Category 3 Hurricane Earl pounding northern Lesser Antilles and Puerto Rico

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

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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

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this what i been waiting for


invest_RENUMBER_al972010_al082010.ren
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1630. jasblt
Alright, I understand almost everyone in here thinks they are weather forecasters. Some insist it's already moving northwest when Sats shows it's not. Arguing back and forth is wasting space here. We have a serious storm on our hands, wishing it to move one way or another because of a wobble and then arguing your point is doing no good for anyone. Even if we don't have a direct hit on the CONUS, everyone on the east coast is going to feel some effect from EARL. What I hope doesn't happen, is that he rakes the entire east coast, which could happen if this so called right turn doesn't happen soon..Best of luck to all in his path. Like Storm said...this is the beginning.
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1629. markot
weathermanplz look at radar it is moving west.... ok
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1628. KEEPEROFTHEGATE (Mod)
07L/MH/E/C4
MARK
19.27N/64.51W
Member Since: July 15, 2006 Posts: 171 Comments: 53839
I think I see a pinhole eye!
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1625. kwgirl
Quoting katrinakat5:
kwgirl the trofyou think will turn earl to keep itfrom hitting the east coast is a very shallow trof..it will not dig as far south in lat like the other one did this is a much weaker trof and will have little effect on earl...
I'm just waiting to see. But it makes me feel more confident that maybe it will turn or perhaps suck in some dry air to knock some strength out of it. But I am keeping my eye on it.
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Quoting winter123:
Have a look at these crazy track forecasts!




So basically they will absorb each other?

And this one is poised to make a rare hit on North Korea, which has only been hit like 3 times in 50 years.
Hasn't the Atlantic had some crazy tracks like that? I think it was either jeanne or Francis that did a loop-de-loop
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1623. angiest
Quoting MiamiHurricanes09:
000
WTNT52 KNHC 301953
TCEAT2
HURRICANE EARL TROPICAL CYCLONE POSITION ESTIMATE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072010
400 PM AST MON AUG 30 2010

AT 4 PM AST...THE CENTER OF HURRICANE EARL WAS ESTIMATED FROM SAN
JUAN DOPPLER RADAR NEAR LATITUDE 19.2 NORTH...LONGITUDE 64.5 WEST
OR ABOUT 120 MILES...190 KM...EAST-NORTHEAST OF SAN JUAN PUERTO
RICO.

$$
FORECASTER BROWN/BERG



That's a movement at about 305 degrees from the 2PM fix.
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We have Tropical Storm Fiona!
invest_RENUMBER_al972010_al082010.ren
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Quoting moonlightcowboy:



Hey, katadman. Seems you sort of answered your own question. That's how I see it, too.


Good to see you, MLC. Where is beel?
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BEGIN
NHC_ATCF
invest_RENUMBER_al972010_al082010.ren
FSTDA
R
U
040
010
0000
201008301952
NONE
NOTIFY=ATRP
END
Member Since: August 23, 2008 Posts: 7 Comments: 5300
1619. flsky
Quoting winter123:

This has to be a CMC doomcast. Cat 5 just west of manhattan. Only CMC.

Seriously though, one wobble west (not to mention Earl has been trending west it's entire lifetime) would mean New England landfall. Probably as a major.

CMC has been pretty astute at times in the past.
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97L is a tropical storm? Or is Fiona an invest? What??
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Have a look at these crazy track forecasts!




So basically they will absorb each other?

And this one is poised to make a rare hit on North Korea, which has only been hit like 3 times in 50 years.
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This is one heck of a Hurricane!
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000
WTNT52 KNHC 301953
TCEAT2
HURRICANE EARL TROPICAL CYCLONE POSITION ESTIMATE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072010
400 PM AST MON AUG 30 2010

AT 4 PM AST...THE CENTER OF HURRICANE EARL WAS ESTIMATED FROM SAN
JUAN DOPPLER RADAR NEAR LATITUDE 19.2 NORTH...LONGITUDE 64.5 WEST
OR ABOUT 120 MILES...190 KM...EAST-NORTHEAST OF SAN JUAN PUERTO
RICO.

$$
FORECASTER BROWN/BERG

Member Since: Posts: Comments:
Quoting stoormfury:
looks like FIONA is born invest 97L has winds of 40 mph


It needs more storms.. Just right now it has a nice spin and coc.. But i believe it will develop more storms soon..
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GFS calling for up to 4 inches of rain on the OBX in 4 days.

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Quoting jcpoulard:


I monitor that also, even if it keep a 285 degree track this will bring large band of rain to the northern part of Haiti and the city of Gonaives could flood again for the third time (Jeanne 2004 was not so strong) but remember IKE (2008 who stay at a well 150 miles North of haiti. Keep have a eye on this one.
Haiti is still going to get a bunch of miserable rain anyway from Earl...He is Huge
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1611. hydrus
Quoting CybrTeddy:
I think Earl could peak at 150 before a EWRC.

Category 5 isn't out of the question however, just they are pretty rare in the Atlantic. The last one was Hurricane Felix and the last one out in the Atlantic Ocean vs the Caribbean or the Gulf was Hurricane Isabel, 7 years ago.
I think it will reach-5. Only because of the Dvorak image. However, notice the flattening on the N.W.quadrant. Could be a sign of shear in that area.
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Quoting stoormfury:
watches and warnings will be initiated at 5pm advisories on tropical storm Fiona


Where did you hear this?
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1609. angiest
Over the last two hours I see Earl moving at ~305 degrees, which is to the right of earlier in the day.
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And the last few frames gives Earl an appearance of a more westerly track because the eye is wobbling. I wouldn't be surprised if an eyewall replacement cycle develops later this evening.
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watches and warnings will be initiated at 5pm advisories on tropical storm Fiona
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1605. GetReal
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Quoting Flyairbird:
Hello my name is Earl....and I carry a nice swirl. lol
Where's Crabman and Joy? LOL
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Thanks for the radar image of Earl moving "West".

Now visit this link and make sure you click on L/L (which stands for Latitude/Longitude).

He's definitely gaining ground on latitude....slowly but surely...

http://www.ssd.noaa.gov/goes/flt/t2/flash-rb.html
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Storm,

what are your thoughts on 97L as far as direction and intensity?
Member Since: July 12, 2010 Posts: 0 Comments: 1130
Quoting Tazmanian:



C and B


E very close call but E for sure
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1600. GetReal
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1597. markot
what... look at radar isnow moving west...ok
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Quoting Waltanater:
Earl has been going West for the past 2 hours now! http://www.ssd.noaa.gov/goes/flt/t2/flash-vis.html

It seems that the expert forcasters are "hanging on" to those models until the very last minute. Every new run, the paths are looking more and more crunched up together as they stay conveniently off shore and not even making landfall. No outlier here. Is this to avoid\minimize mass panic? I feel there is something wrong here, in general. Something has to, and will give. If and where this hits, it will be very, very bad.

Anyone else feel the same way? I welcome your opinions (based on fact of course)
CONSPIRACY!
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Quoting mossyhead:
I am getting worried for Haiti. I know it is suppose to turn NW, but what a disaster for Haiti if it does not.


I monitor that also, even if it keep a 285 degree track this will bring large band of rain to the northern part of Haiti and the city of Gonaives could flood again for the third time (Jeanne 2004 was not so strong) but remember IKE (2008 who stay at a well 150 miles North of haiti. Keep have a eye on this one.
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Quoting luigi18:

Dr Storm did Earl is moving now west or is my screen?
Yes it is moving WEST!
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1592. JeffM
NHC cone seems to be moving slightly east away from OBX since 8am but is nudging west from CT and above.
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looks like FIONA is born invest 97L has winds of 40 mph
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Huh?

And, the CIMSS site (parts at least) is down.
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Quoting Krycek1984:


Very true...I'm in Cleveland...and it's too hot for late August, that's for sure, and forecast to stay that way til Thursday afternoon...originally it was only suppose to be in the 90's til Wednesday.
You guys are just up the road a piece...I'm down in columbus
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1587. hydrus
Quoting FLdewey:
Somebody has been eating their Wheaties...

I think he ate the whole box.
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For all the sensationalism, Earl IS following the track... within +/- 20nm... If you are waiting for a pronouced turn, you are not going to see that, the storm will continue to slowly bend to the right... the track points areseparated by 12 hours. Between the classic "stairstep" as was pointed out earlier and cycloidal motion, the instaneous track motion will be moving about as much as 30 or more degrees... but the integrated motion over time is very close to the track... at 8AM tomorrow morning Earl should be around 19.5/65.7... and that should be when you make your assessment... Yes, with a Cat 4 in the Atlantic everyone on the coast should pay attention... but Earl does not have a specific "Home on [Your name an location here]" mode...
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Quoting IKE:
One thing about Earl...he has become a large system.



And the models show him almost double this size as he is passing OBX... Even without a direct landfall somebody on the East Coast is likely to see major affects.
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1584. Relix
Quoting weatherman566:
I'm not sure if I can continue reading posts on this blog. Earl is definitely not moving to the west. Can you not read the satellite imagery? He's moving the WNW, and if you look at the overall system, I've seen more of a NW movement than before.

Let's not get overly hyped on this storm.


Look at the radar for God's sake.

http://radar.weather.gov/radar.php?rid=JUA&product=N0Z&overlay=01101111&loop=yes
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For those needing i have put up 3 seperate Interactive Floaters up on Earl under the tab Storm Center Observations. Also have 1 floater up on 97L. I can't put more than 4 Floaters up or it will slow everything down.....4 might make things to slow but, it is working for me. Let me know if your having trouble and i will take 1 floater off.
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Quoting IKE:
One thing about Earl...he has become a large system.



I was looking at that too Ike.....Pretty large impact wherever he ends up....Unfortunately, this may end up as beach erosion city for the Eastern Seabord with not a lot of sand protection left over for the next ones this season.....Enjoy the beaches now while you can.
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.