Oil enters the Loop Current and is headed to the Florida Keys
Satellite imagery today from NASA's MODIS instrument confirms that a substantial tongue of oil has moved southeast from the Deepwater Horizon oil spill and entered the Gulf of Mexico's Loop Current. 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 then along the west side of the western Bahamas. Here, the waters of the Loop Current flow northward along the U.S. coast and become the Gulf Stream. 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 10 - 20 days. Portions of the Loop Current flow at speed up to 4 mph, so the transport could be just 4 - 5 days. It now appears likely that the first Florida beaches to see oil from the spill will be in the Lower Florida Keys, not in the Panhandle.
Figure 1. Satellite image of the oil spill taken at 12:40 EDT Monday May 17, 2010. The location of the Loop Current is superimposed. Image credit: University of Wisconsin and NASA.
Why is oil getting into the Loop Current?
The winds over the oil spill location are offshore out of the northwest today, and offshore winds will continue intermittently through Wednesday, which should allow a substantial amount of oil to enter the Loop Current. The major reason oil is moving southwards is because of the instability of the currents in the Gulf of Mexico. The Loop Current is not a stable feature, and tends to surge northwards and southwards in a chaotic fashion, and in response to changes in the prevailing winds. Over the past week, chaotic behavior of the Loop Current and a clockwise-rotating eddy just to its north, just south of the oil spill location, have combined to bring a current of southward-moving surface water to the oil spill location. As strong on-shore winds from the southeast slackened this past weekend, oil has been drawn southward into the Loop Current. The latest NOAA trajectory forecasts failed to anticipate the movement of the oil into the Loop Current. The latest surface current forecasts from NOAA's HYCOM model show that oil could continue pouring into the Loop Current for most of the rest of the week. It is highly uncertain how diluted the oil might get on its voyage to northwestern Cuba and the Florida Keys this week, but the possibility for a major ecological disaster in the fragile Keys ecosystem cannot be ruled out. Southeast to east winds of 10 - 15 knots are expected to develop late this week and extend into early next week, which may be strong enough to impose a surface current that will shut off the flow of oil into the Loop Current by Friday or Saturday.
Figure 2. Forecast made at 8pm EDT Sunday May 16, 2010, of the Gulf of Mexico currents by NOAA's HYCOM model. A persistent southward flowing surface current is predicted to occur this week between the oil spill location (red dot) and the Loop Current. Image credit: NOAA.
Likely areas of impact
Based on a study of 194 floating probes released into the Northeast Gulf of Mexico during a 1-year study in the 1990s (Figure 3), the west coast of Florida from Tampa Bay southwards to the Everglades is at minimal risk of receiving oil from surface currents. There is a "forbidden zone" off the southwest Florida coast where the shape of the coast, bottom configuration, and prevailing winds all act to create upwelling and surface currents that tend to take water away from the coast. This study implies that the greatest risk of land impacts by surface oil caught in the Loop Current is along the ocean side of the Florida Keys, and along the coast of Southeast Florida from Miami to West Palm Beach. Eddies breaking away from the Gulf Stream would also likely bring oil to northwest Cuba, the western Bahamas, and the U.S. East Coast as far north as Cape Hatteras, North Carolina, though at lesser concentrations. Southwest Florida cannot rest entirely, though--the "forbidden zone" is only true for surface waters, and there is onshore flow below the surface. Since recent ship measurements have detected substantial plumes of oil beneath the surface, southwest Florida might be at risk if one of these plumes gets entrained into the Loop Current. These subsurface plumes were also detected by current probes launched into the oil spill on May 8 by one of NOAA's hurricane hunter aircraft, according to one scientist I spoke to at last week's AMS hurricane conference. There are plans for the Hurricane Hunters to go out again tomorrow and drop more probes into the spill to attempt to get a better handle on where the oil is and where the currents are taking it.
Figure 3. Paths of 194 floating probes released into the yellow-outlined area in the northeast Gulf of Mexico between February 1996 and February 1997 as part of a study by the Mineral Management Service (MMS). The probes were all launched into waters with depth between 20 and 60 meters. Image credit: Yang, H., R.H. Weisberga, P.P. Niilerb, W. Sturgesc, and W. Johnson, 1999, Lagrangian circulation and forbidden zone on the West Florida Shelf, Continental Shelf Research Volume 19, Issue 9, July 1999, Pages 1221-1245 doi:10.1016/S0278-4343(99)00021-7
When will a Loop Current eddy break off?
Every 6 - 11 months, the looped portion of the Loop Current cuts off into a clockwise-rotating ring of water that then slowly drifts west-southwest towards Texas. When one of these rings breaks off at the peak of hurricane season, it provides a source of heat energy capable of providing fuel for rapid intensification of any hurricanes that might cross over. The Loop Current is not predicted to shed an ring over the next month, as predicted by the latest 1-month forecast from the U.S. Navy. However, the last eddy broke off in July of 2009, ten month ago, and it is unusual for the Loop Current to go more than eleven months without shedding an eddy. I expect we'll see the Loop Current shed an eddy in July or August, just in time to pose the maximum threat for hurricane season. According to an interesting February 2004 article published by offshore-engineer.com, reliable forecasts of these currents and eddies are not available yet. Keep in mind that surface currents are largely driven by winds, and wind forecasts are not reliable out more than about 10 days.
References
Yang, H., R.H. Weisberga, P.P. Niilerb, W. Sturgesc, and W. Johnson, 1999, Lagrangian circulation and forbidden zone on the West Florida Shelf, Continental Shelf Research Volume 19, Issue 9, July 1999, Pages 1221-1245 doi:10.1016/S0278-4343(99)00021-7.
Oil spill resources
NOAA trajectory forecasts
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
Jeff Masters
Reader Comments
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Peter Max ;)
:)
Hot summer streets and the pavements are burning I sit around
Trying to smile but the air is so heavy and dry
Strange voices are sayin'
What did they say
Things I can't understand
It's too close for comfort this heat has got right out of hand
It's a cruel ... cruel ... cruel summer
Leaving me here on my own
It's a cruel ... it's a cruel ... cruel summer
Now you've gone
Tropical Cyclone Outlook
18:00 PM UTC May 18 2010
============================
An area of convection (93A) located at 11.0N 55.5E or 250 NM east of Cape Guardafui, Somalia. Animated infrared satellite imagery depicts persistent deep convection near a slowly developing low level circulation center. A 1402z WINDSAT image indicated formative convective banding wrapping from the south into the northeast quadrant. A 0616z ASCAT ambiguity analysis shows a defined low level circulation center with 20-25 knot winds near the center and convergent flow along the southern semi-circle. The 0900z surface observation from Socotra, Yeman indicates 040/20 knots. Upper level analysis indicates a more favorable environment with weak vertical wind shear diffluent flow over the low level circulation center. The system is expected to contiue developing, aided by the enhanced southwesterly flow and improved northwesterly flow over Yeman.
Sustained winds near the center is 20-25 knots with a minimal sea level pressure of 1005 MB. The potential for this disturbance to form into a significant tropical cyclone within the next 24 hours is UPGRADED TO FAIR.
Why does the Raleigh websites ECMWF look so different than the other website?
Day 6....
Day 7...
It's simply the difference in how each website render model data.
I am sure that we will see some interesting,
great analysis this season... I have a feeling
growing inside that we might see some nasty,
enormous storms this year... most likely
right around the GOM to southeast US...many
should pay attention this summer...it could mean many lives saved... ST5K
ok but it is very differnt it looks like at time
while the Raleigh site shows the low in the SW Caribbean, the other site barely even hints at it
MSLP:
500mb:
The Raleigh site spaces the isobars 2mb apart, while the ECMWF site has them 5mb apart. The former is much better for viewing tropical features which show up better with smaller spacing. In the tropics it's hard to get a 5mb change in pressure unless it's associated with a large or powerful feature.
I agree it's different. It's hard at times to figure out what's going on with the ECMWF model run provided on this website.
To someone not educated enough... I have to look the run over for a few minutes to see what it's saying.
This is a good jigsaw puzzle to try and figure out for next week and a good little starter for the 2010 season, some nice practice
Maybe TWC will run a Storm as well.
Pressures look higher here than on previous runs and other models, including the Caribbean where the other weak low is. I think they will be a bit lower than this, but regardless you can see the possibilities with a trough-split getting stuck under a block to sit in this area for several days. At least subtropical mischief is definitely a possibility here.
BP says it will never try to re-open damaged well
by Jeffrey Collins and Jason Dearen / Associated Press
wwltv.com
Posted on May 17, 2010 at 2:52 PM
Updated yesterday at 3:33 PM
BP said Monday it hopes to siphon as much as half of the oil leaking into the Gulf of Mexico and is getting ready to shoot mud into a blown-out well later this week to try and stop all of it.
BP PLC chief operating officer Doug Suttles said at a press conference that the company will never again try to produce oil from the well, though BP did not rule out drilling elsewhere in the reservoir.
"The right thing to do is permanently plug this well, and that's what we will do," Suttles said.
Meanwhile, scientists said they were concerned about the ooze reaching a major ocean current that could carry it through the Florida Keys and up the East Coast. Suttles said a mile-long tube is funneling a little more than 42,000 gallons of crude a day from a blown-out well into a tanker ship.
This could be the mess that the GFS is still trying to figure out. The Euro seems to have a good handle on taking the baroclinic low out but still leaving the cut-off piece behind, which makes a lot of sense. The GFS 12z is starting to figure it out by trying to leave a piece behind, unlike previous runs which took the whole thing out and phased it with the longwave trough. It still doesn't have as good a handle on it as the Euro though.
8-14 day...
I'm pretty sure most stuff this time of year would head to the east and keep going.
If the trough-split piece gets blocked by the ridge over the NE US then yes it would retrograde westward towards Florida, which is shown on the Euro. Whether it develops or not will be worked out as the situation evolves. Wind shear is part of that, and due to the complexity of the situation we can't know for sure, but if the surface circulation becomes vertically stacked with the upper low, then wind shear won't be as much of a problem for it.
Actually, that area is under a pocket of 5-10 knots of wind shear. The potential low is forecast to form off of that this weekend, or early next week.
EBS activated Marine Warnings for Lakefront Marina,ST Tammany,St Bernard,Jefferson..etc,
Boomers ,,big uns.
Im just south looking up at um grow.
Boomers,..nasty ones.
NOAA Radio going berserk with Marine warnings
The one that develops near or east of the Bahamas is the one east of Florida on the Euro. Nothing forming near Bermuda is going to end up near Florida. If a low moves near Bermuda it would be a baroclinic one taking off and phasing with the longwave trough to the north, leaving another piece behind near the Bahamas.
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