90L heads for North Carolina, drenches Bermuda; oil spill changing little

By: Dr. Jeff Masters , 2:54 PM GMT on May 24, 2010

Share this Blog
3
+

An extratropical low pressure system (90L) between the Bahamas and Bermuda is moving north-northwest towards North Carolina and is close to tropical storm strength. Last night's ASCAT pass saw a large area of 35 mph winds to the north and east of the center, and buoy 41048 to northeast of 90L's center was seeing sustained ENE winds of 36 mph, gusting to 43 mph this morning. Bermuda is seeing some heavy weather from this storm, with winds blowing at 35 mph on the west end of the island, and the Bermuda radar showing an area of moderate to heavy rain moving over the island. Seas are running 5 - 10 feet in the outer waters of Bermuda today, and are expected to increase to 10 - 14 feet tonight before diminishing on Tuesday.


Figure 1. Visible satellite image of 90L this morning.

Strong upper-levels winds out of the west are creating about 25 knots of wind shear over 90L, but the shear has been gradually decreasing over the past day. Visible satellite loops show that 90L does not have a well-defined surface circulation. The main thunderstorm activity is in a large curved band to the north and northeast of the center. This band is several hundred miles removed from the center, which is characteristic of subtropical storms. I expect that 90L will continue to grow more subtropical in nature today through Wednesday as the shear continues to fall. Sea surface temperatures are near 25°C today and will fall to 23 - 24°C on Tuesday. This is warm enough to support a subtropical storm, but probably not a tropical storm. On Wednesday, 90L will be nearing the warm waters of the Gulf Stream, and SSTs will warm again, to the 24 - 25°C range. This is still pretty cool for a tropical storm, and I expect 90L will never become fully tropical. To understand the difference between a tropical and subtropical storm and why we care, see my subtropical storm tutorial.

The SHIPS model predicts that shear will fall to the medium 10 - 20 knot range by Tuesday. A large amount of dry air to 90L's southwest associated with the upper-level trough of low pressure on top of the storm, as seen on water vapor satellite loops , will hamper transition of 90L to a subtropical or tropical storm. The system will move slowly towards the Southeast U.S. coast over the next two days, making its closest approach to the coast on Wednesday, when most of the models indicate the center will be 200 - 400 miles southeast of Cape Hatteras, North Carolina. All of the major models currently predict that 90L will not make landfall, but will move slowly eastward out to sea on Thursday, when a trough of low pressure moving across the Eastern U.S. picks up the storm. There presently isn't much to be concerned with about this storm, as it appears that it will remain offshore and will become, at worst, a 40 - 50 mph subtropical storm. The National Hurricane Center (NHC) is giving 90L a medium (30% chance) of developing into a depression or tropical/subtropical storm. Wunderbloggers Weather456 and StormW have more on 90L.

Western Caribbean disturbance
A small region of disturbed weather has developed in the Western Caribbean, off the east coast of Nicaragua. Moisture is expected to increase across in this area in the coming days, and by Saturday, the GFS and NOGAPS models predict that shear will drop low enough to permit the possible development of a strong tropical disturbance or tropical depression. This storm would then move northeastward over eastern Cuba early next week. The other models keep the shear high in the Caribbean all week, and do not show anything developing. Thus, the Western Caribbean bears watching later this week, but the conditions appear marginal for development.

Moderate risk of severe weather today in northern Plains
The Storm Prediction Center has placed western Nebraska and portions of South and North Dakota under their "Moderate" risk for severe weather today. They warn that "a couple of strong and possibly long-track tornadoes appear possible given the forecast scenario." Keep an eye on the activity today with our Severe Weather Page.

Major oil threat continues for the coast of Louisiana
Light winds are expected to prevail across the northern Gulf of Mexico all week, resulting in continued oiling threats to the Louisiana shoreline from the mouth of the Mississippi River westward 150 miles, according to the latest trajectory forecasts from NOAA. There is no longer a flow of oil moving southwards towards the Loop Current, and the oil that did move southwards last week was mostly entrained into a counter-clockwise rotating eddy attached to the northern boundary of the Loop Current. Synthetic Aperture Radar (SAR) imagery over the weekend showed that most of this oil has dispersed, and very little of this oil is now visible from space (Figure 2.) Imagery from NASA's MODIS instrument and from NOAA aircraft did not show any oil in the Loop Current headed towards the Florida Keys over the weekend, so that is good news. NOAA comments that there may be some "scattered tar balls" in the Loop Current headed towards the Florida Keys. I expect these scattered tar balls have completed the full loop of the Loop Current and are now headed east towards the Keys, and will pass the Dry Tortugas and Key West sometime Wednesday - Saturday. My guess is that the oil and its accompanying plume of toxic dispersants will be too thin and scattered to cause significant problems in the Keys.


Figure 2. Synthetic Aperture Radar (SAR) image of the oil spill taken at 11:41am EDT Saturday May 22, 2010, by the European Envisat-1 satellite. Only scattered patches of oil are evident in the counter-clockwise rotating eddy on the northern boundary of the Loop Current. A small amount of oil appears to be in the Loop Current, and is moving southward. Image credit: Center for Southeastern Tropical Advanced Remote Sensing, University of Miami Rosenstiel School of Marine and Atmospheric Science. SAR images have a resolution of 8 - 50 meters, and can be taken through clouds and precipitation.

Future threats to the Keys
Mostly offshore winds are expected this week over the northern Gulf of Mexico, thanks to the approach of the 90L storm along the Southeast U.S. coast. It is uncertain if these winds will be strong enough to push oil southward into the Loop Current, though at least one ocean trajectory model does show this occurring. As I discussed in my post Wednesday, the Loop Current is very unstable right now, and is ready to cut off into a giant clockwise-rotating eddy, an event that occurs every 6 - 11 months. At least one ocean model (the Global HYCOM model from the HYCOM consortium) is predicting that such an eddy will form this week. In the event a Loop Current Eddy does break off, it would create a rotating ring of water 250 miles in diameter to the south of the oil spill. Oil moving southwards would tend to enter the giant eddy and circulate around it, not threatening any land areas. Roffer's Ocean Fishing Forecast Service has a nice discussion on the possibility of the Loop Current cutting off into a Loop Current Eddy. Keep in mind, though, that during the first month that a Loop Current Eddy forms, it exchanges a considerable amount of water with the Loop Current. Thus we can expect that a portion of any oil moving southwards into a Loop Current Eddy will find its way into the Loop Current and move past the Florida Keys.

Oil spill resources
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

I'll be back with a new post Tuesday morning.

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1034 - 984

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25Blog Index

1034. xcool
NHC pulling the plugs no lies
Member Since: September 26, 2009 Posts: 2 Comments: 15684
1033. Ossqss
Quoting KEEPEROFTHEGATE:
nothing they don't deal with on a regular basis


Not sure about that yet. Big movement of water out there, less convection, still pretty potent and will be for some time. The bouys are showing some stuff :)

Station 41048 - W Bermuda
Member Since: June 12, 2005 Posts: 6 Comments: 8186
Ok, there is something thats not making sense to me.. What may become 91L is in the epac. Its moving NW. How will that direction put it in the SW Caribbean?
Member Since: Posts: Comments:
1031. SLU
Quoting pottery:

Weather is fantastic, clear sky and the moon is dominant.
Glad to hear you are coming here, let me know when and where.
The Opposition Alliance has won the election, about 30 seats to 11.
New Prime Minister is Mrs. Kamla Persad-Bissessar. A Hindu lady, with wide support.
I hope she can deal with this Crazy place LOL



Yeh that's good. Congrats to her. Pretty major win too. Let's hope they can deal with the issues .... and in Jamaica too where things seem to be getting worse. Seems they're gonna shift the cricket from JA .... Send the games to St. Lucia!!
Member Since: Posts: Comments:
1030. KEEPEROFTHEGATE (Mod)
Quoting reedzone:
90L is not gone, still needs to get near the Gulf Stream, it has a low chance on bringing a surprise but we've had many surprises in the past. Just because the NHC gives a low chance doesn't mean it's totally gone. 90L is blowing some convection for once near the center.
ok you keep watchin let the rest of us know if something starts happening
Member Since: Posts: Comments:
90L is not gone, still needs to get near the Gulf Stream, it has a low chance on bringing a surprise but we've had many surprises in the past. Just because the NHC gives a low chance doesn't mean it's totally gone. 90L is blowing some convection for once near the center.
Member Since: Posts: Comments:
1028. pottery
Quoting SLU:
Hey pottery .. how's the weather in TnT tonight? .. will be heading your way in a few months to continue my studies.

How's the election shaping up 2night?

Weather is fantastic, clear sky and the moon is dominant.
Glad to hear you are coming here, let me know when and where.
The Opposition Alliance has won the election, about 30 seats to 11.
New Prime Minister is Mrs. Kamla Persad-Bissessar. A Hindu lady, with wide support.
I hope she can deal with this Crazy place LOL
Member Since: October 24, 2005 Posts: 0 Comments: 24460
1027. KEEPEROFTHEGATE (Mod)
Quoting Ossqss:


Don't forget it could be an issue for the shipping lanes in its future..
nothing they don't deal with on a regular basis
Member Since: Posts: Comments:
1026. SLU
Hey pottery .. how's the weather in TnT tonight? .. will be heading your way in a few months to continue my studies.

How's the election shaping up 2night?
Member Since: Posts: Comments:
1025. Ossqss
Quoting KEEPEROFTHEGATE:
90L going going ......


Don't forget it could be an issue for the shipping lanes in its future..

Delayed sorry :)

Member Since: June 12, 2005 Posts: 6 Comments: 8186
1024. SLU
Quoting KEEPEROFTHEGATE:
90L going going ......


.... gone
Member Since: Posts: Comments:
1023. pottery
Quoting KEEPEROFTHEGATE:
90L going going ......

gone.........
Member Since: October 24, 2005 Posts: 0 Comments: 24460
1022. KEEPEROFTHEGATE (Mod)
90L going going ......
Member Since: Posts: Comments:
Quoting atmoaggie:

So you know the place (my office). Right there within sight of your old school...corner of Robert and Guase.


Quite. My father was in SAC, and worked for Dyn Macdermot after he retired. So I was privy to what that building actually was. (I always wondered, as a kid, why there were dragon's teeth) I was wondering when you said 16 feet below ground, because that's the only place I know of that even HAS a basement.
Member Since: August 27, 2005 Posts: 0 Comments: 191
1020. Grothar
Quoting GeoffreyWPB:
I think Grothar is older than all of us. I think he was the Marconi operator on the Carpathia.


haha, You know-it-all. I was on the Californian sound asleep. Just stick to the weather. LOL
Member Since: Posts: Comments:
Quoting KoritheMan:


Well, I obviously can't speak for others, but I have other reasons aside from pressure rises to think that 90L is done.


The overall satellite presentation has degraded markedly since this morning.
Member Since: Posts: Comments:
Quoting gator23:
Pressure rises a little bit and this blog dies. LOL


Well, I obviously can't speak for others, but I have other reasons aside from pressure rises to think that 90L is done.
Member Since: Posts: Comments:
1017. gator23
Pressure rises a little bit and this blog dies. LOL
Member Since: Posts: Comments:
Now I'm really out, good night!
Member Since: Posts: Comments:
Quoting errantlythought:


I went to grade school at Saint Margret Mary. It was always comforting to know that I wouldn't have a clue if a nuclear war DID start. :P

So you know the place (my office). Right there within sight of your old school...corner of Robert and Guase.
Member Since: August 16, 2007 Posts: 6 Comments: 12463
Quoting ackee:
anyone suprise how high shear levels continue to be even thow we are expecting active seasons


Im not, its only May and I expect the shear to drop pretty quickly over the next few weeks

Member Since: Posts: Comments:
**OFF-TOPIC**
I know TampaSpin does not like this score, but I certainly do. Go Sox!
Member Since: Posts: Comments:
Quoting MrstormX:


Thankfully the tornados happened in a relatively isolated area.

Yes, most of the tornadoes occurred in rural ND, SD, NE, KS, and TX.

I was fortunate enough to see 2 different tornadoes, live as they happened, via 2 different storm chasers on severestudios.com. They were both large wedge tornadoes, probably of the EF-2 or EF-3 variety. Both occurred in SD, in open rural countryside.
Member Since: Posts: Comments:
1011. ackee
anyone suprise how high shear levels continue to be even thow we are expecting active seasons
Member Since: Posts: Comments:
Quoting atmoaggie:

My office is an odd place. If you told me a tornado was coming, I'd park somewhere else, but I wouldn't be worried about being in the building.
Former A-bomb-resistant cold war era DoD building...


I went to grade school at Saint Margret Mary. It was always comforting to know that I wouldn't have a clue if a nuclear war DID start. :P
Member Since: August 27, 2005 Posts: 0 Comments: 191
Quoting Weather456:
Consider all possibilities....it may be an EPAC event also.


GFS thinks so. Pretty good EPAC TS, then crossing over and redeveloping, moving ENE over cuba then East through the whole atlantic and if it somehow survives, stalling in the east atlantic
Link
Member Since: July 29, 2006 Posts: 28 Comments: 1799
Quoting Orcasystems:
BP continues using oil dispersant EPA told it to replace


WASHINGTON — BP chief executive Tony Hayward Monday defended his company's use of a chemical agent to disperse the oil leaking from a well deep under the Gulf of Mexico, despite an Environmental Protection Agency order for BP to stop using it.

The company has applied more than 600,000 gallons of the chemical, called Corexit, since the oil spill began more than a month ago, and Hayward said its use would continue. The EPA last week ordered the company to switch to a less toxic dispersant by Sunday.

"We have used dispersants from the beginning that are on the EPA approved list,” he said. "Everything we do with dispersants is with the explicit approval with the EPA."...............


I'm confused :(


From another article:
In his letter, Suttles said the only other dispersant available in sufficient quantities was Sea Brat No. 4, which contains "a small amount" of a chemical that could degrade to a nonylphonol, which has been identified by governmental agencies as "potential endocrine disruptors" that "may persist in the environment for a period of years."

From the wiki on nonylphonol:
Nonylphenol is considered to be an endocrine disruptor due to weak ability to mimic estrogen and in turn disrupt the natural balance of hormones in a given organism. The effect is weak because nonylphenols are not very close structural mimics of estradiol, but the levels of nonylphenol are sufficiently high to compensate.
Structure of the hormone estradiol and one of the nonylphenols.

Occurrence in the environment

Nonylphenol has been detected widely in waste water streams across the globe, which is a concern since it is toxic to many aquatic organisms. For example, nonylphenol has been detected both in the Great Lakes and in the region of New York City. In 1984, the formation of 4-nonylphenols from nonylphenol ethoxylates in wastewater treatment plants was first discovered. Nonylphenol is persistent in the environment, therefore lingers with the potential to negatively affect organisms it comes in contact with. Nonylphenol also bioaccumulates, which is dangerous to animals and humans who eat meat.

Environmental protection policies

Nonylphenol and nonyphenol ethoxylates have been banned in the European Union as a hazard to human and environmental safety.

For freshwater ecosystems, the Environmental Protection Agency has set two types of standards: the first which is considered acute criteria is one-hour average concentration of nonylphenol does not exceed 28 μg/L more than once every three years on the average.

For saltwater ecosystems, the standard is considered to be chronic criteria and is set to four-day average concentration of nonylphenol that does not exceed 6.6 μg/l more than once every three years on the average.

atmo: Years? Bioaccumulation? Danger to animals and humans? So, if BP's point about the EPA's choice is accurate, it is hard to believe that the oil itself is worse than this dispersant. (assuming for the moment we are getting accurate information)
Member Since: August 16, 2007 Posts: 6 Comments: 12463
I hope by the heart of hurricane season that oil spill will be resolved,,never the less if a major hurricane passed thru the gulf it would be awful ... fact being i dont see a oil spill weakining a storm with tides and winds and such...
Member Since: Posts: Comments:
Quoting stormhank:
Agreed Kman...I dont suppose anyone knows where storms will make landfall this year,,active or otherwise only steering patterns will determine that
Each season is different. I don't recall seeing a season with the same amount of systems making landfall in the same place, so a "pattern" really isn't useful, I guess it's one of those "time will tell" type of things.
Member Since: Posts: Comments:
Well folks I'm out for tonight. Watched the end of Lost last night so it looks like two and a half men tonight LOL.

Take care. catch you all tomorrow.
Member Since: Posts: Comments:
Quoting stormhank:
Agreed Kman...I dont suppose anyone knows where storms will make landfall this year,,active or otherwise only steering patterns will determine that


Not even the shadow knows LOL
Member Since: Posts: Comments:
Agreed Kman...I dont suppose anyone knows where storms will make landfall this year,,active or otherwise only steering patterns will determine that
Member Since: Posts: Comments:
Quoting sarahjola:

good! the last thing we need is a storm stirring up all that oil.


Yeah. Hopefully conditions stay unfavorable until at least August, at which point they will hopefully have the oil well capped.
Member Since: Posts: Comments:
1001. pottery
Quoting hydrus:
lol. I see you are receiving rain quite regularly now. A new government? I hope the one you get is a good one Pott.

Me Too!!!
Member Since: October 24, 2005 Posts: 0 Comments: 24460
Quoting stormhank:
Im thinking one June storm,,,then as the shear lessens it'll prob pop in july


My thinking is one depression and one TS between now and June 30th, much like 2005. Throw in an invest or two that don't quite make it to classification level.

Even in very active years June is not known for explosive activity.
Member Since: Posts: Comments:
Quoting KoritheMan:


As of now, chances are that this thing stays completely out of the Gulf of Mexico.

good! the last thing we need is a storm stirring up all that oil.
Member Since: Posts: Comments:
Quoting Orcasystems:
BP continues using oil dispersant EPA told it to replace


WASHINGTON — BP chief executive Tony Hayward Monday defended his company's use of a chemical agent to disperse the oil leaking from a well deep under the Gulf of Mexico, despite an Environmental Protection Agency order for BP to stop using it.

The company has applied more than 600,000 gallons of the chemical, called Corexit, since the oil spill began more than a month ago, and Hayward said its use would continue. The EPA last week ordered the company to switch to a less toxic dispersant by Sunday.

"We have used dispersants from the beginning that are on the EPA approved list,” he said. "Everything we do with dispersants is with the explicit approval with the EPA."...............


I'm confused :(


Then all is going according to plan!
Member Since: Posts: Comments:
Im thinking one June storm,,,then as the shear lessens it'll prob pop in july
Member Since: Posts: Comments:
Quoting pottery:

You have been 17 for nearly 4 years?

Well, I've been 19 for 15 years, myself...
Member Since: August 16, 2007 Posts: 6 Comments: 12463
Good night!
Member Since: Posts: Comments:
Hey weather 456..
Member Since: Posts: Comments:
Quoting Weather456:
Consider all possibilities....it may be an EPAC event also.


I find this more likely.
Member Since: Posts: Comments:
Quoting pottery:

You have been 17 for nearly 4 years?
lol. I see you are receiving rain quite regularly now. A new government? I hope the one you get is a good one Pott.
Member Since: Posts: Comments:
Quoting kmanislander:
The next few days will likely be relatively quiet and boring. Once you get a system close to the Eastern seaboard it tends to shut down the Caribbean due to shear.

Very typical.
Member Since: Posts: Comments:
Quoting Dakster:


What's worse - How about losing your life?

IF a Cat3+ is coming your way, please e-mail your next of kin information to someone not in your hometown and cc: your local police department.

I really hope that no one here would base their decision to stay or leave on your statement alone....


i don't have the money or resources to leave again. that is the reason i will stay for any storms. i lived in st. Bernard for Katrina so i don't have to be told of the dangers. i know. but if you have nowhere to go and no money to take you there you have to take your chances. my home is 17 feet higher than my old home. was once below sea level now I'm not. people in my old parish would have been fine if the levees would have held. out here I'm not worried about drowning. i do worry about the trees though. as for my next of kin, well they are in st. Bernard still and they would be coming to my house for storms.
Member Since: Posts: Comments:
The next few days will likely be relatively quiet and boring. Once you get a system close to the Eastern seaboard it tends to shut down the Caribbean due to shear.

Member Since: Posts: Comments:
Consider all possibilities....it may be an EPAC event also.
Member Since: Posts: Comments:
Quoting sarahjola:
when and if this system gets into the Caribbean where will it go? will the gulf coast have to watch this or will this most likely be a Caribbean storm and pass us by?


As of now, chances are that this thing stays completely out of the Gulf of Mexico.
Member Since: Posts: Comments:
Quoting kmanislander:


No I didn't but just took a quick look. I hope they are wrong.
Me too.
Member Since: Posts: Comments:
Quoting stormhank:
Kman did u see that link i posted earlier if not here it is again....Link


No I didn't but just took a quick look. I hope they are wrong.
Member Since: Posts: Comments:

Viewing: 1034 - 984

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25Blog Index

Top of Page

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.

Local Weather

Overcast
52 °F
Overcast