Category 3 Hurricane Earl pounding northern Lesser Antilles and Puerto Rico

By: Dr. Jeff Masters , 2:40 PM GMT on August 30, 2010

Share this Blog
5
+

An intensifying Hurricane Earl is pounding Puerto Rico and northern Lesser Antilles Islands with heavy rain and high winds this morning. The eye of Earl passed just north of Anguilla at 9am EDT, and Juliana airport on neighboring St. Martin Island recorded sustained winds of 47 mph, gusting to 68 mph at 8am EDT before going silent. An Air Force Hurricane Hunter aircraft currently in Earl just found a central pressure of 960 mb at 9:42 am EDT. This is a significant drop of 25 mb in 25 hours. Top flight level winds at 10,000 feet seen by the Air Force aircraft were 128 mph. Using the usual rule of thumb that the surface winds are 90% of the 10,000 foot flight level winds gives one surface winds of 115 mph, which is right at the border of Cat 2/ Cat 3 strength. Top winds seen at the surface by the Air Force's SFMR instrument were lower, 104 mph. Recent satellite imagery shows that Earl is not perfectly symmetrical--there is still fewer heavy thunderstorms on the hurricane's north side, suggesting that upper-level northerly winds are bringing 5 - 10 knots of wind shear to the storm.


Figure 1. Radar image of Earl taken at 7am EDT 8/30/10 from the St. Maarten radar. Image credit: Meteorological Service of the Netherlands Antilles and Aruba.

Outlook for the Caribbean islands today
Latest radar animations out of Puerto Rico and St. Marten show that the eye of Earl is on track to pass just to the northeast of the islands of Anguilla, St. Maarten, and The Settlement in the British Virgin Islands today. The periphery of Earl's southern eyewall will probably bring Category 1 hurricane conditions to some of these islands today. NHC is giving its highest odds for hurricane-force winds to Saint Maarten--a 99% chance. These odds are 4% for St. Thomas in the Virgin Islands, and 2% for San Juan, Puerto Rico. The main threat to Puerto Rico will be heavy rains--up to eight inches in isolated areas. Earl's rains, in addition to causing flooding and dangerous landslides, will also help alleviate drought conditions that have affected many of the islands this year.

Intensity forecast for Earl
Wind shear as diagnosed by the latest SHIPS model forecast is nearly non-existent over Earl--just 3 knots--put is probably higher than that, based on the fact that the northern portion of Earl cloud pattern is ragged. Further evidence of this is the fact that Earl's eyewall had a gap in its west side, according to the latest report from the Hurricane Hunters. Ocean temperatures are a near-record 30°C, and very warm waters extend to great depth, resulting in a total ocean heat content highly favorable for rapid intensification. These nearly ideal conditions for intensification should bring Earl to Category 4 strength by Tuesday morning, and Category 5 is not out of the question. Earl should be able to maintain major hurricane status through Thursday, when it will make its closest approach to North Carolina. Sea surface temperatures are very warm, 29°C, along the U.S. East Coast, and wind shear is expected to remain low through Thursday. By Friday, when Earl will be making its closest approach to New England, wind shear will rise to a high 20 - 30 knots and ocean temperatures will plunge to 20°C, resulting in considerable weakening. Earl will still probably be a Category 2 hurricane on Friday, when it could potentially make landfall in Massachusetts or Nova Scotia, Canada.


Figure 2. Swath of surface winds from Earl predicted by the 2am EDT Monday August 30, 2010 run of NOAA's GFDL model. Hurricane force winds (yellow colors, 64 kt and above) are predicted to stay off the coast and tropical storm force winds (light green colors, 34 knots and above) are predicted to stay off the U.S. coast, but affect the coast of Canada. Image credit: Morris Bender, NOAA/GFDL.

Track forecast for Earl
Once Earl passes the Lesser Antilles, steering currents favor a northwesterly course towards North Carolina. History suggests that a storm in Earl's current location has a 25% chance of making landfall on the U.S. East Coast, and Earl's chances of making a U.S. landfall are probably close to that. None of the computer models show Earl hitting the U.S., but the storm will likely come uncomfortably close to North Carolina's Outer Banks and to Massachusetts. The latest set of model runs (2am EDT, or 6Z) project Earl will miss North Carolina by 200 - 300 miles on Thursday, and Massachusetts by a similar distance on Friday. Keep in mind that the average error in a 4 - 5 day NHC forecast is 200 - 300 miles, so the East Coast cannot breathe easily yet. The Outer Banks of North Carolina and Cape Cod, Massachusetts are both at the edge of the cone of uncertainty. NHC is giving Cape Hatteras a 9% chance of receiving hurricane force winds. These odds are 14% for Nantucket, 4% for Boston, and 2% for New York City. The main determinant of whether Earl hits the U.S. or not is a strong trough of low pressure predicted to move off the U.S. East Coast Friday. This trough, if it develops as predicted, should be strong enough to recurve Earl out to sea late in the week, with the storm just missing landfall in the U.S., but possibly making landfall in Nova Scotia, Canada.

Regardless of Earl's exact track, the U.S. East Coast can expect a long period of high waves beginning on Thursday. Significant beach erosion and dangerous rip current will be the rule, due to waves that will reach 10 - 15 feet in offshore waters (Figure 3.)


Figure 3. Wave forecast for 8am Friday, September 3, 2010, as produced by the 8pm EDT August 29 run of NOAA's Wavewatch III model. The model is predicting waves of 4 - 5 meters (13 - 16 feet) in the offshore waters from North Carolina to New Jersey.

Hurricane History for the northern Lesser Antilles
The last Cape Verdes-type hurricane to affect the Barbuda and the surrounding northern Lesser Antilles Islands was Hurricane Debby of 2000, which passed over the islands on August 28 as a Category 1 hurricane. Damage was less than $1 million, and no fatalities were reported. The last hurricane of any kind to pass through the northern Lesser Antilles Islands was Category 4 Hurricane Omar, on October 16, 2008. Omar took an unusual track, moving towards the northeast, and the storm's eyewall missed all of the islands. Omar did $80 million in damage to the Caribbean, mainly on the islands of Antigua, Barbuda, Dominica, the SSS Islands (Saba, St. Eustatius, and St. Maarten), and the U.S. Virgin Islands. No direct deaths were attributed to Omar, and the name Omar was not retired from the 6-year rotating list of hurricane names.

Links to track Earl
Wundermap of the northern Lesser Antilles Islands
Long range radar out of San Juan, Puerto Rico
Visible rapid scan satellite loop

97L
The tropical wave (Invest 97L) now 1000 miles east of the Lesser Antilles Islands has a well-defined surface circulation and enough heavy thunderstorms to be classified as a tropical depression, if it can maintain that state for another six or so hours. Satellite loops show the surface circulation clearly, but also that heavy thunderstorm activity has been slow to build. The storm is experiencing low wind shear of less than 5 knots, and is over warm 29°C waters. The main impediment to development continues to be dry air associated with the Saharan Air Layer (SAL) surrounding the storm. The latest SHIPS model forecast calls for shear to stay in the low range, 5 - 10 knots, through Tuesday, and this should allow 97L to organize into a tropical depression today or Tuesday. NHC is giving 97L a 90% chance of developing into a tropical depression by Wednesday.

97L is moving quickly to the west, at about 20 mph. This means it is catching up to Earl, which has slowed down to 14 mph. By Tuesday night, Earl is expected to be a large and powerful major hurricane with a well-developed upper-level outflow channel heading clockwise out from Earl's center at high altitudes. These strong upper-level winds will bring high levels of wind shear, 20 - 30 knots, to 97L, and probably arrest the storm's development. The most likely scenario depicted in the computer models is for 97L to be drawn into the low pressure wake of Earl and pass to the northeast of the Lesser Antilles. Earl would then eventually destroy 97L through high wind shear, and by robbing the storm of its moisture. An alternative scenario is that 97L will stay far enough away from Earl that it will be able to pass through the northern Lesser Antilles islands as a tropical storm on Wednesday and Thursday, then bend northwestwards to potentially threaten the Bahamas and U.S. East Coast. There is a very high degree of uncertainty on what may happen to 97L. History suggests that a storm in 97L's current location has a 25% chance of making landfall on the U.S. East Coast.


Figure 4. Morning satellite image of 97L.

Danielle
Hurricane Danielle is on its way to oblivion over the cold North Atlantic waters, and is only of concern to shipping interests.

Elsewhere in the Tropics
Over in the Western Pacific, tropical cyclone activity is ramping up, with two named storms expected to affect land this week. As is typical in a La Niña year, these storms have developed close to mainland Asia, and don't have a lot of time over water to intensify into strong typhoons. The storm of most concern is Typhoon Kompasu, which is expected to hit Okinawa today and recurve northward into Korea on Thursday. It now appears the Kompasu will not have major impacts on China's largest city, Shanghai. In the South China Sea, the fearsome sounding Tropical Storm Lionrock is forecast to hit the Chinese coast near Hong Kong on Tuesday, but is not predicted to develop into a typhoon.

The GFS model is predicting formation of a tropical depression off the coast of Africa about seven days from now.

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: 1781 - 1731

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 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43Blog Index

Just a random question: Has a fujiwahra ever happen between 3 storms?
Member Since: Posts: Comments:
Quoting Relix:
To weatherman455

Sorry, these are not 3 frames.



W > WNW> W> WNW again.


look at Earls position in the radar image from Dr Masters post this morning and look where it is now. You've been screaming 'west' all day. How did it vet to where it is now going much more west than north??
Member Since: Posts: Comments:
1779. Asta
Member Since: Posts: Comments:
1778. angiest
Quoting MiamiHurricanes09:
Ummm, pretty obvious this thing is jacked up, lol.

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 30 AUG 2010 Time : 191500 UTC
Lat : 19:08:39 N Lon : 64:22:59 W


CI# /Pressure/ Vmax
6.3 / 941.7mb/122.2kt


Final T# Adj T# Raw T#
6.1 6.0 6.3

Latitude bias adjustment to MSLP : +1.5mb

Estimated radius of max. wind based on IR : 17 km

Center Temp : +7.4C Cloud Region Temp : -68.9C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : 1.7T/6hr
Weakening Flag : ON
Rapid Dissipation Flag : OFF


I think earlier today it had the Rapid Dissipation Flag marked on.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
1777. yoboi
when did hurricane earl form????
Member Since: Posts: Comments:
Quoting StSimonsIslandGAGuy:
Not a fictional storm. It's Georgia's last major, from 1898. We had a storm surge 18 feet above high tide. Cat 4 landfalling at Cumberland Island at 1 pm Oct 2, 1898.


I know, I was just joshin' ...Giving you a hard time for sitting right in the middle of the "forbidden" or "protected" zone.
Member Since: Posts: Comments:
Member Since: Posts: Comments:


Earl is on its way to becoming a CAT 5... maybe tomorrow morning
Member Since: November 7, 2008 Posts: 0 Comments: 42
Member Since: Posts: Comments:
Quoting TopWave:
Storm W ,

Does Earl have annular characteristics like Hurricane Isabel? They seem to have very similar characteristics and even the storm tracks are somewhat similar at the moment.

Absolutely not.
Member Since: Posts: Comments:
1770. GetReal



Something has to change with Earl's direction and speed, it is just when it will occur.
Member Since: Posts: Comments:
1768. KEEPEROFTHEGATE (Mod)
07L/MH/E/C4
MARK
19.37N/64.65W
Member Since: Posts: Comments:
Quoting katrinakat5:
connie every time they post a new track it will shift west sou fla will be in the cone by late tuesday....


What do you consider South Florida?

Don't eat anything tomorrow except those words.
Member Since: Posts: Comments:
1766. angiest
Quoting TopWave:
Storm W ,

Does Earl have annular characteristics like Hurricane Isabel? They seem to have very similar characteristics and even the storm tracks are somewhat similar at the moment.


No, look at the radar. Spiral banding is evident. An annular hurricane wouldn't show spiral bands like that.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
1765. Drakoen
Quoting StSimonsIslandGAGuy:
I am referring to this image. Why would Earl then not get steered to Florida? What don't I see?



That only represents what is current. If you look you can see the trough axis (weakness)east of the ridge axis center over the mid-Atlantic states.

You should go here: http://www.meteo.psu.edu/ewall/COMPSTEERATL_12z/comploop.html to see the changes in the steering.
Member Since: Posts: Comments:
Quoting washingtonian115:
If fiona wants to live she better slow down.

True Dat.
Member Since: Posts: Comments:
Quoting StSimonsIslandGAGuy:
Not a fictional storm. It's Georgia's last major, from 1898. We had a storm surge 18 feet above high tide. Cat 4 landfalling at Cumberland Island at 1 pm Oct 2, 1898.


Man you must be old! j/k
Member Since: Posts: Comments:
When should these storms start taking a west track instead of out to sea? Or, is this how it should be this year too? (out to seas storms)
Member Since: Posts: Comments:
1761. angiest
Quoting 47n91w:


I did that this morning and currently it looks like 295 degrees on my Gr3.


I did reset mine recently. Trying to keep a good starting point.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
Quoting GoodOleBudSir:
Will Earl's wake hinder Fiona's development? TIA

Yes, it already has, imo.
Member Since: Posts: Comments:
Quoting StSimonsIslandGAGuy:
I am referring to this image. Why would Earl then not get steered to Florida? What don't I see?



I've been wondering the same thing. With heights over the Eastern US forecast to be in the 1018-1022 range over the next 2-3 days, what is going to influence Earl's northward component if the weakness does indeed get pinched off?
Member Since: Posts: Comments:
1758. DVG
Donna 1960 might be closer I think. Earl getting more west on it's stair step course, and then the ridge finally pulling Earl out.

Just throwing it out there as long as it's ok.
Member Since: Posts: Comments:
1756. TopWave
Storm W ,

Does Earl have annular characteristics like Hurricane Isabel? They seem to have very similar characteristics and even the storm tracks are somewhat similar at the moment.
Member Since: Posts: Comments:
If fiona wants to live she better slow down.
Member Since: Posts: Comments:
1754. leddyed
Quoting StormsAreCool:


They've been wrong every step of the way on this storm.


No, they have not.
Member Since: Posts: Comments:
Ummm, pretty obvious this thing is jacked up, lol.

UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 30 AUG 2010 Time : 191500 UTC
Lat : 19:08:39 N Lon : 64:22:59 W


CI# /Pressure/ Vmax
6.3 / 941.7mb/122.2kt


Final T# Adj T# Raw T#
6.1 6.0 6.3

Latitude bias adjustment to MSLP : +1.5mb

Estimated radius of max. wind based on IR : 17 km

Center Temp : +7.4C Cloud Region Temp : -68.9C

Scene Type : EYE

Positioning Method : RING/SPIRAL COMBINATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : 1.7T/6hr
Weakening Flag : ON
Rapid Dissipation Flag : OFF
Member Since: Posts: Comments:
1752. 47n91w
Quoting angiest:


That would be why I am putting a marker on grlevel3 at the position fixes the NHC gives us, and then eyeballing the center many frames later. And currently he is moving ~305 degrees. But I only recently placed my current marker so that is being affected by wobbles more so than normal.


I did that this morning and currently it looks like 295 degrees on my Gr3.
Member Since: Posts: Comments:
Quoting StSimonsIslandGAGuy:
I am referring to this image. Why would Earl then not get steered to Florida? What don't I see?



Under the current steering patterns, he'd be shunted south or to the northeast once he ran up against that E coast high.

The models are predicting a trof to move down and shove the Ecoast high aside somewhat, which Earl will then feel and move towards, and thus recurve.

That should be well in order by wednesday, from what I've seen so far, but then again we've been told to wait another 24 hours several times here.
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
They do appear to have enough distance from each other to not hinder each others' development and/or intensification.


Thx MH09 and Allstar
Member Since: Posts: Comments:
1749. HadesGodWyvern (Mod)
msmoma

Link

It means that an invest has become better organized to become identified as a tropical cyclone.. in this case TC 08L has been identified by the NRL.
Member Since: Posts: Comments:
Quoting Relix:
Amazing!

Over 15 birds have tried to take shelter in my house. Wow I didn't really believe those things but there are countless birds all around the house trying to take refuge. Man that's amazing. First time I go through that.

Where do you live?
Member Since: Posts: Comments:
Quoting ILwthrfan:


I agree there is no doubt Earl has had a consistant Northward bias to his westward movement. In other words hes more WNW and if anything slightly more N of WNW.


The start of this loop shows Earl's eye just brushing the north of Anguilla. It follows a very erratic course thereafter, but at the end of the loop the eye is almost exactly NW of its starting point.

Earl is clearly moving NW
Member Since: Posts: Comments:
Quoting Asta:


this looks like a monster
Member Since: November 7, 2008 Posts: 0 Comments: 42
1744. hydrus
Quoting angiest:


Earl looked awful most of his life.
And Danielle had her bad hair days too. It seems once they get within a few hundred miles of the islands, everybody starts lookin better.
Member Since: Posts: Comments:
1743. angiest
Quoting Chapelhill:
AT 300 PM AST...1900 UTC...THE CENTER OF HURRICANE EARL WAS LOCATED
NEAR LATITUDE 19.1 NORTH...LONGITUDE 64.4 WEST. EARL IS MOVING
TOWARD THE WEST-NORTHWEST NEAR 15 MPH...24 KM/HR. THIS GENERAL
MOTION IS EXPECTED TODAY AND TONIGHT...FOLLOWED BY A TURN
TOWARD THE NORTHWEST ON TUESDAY.

Is Earl farther west than forecast? not yet

Is he turning to the NW? not yet

The forecast is solid right now. Will their be some changes? yes, most likely.

Rapid deepening can cause a system to delay it's respose to a slight weakness, or an approaching trough, but we are still 12 to 16 hours out from expecting the shift to the NW.



Actually the turn NW was supposed to happen a couple of days ago. It has been delayed several times.
Member Since: August 26, 2006 Posts: 16 Comments: 4766
1742. markot
look at sat. photos its running on 19.2 line
Member Since: Posts: Comments:
1741. markot
look at sat. photos its running on 19.2 line
Member Since: Posts: Comments:
Quoting GoodOleBudSir:
Will Earl's wake hinder Fiona's development? TIA
They do appear to have enough distance from each other to not hinder each others' development and/or intensification.
Member Since: Posts: Comments:
Thx Allstar
Member Since: Posts: Comments:
1737. twooks
Quoting iammothernature:
POLL:

What intensity will Earl reach at its peak?

A. High Cat 4
B. Low Cat 5 (160-165 mph winds)
C. Mid Cat 5 (170-175 mph winds)

Where will Earl hit?

A. North Carolina
B. New York
C. Any other area of New England
D. Canada
E. Nothing


B and A
Member Since: Posts: Comments:
can someone please send factual data that Fiona has formed?

the potential future track of Fiona will be interesting. If the high builds in, Florida should be careful
Member Since: Posts: Comments:
1735. HadesGodWyvern (Mod)
2010AUG30 194500
CI 6.4
Pressure 939.1
MAX winds 124.6
Initial 6.3
Adjusted 6.7
Raw 6.7

----
T7.0 getting very close to radar appearance of how strong cyclone "EARL" appears.
Member Since: Posts: Comments:
Quoting StSimonsIslandGAGuy:
OK. Earl's course depicted by the models keeps shifting a bit more west with each run, it seems like.

Here is a question. It looks like there is a big high forecast to be on the east coast and the nearshore Atlantic this week. What will draw Earl to the north to the mid-Atlantic coast? I think everyone would be shocked if Earl made a landfall south of North Carolina, even the westcasters.

What are the reasons Earl wouldn't take a course like this?



No, I don't think something like this will happen; I trust the NHC not to make such a huge error, and I know they see things I don't. But what are they seeing? That steering map of GetReal's would make the course I put up seem like a northern outlier, not something out of bounds to the south and west.


That's a fictional storm right SSIG? Y'all don't get hit ;)

Sorry, not trying to jinx you!
Member Since: Posts: Comments:
1733. Bayside
Earl 5 day cone loop Link
Member Since: Posts: Comments:
Quoting Relix:
To weatherman455

Sorry, these are not 3 frames.



Lining up the radar image of Earl's eye with the top frame of your browser window will show you that even with Earl's westerly influenced movement he is not going due West. That said he is going more West than NW...so we can say as an overall movement pattern for multiple hours he has continued a WNW movement. For the moment...next three hours...? Guessing is all we are doing, even if informed guesssing.
Member Since: June 26, 2008 Posts: 0 Comments: 383
Quoting Tazmanian:
this what i been waiting for


invest_RENUMBER_al972010_al082010.ren


Where can I find that? and what does it mean?
Member Since: Posts: Comments:

Viewing: 1781 - 1731

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 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43Blog 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
28 °F
Overcast