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: 984 - 934

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

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:
Quoting Bordonaro:
what a day from the Northern Plains all the way to SW TX. Plus TN got peppered with large hail.

Thankfully, no reports of serious injury or deaths so far, which is a good thing!



Thankfully the tornados happened in a relatively isolated area.
Member Since: Posts: Comments:
Quoting Hurricanes101:


but the models also see it emerging into the NW Caribbean in a few days


Long-term, yes. I was speaking of short-term.
Member Since: Posts: Comments:
Quoting MrstormX:


456 you hail from St. Lucia correct?


Nah, Saint Kitts
Member Since: July 24, 2005 Posts: 407 Comments: 19076
what a day from the Northern Plains all the way to SW TX. Plus TN got peppered with large hail.

Thankfully, no reports of serious injury or deaths so far, which is a good thing!

Member Since: Posts: Comments:
Quoting Weather456:


I wasn't aware T&T was holding elections. We had ours in January.


456 you hail from St. Lucia correct?
Member Since: Posts: Comments:
Kman did u see that link i posted earlier if not here it is again....Link
Member Since: Posts: Comments:
Quoting pottery:
Election results are starting to come in here.
Looks like we may have a new Government tomorrow.


I wasn't aware T&T was holding elections. We had ours in January.
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Quoting Hurricanes101:


but the models also see it emerging into the NW Caribbean in a few days


The GFS places a 1008 mb low in the neck of the Gulf of Honduras on the 29th. This low is shown as coming across Central America from the Epac.It then travels ENE to NE across the Caymans, across Cuba and out to sea. All subject to verification !

Member Since: Posts: Comments:
Quoting sarahjola:
yeah i remember that. so the high this season is going to push storms into the gulf? that worries me. after katrina, i don't have the money or resources to run anymore. i never ran before katrina and i will not run again. i don't know what was worse, not having a home or not being able to get back to my home town. both truly suck. my home in mandeville seems to dodge bad weather so i guess i'll be taking my chances this year.


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....

Member Since: Posts: Comments:
Quoting weatherblog:


Haha nope. I edited it. I meant to say "I'm 17 and have been here for nearly 4 years".

LOL
Member Since: October 24, 2005 Posts: 0 Comments: 24390
Quoting pottery:

You have been 17 for nearly 4 years?


lol that would be quite the feat
Member Since: Posts: Comments:
hey pottery how u doing
Member Since: Posts: Comments:
wunderkidcayman mail
Member Since: Posts: Comments:
Quoting pottery:

You have been 17 for nearly 4 years?


Haha nope. I edited it. I meant to say "I'm 17 and have been here for nearly 4 years".
Member Since: Posts: Comments:
Quoting weatherblog:
I'm 17 and have been for nearly 4 years. I've definitely learned a lot. If I wasn't as lazy, I could probably make really good blogs, but I don't know if I want to do this for my profession.

You have been 17 for nearly 4 years?
Member Since: October 24, 2005 Posts: 0 Comments: 24390
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?
Member Since: Posts: Comments:
Quoting stormhank:
kman..yea a quiet period from 1998 til ivan did u get many affects from irene or michelle though??


On the West coast Michelle threw up a lot of ocean water because there are no reefs there other than on the the extreme NW corner of the Island. Late season hurricanes that come up from our SW are therefore potentially very dangerous as our hotel and high end condo strip is located on the 7 mile beach on the West coast.This area is exposed to heavy onshore flow as it is a half moon shaped coast with no reef to break the waves.
Member Since: Posts: Comments:
Quoting sarahjola:

glad to hear all is well

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...
Member Since: August 16, 2007 Posts: 6 Comments: 12463
I'm 17 and have been here for nearly 4 years. I've definitely learned a lot. If I wasn't as lazy, I could probably make really good blogs, but I don't know if I want to do this for my profession.
Member Since: Posts: Comments:
Quoting KoritheMan:


Models foresee this area moving NW, agreeing well with the assessments of Avila and Blake.


but the models also see it emerging into the NW Caribbean in a few days
Member Since: Posts: Comments:
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 :(
Member Since: Posts: Comments:
Scince and technology has come far since the sattelite era of the 1960's but if you go back and read past discussions on storms u will see that pin pointing landfalls and intensities is still not perfected..computer models air recon and satellite still isnt a perfect science as storms can sometimes fool the best of us aka mother nature has no bondaries
Member Since: Posts: Comments:
Quoting wunderkidcayman:
guys I say that that yellow code in the E Pac will move over to the SW Caribbean very soon


Models foresee this area moving NW, agreeing well with the assessments of Avila and Blake.
Member Since: Posts: Comments:
If it were day I would probably chase these cells, phone in some storm reports and enjoy some thunderstorms.

Member Since: Posts: Comments:
hey stormhank yea michelle gave us hell on the northwest and north coast I live there on the coast and the waves was the main problem it almost washed my mother out to sea the waves where huge
Member Since: Posts: Comments:
Yes tropical science is an amazing thing...I wont soon forget my phone discussions with Gilbert Clark,,not sure if any of you know him. but he chatted to me alot about hurricanes he worked with John Hope who unfortunatley I never talked to he was a great hurricane specialist
Member Since: Posts: Comments:
Quoting atmoaggie:

I was in a basement in Slidell...never saw them.
But there are just a few small branches scattered about. I heard there were some power outages north of my house...

glad to hear all is well
Member Since: Posts: Comments:
Quoting kmanislander:


Swopping ruling parties is a hallmark of Westminster style politics. Somehow,they always manage to disappoint no matter how many times you clean house.

True.
Unfortunately, the Culture of Corruption (at ALL levels) here, is going to be difficult (read impossible?) to change.
This coilition may very well work, if only because there is so much for this new group to do. At all levels.
I hope it works.......
Member Since: October 24, 2005 Posts: 0 Comments: 24390
Quoting sarahjola:

yeah i know, but it would be nice if that was the case. how did you do with the thunderstorm today? was the winds strong?

I was in a basement in Slidell...never saw them.
But there are just a few small branches scattered about. I heard there were some power outages north of my house...
Member Since: August 16, 2007 Posts: 6 Comments: 12463
guys I say that that yellow code in the E Pac will move over to the SW Caribbean very soon
Member Since: Posts: Comments:
kman..yea a quiet period from 1998 til ivan did u get many affects from irene or michelle though??
Member Since: Posts: Comments:
Quoting DEKRE:


This is a strong statement. Obviously, I don't know the geographic situation, but just as an example, within my city, temperature differences can be quite drastic, especially in winter when differences of 10 °C are not uncommon, the colder the bigger the difference. If we have -25 at the airport and a low ice-cover on the St. Lawrence river, -15 is normal close to the river.
In summer the gradient is in reverse.

This is a fairly homogeneous area once you get more than a few miles inland from Lakes Pontchartrain and Maurepas. He being in Springfield with a SE wind should actually be slightly cooler than temps recorded in Hammond (this is Louisiana were talking here).
And the effect of open water in the winter is a much larger temperature difference than can be realized in the summer with a large lake or 2 that are no more than 15 degrees different than the high atmospheric temps.

No cause for 9 degrees warmer than official obs other than calibration or siting.

A few degrees cooler in a rural area than some urban or suburban ob, yeah, makes perfect sense. Not warmer.
Member Since: August 16, 2007 Posts: 6 Comments: 12463
Quoting pottery:
It looks like a "swing" vote here.
Not so much FOR the opposition "alliance", but AGAINST the existing Gov.
Corruption, bad Governance, etc etc has brought the Gov. down.
This election is 2.5 years earlier than due.


Swopping ruling parties is a hallmark of Westminster style politics. Somehow,they always manage to disappoint no matter how many times you clean house.
Member Since: Posts: Comments:
Quoting atmoaggie:

Do NOT count on the seabreeze pattern you see with T-storms to mean anything useful to you with a landfalling TC!

yeah i know, but it would be nice if that was the case. how did you do with the thunderstorm today? was the winds strong?
Member Since: Posts: Comments:
Quoting Hurricanes101:


which if that is the case, this thing may have finally shed its issues with multiple centers, problem is its still dealing with dry air and is well away from the convection

will be interesting to see what happens with it over the next 24
Definitely.
Member Since: Posts: Comments:
Quoting Herbertsbox:


Poor guy, that is funny...and cute. Damn funny
Definitely is funny looking back at it, but when I was 6 it made sense. LOL.
Member Since: Posts: Comments:
It looks like a "swing" vote here.
Not so much FOR the opposition "alliance", but AGAINST the existing Gov.
Corruption, bad Governance, etc etc has brought the Gov. down.
This election is 2.5 years earlier than due.
Member Since: October 24, 2005 Posts: 0 Comments: 24390
Quoting MiamiHurricanes09:
Looks like that little cloud feature indicated by the yellow arrow is the only surface circulation, as per WINDSAT of course.



Come on, I gave up and now all of the sudden crap starts happening again.

Edit: just joking btw...
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Looks like that little cloud feature indicated by the yellow arrow is the only surface circulation, as per WINDSAT of course.



which if that is the case, this thing may have finally shed its issues with multiple centers, problem is its still dealing with dry air and is well away from the convection

will be interesting to see what happens with it over the next 24
Member Since: Posts: Comments:
I suspect that the NHC code yellowed that in preparation of the Caribbean system.
Member Since: Posts: Comments:
Quoting Hurricanes101:


most defined the low has looked, but its way south of the convection
Looks like that little cloud feature indicated by the yellow arrow is the only surface circulation, as per WINDSAT of course.

Member Since: Posts: Comments:
I shouldve been a forecaster at NHC after all between 1986 n 1992 I called and bugged them enough,,,,they sent me seasonal summaries from 1960 thru 1992 very interesting reading...I talked to harold gerrish a few times the tropical wave in 1992 that became andrew ,, i called and told him it looked impressive he ask me should he update it to a depression lol... I really love tropical meterology
Member Since: Posts: Comments:
Quoting stormhank:
yeah Kman I know u have dealt with many,,Ivan, emily, dean,,I know camille formed near the caymans in 1969,,and of course gilbert...gotta love the islands but sometimes u deal with those uninvited guests


When you're a pin head on the map you make for a hard target. I didn't experience Camille ( was away in boarding school then ) but did get a taste of Gilbert and won't mention Ivan. Dean passed well South of us as did Felix.

In the period from Gilbert ( 1988 ) we had very little activity until Ivan and since 2004 some very close calls indeed. The Eastern Caribbean used to get hit very hard nearly every year and then it switched to the Central and Western Caribbean.
Obviously some kind of cycle at work.
Member Since: Posts: Comments:
Quoting KEEPEROFTHEGATE:
i know i forgot about that
lol


Can you hear the sound of Crying to the east of you??
Member Since: Posts: Comments:
Quoting sarahjola:

fifi? sounds like an ankle dog. that name does turn my stomach
I always wondered who picked that one for the hurricane list. Weird name for one of Mother Natures most powerful entities....jmo...
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
LMAO, Well I was 6.


Poor guy, that is funny...and cute. Damn funny
Member Since: Posts: Comments:
Quoting sarahjola:
yeah i remember that. so the high this season is going to push storms into the gulf? that worries me. after katrina, i don't have the money or resources to run anymore. i never ran before katrina and i will not run again. i don't know what was worse, not having a home or not being able to get back to my home town. both truly suck. my home in mandeville seems to dodge bad weather so i guess i'll be taking my chances this year.

Do NOT count on the seabreeze pattern you see with T-storms to mean anything useful to you with a landfalling TC!
Member Since: August 16, 2007 Posts: 6 Comments: 12463
Quoting kmanislander:


The 5 party coalition ?

Yes.
Member Since: October 24, 2005 Posts: 0 Comments: 24390
Quoting MiamiHurricanes09:
Newest WINDSAT on 90L:



most defined the low has looked, but its way south of the convection and moving SSE
Member Since: Posts: Comments:
Quoting Herbertsbox:


I don't know whether to laugh or cry...
LMAO, Well I was 6.
Member Since: Posts: Comments:

Viewing: 984 - 934

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

Mostly Cloudy
72 °F
Mostly Cloudy