWyvern (Mod)
India Meteorological Department
Tropical Cyclone Advisory NUMBER FIFTEEN
SEVERE CYCLONIC STORM LAILA (BOB01-2010)
14:30 PM IST May 19 2010
====================================

At 9:00 AM UTC, Severe Cyclonic Storm Laila over southwest and adjoining west central Bay of Bengal moved northwest and lays centered over west central and adjoining southwest Bay of Bengal near 14.0N 81.5E, or 150 kms northeast of Chennai, 250 kms south southeast of Machilipatnam, and 500 kms south southwest of Visakhapatnam.

3 minute sustained winds near the center is 55 knots with a central pressure of 986 hPa. The state of the sea is very high around the system's center.

Satellite imagery indicates banding pattern of the system The dvorak intensity of the system is T3.5. Associated broken intense to very intense convection observed over the Bay of Bengal between 10.0 to 18.0N. The lowest cloud top temperature due to convection is -90C in association with the system.

Vertical wind shear of horizontal wind over the region is 10-15 knots. The system lies to the south of tropospheric ridge, which roughly runs along 17.0N. The system is under the influence of anticyclonic circulation located to the northeast of the system center. Shear tendency over the past 24 hours is negaive to the north of system.

Considering all the above and numerical weather prediction model guidance, the system is likely to intensify further and move in a northwesterly to northerly direction and cross Andhra Pradesh coast between Nellore and Kakinada, close to Machilipatnam by Thursday morning.

Forecast and Intensity
=========================
21 HRS: 16.0N 81.0E - 65 knots (Very Severe Cyclonic Storm)
45 HRS: 18.5N 83.5E - 45 knots (Cyclonic Storm)
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Quoting hurricane23:
The NOAA hurricane outlook was postponed by high-level NOAA management, most likely because of the oil spill hearing conflicting with the scheduled release time/day and they were going to be stuck in DC when the event was in Miami. It will be released the 27th.


Thanks for the update. So that's a week from Thursday (tomorrow). Postponed by 1 week.
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Quoting indianrivguy:
and in today's "headlines"



Sebastian River High School student Coral Pearce, 15, shaved her head last weekend and donated the 10-inch locks to help sop up the spill. She also buzzed the words “No Oil” into the remaining hair on the back of her head to let people know where she stands when it comes to ecology.


Saw that on the news last night. Don't suppose she cut a deal with Greenpeace for advertising dollars. Wonder if Dick Cheney has ""Oil Rocks!" carved on his head?
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The NOAA hurricane outlook was postponed by high-level NOAA management, most likely because of the oil spill hearing conflicting with the scheduled release time/day and they were going to be stuck in DC when the event was in Miami. It will be released the 27th.
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Hmmm. Gonna try a different computer. I wonder if being logged in on my little Acer Aspire at the same time as my phone (Nexus One - Android) is causing the difficulty? Blasted electrons! Behave yourselves!

Reminds me, did you hear about the unhappy proton at the bar? Bartender asked what was wrong and he said he lost an electron.
"Are you sure?"
"I'm positive."
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and in today's "headlines"



Sebastian River High School student Coral Pearce, 15, shaved her head last weekend and donated the 10-inch locks to help sop up the spill. She also buzzed the words “No Oil” into the remaining hair on the back of her head to let people know where she stands when it comes to ecology.
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807. IKE
Quoting mikatnight:


Hey Ike,
This is so weird. Are the bold and italics buttons still there as well? Also missing those...


Yeah...they're all there. Not a computer whiz...maybe one is on here.

Sorry.

Do you not see where it says "Selected Text:" or "User Name" or "Date"?
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Quoting IKE:


It's on mine....right above your quote.


Hey Ike,
This is so weird. Are the bold and italics buttons still there as well? Also missing those...
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TC LAILA

Thankfully, the heaviest rains and winds remain offshore for the time being



Rain amount over next 72 hrs





DOPPLER PRODUCT(MAX(Z))-CHENNAI

Member Since: July 24, 2005 Posts: 407 Comments: 19076
The Link button looks like it should be the underline button. It is between BOLD and Italics
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803. IKE
A lot of clouds in the western Caribbean.
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Good Morning.

Amazing animations of the GOM surface on ROFFS.

pressure question:
Should the oil in the mile vertical pipe that is 1/5 lighter than water, shoot up 1/5 of a mile above the ocean surface before pressure is equalized?

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799. IKE
Quoting mikatnight:


Thanks! Your answer is both a relief and frustrating. Relieved that it's not me, frustrating because there is no link button on my page anymore (I thought there must've been a new way).
Awright, which one of you knuckleheads ran off with my link button?


It's on mine....right above your quote.
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Quoting doabarrelroll:
You click the link button that is located above the comments section and just copy and paste


Thanks! Your answer is both a relief and frustrating. Relieved that it's not me, frustrating because there is no link button on my page anymore (I thought there must've been a new way).
Awright, which one of you knuckleheads ran off with my link button?
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Quoting Weather456:
NOGAPS



That looks like a monster high, does the NOGAPS keep it south or does some weakness get involved? Also noticing, not even a hint of a low near the Bahamas.
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Quoting doabarrelroll:
BREAKING NEWS KEY WEST TAR BALLS NOT FROM BP SPILL
Link


Guess Aussie was right. They musta come from Mars.
Member Since: August 13, 2005 Posts: 177 Comments: 26630
795. Skyepony (Mod)
ESPI has tanked.. -0.48 I like a strong La Nina by August.

TRMM rainfall

China is getting poured on again..
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Looks like this may interfere with todays severe weather outbreak a bit.

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Quoting hurricane23:


The 00z ECMWF is pretty aggresive on a possible Hybrid low retrograding it towards florida.


Yea I saw that
Member Since: July 24, 2005 Posts: 407 Comments: 19076
757 pottery "This is quite complex, and I am not sure what you are trying to conclude.
Is it that the oil flowing out of the pipe has to be at a pressure greater than 2670 psi? At the level of the sea bed?
"

You telling me... I'm just trying to think on it from a basic physics standpoint...and making a lot of assumptions on the way.

My conclusion is that the maximum pressure on the broken wellhead (if it were capped off) would be 2670psi...given the constraint of my assumptions about rock density and crude density.

AND given my lack of information about how much structural strength that the rock has. The amount that the porous rock self-supports itself without the crude oil pressure lessens that crude oil pressure by a similar amount.

AND given my lack of information about the amount of methane (and other gases) flowing up with the crude, which would increase the pressure as the gases expand on their way upward.
This would increase the pressures in both pipes: the ~370psi in the pipe from the seabed to the surface, and the 2670psi from the bottom of the well to the break just above the BlowoutPreventer.
Possibly by a tremendous amount.
eg They are degassing the carbon-saturated deep waters of Lake Nyos by essentially sticking a straw in it. Now sticking the pipe leading from the surface down into the deepwaters wouldn't do anything by itself; the colder and thus heavier water would just sit in the bottom of the pipe.
However by sucking on the pipe with a pump, the cold water starts moving upward. And as the cold water moves upward, the decrease in pressure causes the dissolved carbon dioxide to come out of solution and form bubbles.
Those carbon dioxide bubbles mixing with water decrease the density of the column until it's below that of the upper waters...producing upward pressure that sucks at the bottom of the pipe.
Remove the pump, and the out-gassing continues. So the upward pressure continues to draw water from the bottom of the pipe. And voila, ya got a self-pumping straw shooting water high into the air at the surface. No outside power input necessary.

AND given my lack of knowledge about how pipe materials and pipe diameters affect the drag upon material flowing within the pipe. Which would decrease the velocity at which crude oil spews out of the leaks, which in turn would decrease the amount.

I'm sure I can come up with other lacks on my part.
And that the engineers working on the capping problems would find my lacks to be understated to the point of etc ad nauseum... but that's why they get paid the big bucks.

Just trying to get folks to understand that the solutions are tougher to come up with than "stick a fork in it and say it's done"
Member Since: August 21, 2007 Posts: 0 Comments: 4860
NOGAPS

Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting reedzone:
Looking at the CIMMS shear map, I see high wind shear lifting north in the Carribean. So development down in the WC, looks mroe lkely to me then before, now that I'm seeing what the models were showing earlier with the shear lifting northward. Also to note that there is convection firing up in that area, this is probably where the invest area will develop so things are now starting to ramp up down there. As for the Subtropical potential, still up in the air in my opinion, but when the EURO goes aggressive on something in the short/medium range, I pay attention. Invest 90L to come soon this weekend.


you know I was saying earler that the shear will ease and help our soon 90l
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Quoting Drakoen:


Yes. It appears very hyrbid though with a large 850mb circulation above the surface circulation.


Haha, I remember Andrea, she was large, hybrid, and made out of popcorn storms :P
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Quoting doabarrelroll:
BREAKING NEWS KEY WEST TAR BALLS NOT FROM BP SPILL
Link


Well kiss my grits. I was sure they were. Guess that's why I'm an electrician.

Hey, howdja post that linky thingy?
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785. IKE
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Quoting Jeff9641:


Did you see what the Euro does off the east coast of Florida by day 7? Impressive if this continues each model run.


Yes. It appears very hyrbid though with a large 850mb circulation above the surface circulation.
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Looking at the CIMMS shear map, I see high wind shear lifting north in the Carribean. So development down in the WC, looks mroe lkely to me then before, now that I'm seeing what the models were showing earlier with the shear lifting northward. Also to note that there is convection firing up in that area, this is probably where the invest area will develop so things are now starting to ramp up down there. As for the Subtropical potential, still up in the air in my opinion, but when the EURO goes aggressive on something in the short/medium range, I pay attention. Invest 90L to come soon this weekend.
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Hey ya'll. Been off the blog for a while and I see they've changed a few things. Like, how do you post a link now? The buttons are gone! Reckon I'm pc challenged...
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Quoting Weather456:


Welcome aboard.


The 00z ECMWF is pretty aggresive on a possible Hybrid low retrograding it towards florida.
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Impressive.



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Quoting hurricane23:
Morning,

The GFS ensembles, the operational ECMWF and ECMWF ensembles all show this developing to some degree in the sw caribbean. I guess it's a plausible scenario given the warm ssts down there and the weak spot in the westerlies south of the zonal jet.


Yep computer models continue to indicate development down there. I put chances of something forming in the Caribbean over the next 7 days at Moderate.
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8 to 10 DAY 500MB MEAN
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772. eddye
jeff 9641 dont u mean south florida 2 because i see them near the keys coming to south florida
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Quoting hurricane23:
Morning,

The GFS ensembles, the operational ECMWF and ECMWF ensembles all show this developing to some degree in the sw caribbean.I guess it's a plausible scenario given the warm ssts down there and the weak spot in the westerlies south of the zonal jet.


Welcome aboard.
Member Since: July 24, 2005 Posts: 407 Comments: 19076

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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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