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: 784 - 734

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 nrtiwlnvragn:
This low in the Carribean can't be the one talked about as a potential storm. Also looks like TAFB is leaning toward frontal for 90L




:)
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
27 Named storms, wow, I hope that they're wrong. Ufff, I'm not liking this graph, My neck of the woods (Miami) In red.


Seems like the strike zones are little more than a lesson in climatology, to me...
Member Since: August 16, 2007 Posts: 6 Comments: 12463
Quoting sarahjola:

isn't this typical risk for hurricane season? i mean the spots in red and orange. that is typical spots for hurricanes to hit.
Not really. Steering has to do a lot with the location of the Bermuda high. Let me give an example:

In 2009 the Bermuda high was strong but it was very east, this in result caused many storms to curve out to sea.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting CybrTeddy:
If we get 27 named.. what do we Call Alpha - Zeta?


Alpha - Zeta lol
Member Since: March 10, 2010 Posts: 1 Comments: 7874
Quoting MiamiHurricanes09:
27 Named storms, wow, I hope that they're wrong. Ufff, I'm not liking this graph, My neck of the woods (Miami) In red.


isn't this typical risk for hurricane season? i mean the spots in red and orange. that is typical spots for hurricanes to hit.
Member Since: September 10, 2008 Posts: 0 Comments: 1294
If we get 27 named.. what do we Call Alpha - Zeta?
Member Since: Posts: Comments:
oh sweet am was post 777
Member Since: Posts: Comments:
i think will have are 1st name storm this weekend or next week
Member Since: Posts: Comments:
Quoting weathersp:


http://www.nws.noaa.gov/om/tpb/472bbody.html

http://www.gfdl.noaa.gov/operational-hurricane-forecasting


I read through both of those documents, and nowhere does it say to ignore atmospheric features outside of the inner nest. Yes the resolution of the model is lower in other areas, but within its limited domain it functions like any other limited domain model (NAM, RUC, WRF), it resolves equations to predict the atmosphere. Is it a guarantee of cyclogensis? No, just another tool to use to indicate areas of possible cyclogensis.
Member Since: Posts: Comments:
Quoting stormwatcherCI:
Yellow.
Guess I was wrong.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting Tazmanian:
this is mine


1929 comments and 35 entries posted by all members in the last 24 hours.

You have posted 5073 entries in your own blog.

You have posted 41629 comments in all blogs.



we may have all have 100,000 too 50,000 commets made by this year end
Where do you find those numbers?
Member Since: September 2, 2009 Posts: 130 Comments: 21194
i want a heat wave
Member Since: Posts: Comments:
Quoting CybrTeddy:


Jesus.. thats 2005 level activity.
Someone say 6,000 posts a day in this season?
Wow.. thats just astonishing.. no words to describe.


A few years ago...this site shut down because it reached its maximum number of posts. We had to post on someone's personal blog to carry on. And JFV was the last person whose post got through, he modified and told everyone where to go!

Member Since: Posts: Comments:
Hey Spud we love you and thanks to Dr. Masters for calling in to WWL 870. What Dr, Masters said is one our biggest fears here, there is great potential for a storm to hit this spill. We are scared to think of what will happen then. Thanks Pat for posting the link.


Quoting Patrap:
Dr. Jeff Masters excerpt from the Spuds McKenzie show on WWL.com Radio NOLA today.

Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
I think it's improving, let's see what the NHC says in the next special advisory.
Yellow.
Member Since: Posts: Comments:
this is mine


1929 comments and 35 entries posted by all members in the last 24 hours.

You have posted 5073 entries in your own blog.

You have posted 41629 comments in all blogs.



we may have all have 100,000 too 50,000 commets made by this year end
Member Since: Posts: Comments:
The part that got me was that they're forecasting 7-8 named storms, 3-4 hurricanes, and 1-2 major hurricanes before August.

I actually agree with this strike map.

Member Since: Posts: Comments:
Does anyone know the shear values outlook for this year? granted I know you cant look out that far but, All the ingredients comin together for an active season that Ive read, does the shear values get added into the mix?? even though El Nino is gone, they still could be areas of high shear correct? any input always appreciated and thanks!!!!
Member Since: Posts: Comments:
Quoting wadedanielsmith:
Yesterday was Like Aug here.

We hit 95F and 103f Heat Index around 4pm-5pm


My heavily shaded thermometer just hit 104.9F and 26% humidity...

Pressure is actually down some though, at 1011mb...

Springfield, LA...

Meteorologically, this makes no sense. Hammond never even hit 95 yesterday and did today for one hour. And that ob has a known warm bias.

Does your water freeze at 41? Boil at 221?

Something simply isn't right. Your ob or all of the official ones. Calibration or placement. (In the shade but next to a dark colored wall that gets sun?)

PWS stations are so very badly calibrated sometimes...(I know you said it was calibrated)
Member Since: August 16, 2007 Posts: 6 Comments: 12463


National Hurricane Preparedness Week

History teaches that a lack of hurricane awareness and preparation are common threads among all major hurricane disasters. By knowing your vulnerability and what actions you should take, you can reduce the effects of a hurricane disaster. Hurricane Preparedness Week during 2010 will be held May 23rd through May 29th.

The goal of this Hurricane Preparedness Web site is to inform the public about the hurricane hazards and provide knowledge which can be used to take ACTION. This information can be used to save lives at work, home, while on the road, or on the water.
Member Since: July 3, 2005 Posts: 428 Comments: 129833
Quoting Stormchaser2007:
Pretty interesting read.

Basically they're forecasting 24-27 storms, 14-16 hurricanes, and 6-7 intense hurricanes.


They nailed last year. Really interested to see how they do this year. I do believe they are overdoing it a bit though.
27 Named storms, wow, I hope that they're wrong. Ufff, I'm not liking this graph, My neck of the woods (Miami) In red.

Member Since: September 2, 2009 Posts: 130 Comments: 21194
Last Viz frame today as 90L Pops a few storms at Sunset.





Member Since: July 3, 2005 Posts: 428 Comments: 129833
Quoting Stormchaser2007:
Pretty interesting read.

Basically they're forecasting 24-27 storms, 14-16 hurricanes, and 6-7 intense hurricanes.


They nailed last year. Really interested to see how they do this year. I do believe they are overdoing it a bit though.


Jesus.. thats 2005 level activity.
Someone say 6,000 posts a day in this season?
Wow.. thats just astonishing.. no words to describe.
Member Since: Posts: Comments:


AOI

AOI

AOI

AOI

Humor in Comments
Member Since: Posts: Comments:
90L

2km Storm Relative IR Imagery with BD Enhancement Curve
2345 UTC

Member Since: July 3, 2005 Posts: 428 Comments: 129833
if we do get a storm in the Caribbean where will it go? does the gulf coast have to watch this, or is this going to be a Caribbean system? i think that 90l will still be there Tuesday and its still possible that it will regain strength. is 90l going to make landfall or is this going to be a fish storm? i know what the nhc and weather channel people think but i hold the opinion of the people on this site higher. thanks in advance for any answers.
Member Since: September 10, 2008 Posts: 0 Comments: 1294
90L Multiplatform Satellite Surface Wind Analysis 1800 UTC
Member Since: July 3, 2005 Posts: 428 Comments: 129833
AMSU Microwave 89GHz Imagery (4 km Mercator)
1818 UTC

Member Since: July 3, 2005 Posts: 428 Comments: 129833
Yellow...say it aint so. :) Looks like they are picking up on the EPAC blob as well. NHC got called into work a week early.
Member Since: Posts: Comments:
Quoting Stormchaser2007:
Pretty interesting read.

Basically they're forecasting 24-27 storms, 14-16 hurricanes, and 6-7 intense hurricanes.

They nailed last year. Really interested to see how they do this year. I do believe they are overdoing it a bit though.


Glad you read it too, I posted it last night. Its really interesting. I have never heard of the GLAAM (total vorticity of the earth) but it makes sence!
Member Since: Posts: Comments:
Quoting Stormchaser2007:
Pretty interesting read.

Basically they're forecasting 24-27 storms, 14-16 hurricanes, and 6-7 intense hurricanes.


They nailed last year. Really interested to see how they do this year. I do believe they are overdoing it a bit though.


They probably are. I mean, they are pretty much forecasting a very similar year to 2005 in terms of activity. Will be interesting to see what happens.
Member Since: Posts: Comments:
Quoting Mikla:
Pretty good winds at buoy 41048:


That may get ALEX designated if the data verifies for a while.

Conditions at 41048 as of
(7:50 pm EDT)
2350 GMT on 05/24/2010:
Unit of Measure: Time Zone:

Click on the graph icon in the table below to see a time series plot of the last five days of that observation.
5-day plot - Wind Direction Wind Direction (WDIR): ENE ( 70 deg true )
5-day plot - Wind Speed Wind Speed (WSPD): 36.9 kts
5-day plot - Wind Gust Wind Gust (GST): 44.7 kts
5-day plot - Wave Height Wave Height (WVHT): 18.7 ft
5-day plot - Dominant Wave Period Dominant Wave Period (DPD): 11 sec
5-day plot - Average Period Average Period (APD): 7.7 sec
5-day plot - Atmospheric Pressure Atmospheric Pressure (PRES): 29.84 in
5-day plot - Pressure Tendency Pressure Tendency (PTDY): -0.03 in ( Falling )
5-day plot - Air Temperature Air Temperature (ATMP): 69.6 F
5-day plot - Water Temperature Water Temperature (WTMP): 72.1 F
5-day plot - Dew Point Dew Point (DEWP): 65.8 F
Member Since: July 3, 2005 Posts: 428 Comments: 129833
Dr. Jeff Masters excerpt from the Spuds McKenzie show on WWL.com Radio NOLA today.

Member Since: July 3, 2005 Posts: 428 Comments: 129833
Quoting nrtiwlnvragn:


You got a link, paper or something to that effect. NHC has previously requested a version of the GFDL without the "bogus" storm to use for cyclogenesis.


http://www.nws.noaa.gov/om/tpb/472bbody.html

http://www.gfdl.noaa.gov/operational-hurricane-forecasting
Member Since: Posts: Comments:
Pretty interesting read.

Basically they're forecasting 24-27 storms, 14-16 hurricanes, and 6-7 intense hurricanes.


They nailed last year. Really interested to see how they do this year. I do believe they are overdoing it a bit though.
Member Since: Posts: Comments:
749. Mikla
Pretty good winds at buoy 41048:
Member Since: Posts: Comments:
if we do get a storm in the Caribbean where will it go? does the gulf coast have to watch this, or is this going to be a Caribbean system? i think that 90l will still be there Tuesday and its still possible that it will regain strength. is 90l going to make landfall or is this going to be a fish storm? i know what the nhc and weather channel people think but i hold the opinion of the people on this site higher. thanks in advance for any answers.
Member Since: September 10, 2008 Posts: 0 Comments: 1294
Its probable that the area on the EPAC will drift into the Caribbean and develop a low pressure of some sort by the 28th.. I won't speculate out farther than that.
Member Since: Posts: Comments:
Geauxjira: The Movie

2nd story here...

humidcity.com
Member Since: July 3, 2005 Posts: 428 Comments: 129833
Member Since: July 3, 2005 Posts: 428 Comments: 129833
Honestly, shear is forecast to remain marginal, water temps are minimal, and an upper level low is colliding with 90L. There was really no reason to say it's dissipating, it's also looking better on the IR. It's not a fact that 90L will be deactivated, but it's also NOT a fact that 90L will beat the odds and become Subtropical Storm Alex. So it's a wait and see.. The Carribean looks to be getting interesting in a few days.
Member Since: Posts: Comments:
hey guys that E Pac AOI is not going anywhere but the SW CAribbean

Member Since: June 13, 2009 Posts: 2 Comments: 12716
Quoting weathersp:


The Hurricane models (GFDL+HWRF) are NOT to be used outside of the area in which the the storm they initalised for. Thats not what they were designed for, use global models instead.


You got a link, paper or something to that effect. NHC has previously requested a version of the GFDL without the "bogus" storm to use for cyclogenesis.
Member Since: Posts: Comments:
741. IKE
Quoting nrtiwlnvragn:


Ya but the timing between the two are off. TAFB is 72 hours, GFDL has a low in the same general area at 102 hours. They could be the same just TAFB see quicker.


I see what you mean...difference of about a day.
Member Since: June 9, 2005 Posts: 23 Comments: 37860
Quoting IKE:


Also that map you just recently posted that showed a dissipating low in 72 hours in the Caribbean....it shows up on the 18Z GFDL run with a more potent low further SW...probably 91L.


Ya but the timing between the two are off. TAFB is 72 hours, GFDL has a low in the same general area at 102 hours. They could be the same just TAFB see quicker.
Member Since: Posts: Comments:
My bets are on the Caribbean for Alex now.


90L should be declassified within the next 48 hours.
Member Since: Posts: Comments:
Well.. I'm starting to doubt highly development of 90L, about a 10% chance for me now.. We could see a deactivation by tomorrow morning.. watch the Caribbean closely.. my bets on Alex are there..
Member Since: Posts: Comments:
Quoting weathersp:


The Hurricane models (GFDL+HWRF) are NOT to be used outside of the area in which the the storm they initalised for. Thats not what they were designed for, use global models instead.


It doesn't mean that they cannot be correct in what they are seeing

I have seen many examples of them predicting a future storm while being used to track a current one.
Member Since: March 10, 2010 Posts: 1 Comments: 7874
Quoting weathersp:


The Hurricane models (GFDL+HWRF) are NOT to be used outside of the area in which the the storm they initalised for. Thats not what they were designed for, use global models instead.
It was only meant for entertainment, I'm just pointing out what it is showing.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
I'm still giving 90L a medium chance for transition to Subtropical status, just because the system looks rough on satellite doesn't mean it has a lower chance, but I respect the NHC decision. 90L appears to be getting more defined on the IR, so I guess the truth will be told by tomorrow. Dissipates or becomes Alex? we'll see.
Member Since: Posts: Comments:

Viewing: 784 - 734

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
26 °F
Overcast

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron